Perinatal arterial ischemic stroke (AIS) occurs in an estimated 17 to 93 per 100000 live births, yet the etiology is poorly understood. Although investigators have implicated hypoxia as a potential cause of AIS, the role of hypoxia in AIS remains controversial. The aim of this study was to estimate the association between perinatal hypoxia factors and perinatal arterial ischemic stroke through a meta-analysis of published observational studies.A systematic search of electronically available studies published through July 2013 was conducted. Publication bias and heterogeneity across studies were evaluated and summary odds ratios (ORs) and 95% confidence intervals (CIs) were calculated with fixed-effects or random-effects models.A total of 8 studies describing the association between perinatal hypoxia factors and neonatal arterial ischemic stroke (AIS) met inclusion criteria, and 550 newborns with AIS were enrolled. The associations were found for AIS: preeclampsia , ventouse delivery , fetal heart rate abnormalities , reduced fetal movement , meconium-stained liquor , low Apgar score  and resuscitation at birth . Our data did not show any significant change of the mean risk estimate for oxytocin induction  and low arterial umbilical cord ph .There is a significant association between perinatal hypoxia factors and AIS. The result indicates that perinatal hypoxia maybe one of causes of AIS. Large scale prospective clinical studies are still warranted. Neonatal stroke is classified as either ischemic or hemorrhagic stroke, and ischemic stroke is further divided into arterial ischemic stroke (AIS) and cerebral sinovenous thrombosis (CSVT) The prevalence of PAIS has not been clearly determined. Lynch reported an estimated incidence of 71 in 1600 to 5000 births Perinatal arterial ischemic stroke is a main cause of cerebral palsy and other neurologic disabilities, thus making it a clinically relevant type of brain injury, yet the etiology is poorly understood.The pathogenesis of AIS is complex and multifactorial. Risk factors may be related to both maternal and placental problems as well as fetal and neonatal disorders, such as preeclampsia, chorioamnionitis, congenital heart malformations, hemolytic anemias, thrombophilic abnormalities, heart rate abnormalities, resuscitation at birth, low Apgar score, and abnormal cord ph The objective of this meta-analysis was to determine the impact of clinical risk factors or markers for hypoxia in neonates with arterial stroke. Our hypothesis is that clinical risk factors for hypoxia differ between newborns with stroke compared to normal controls.Studies included should be published, regardless of its design, publication language or date. Neonatal arterial ischemic stroke is generally defined as a cerebrovascular event occurring from birth to 28 days postnatal with radiological evidence of focal arterial infarction AIS neonates had to be with neurological clinical symptoms during the 28 first days of life, ischemic lesions in an arterial distribution revealed by suitable imaging methods. Neonates with infection of the central nervous system, brain malformations, venous infarction, cystic periventricular Leukomalaeia (PVL), or sinovenous thrombosis were excluded.The controls were randomly selected and were individually matched to the infants with PAIS for age and gestational age from the birth registry database or the same birth cohort. Those of a contemporaneous dataset from the general population selected as controls were also included.Two investigators (Lili Luo and Dapeng Chen) searched case-control or cohort studies published electronically and listed in database PubMed, EMBASE, Web of Science and Cochrane Library from initial to July 2013. The search terms were perinatal stroke, perinatal and neonatal ischemic stroke, neonatal arterial ischemic stroke, fetal stroke, and presumed prenatal or perinatal arterial ischemic stroke; prepartum complications, intrapartum complications and risk factor. Search consisted of a combination of one term from each group. Potential related studies about the association between hypoxia factors and AIS were first identified by screening the titles and abstracts of candidate articles, full manuscripts were then obtained. Further criteria for inclusion were then applied manually. Furthermore, a manual search was carried out from references cited in these articles. Otherwise we excluded studies with five or fewer cases, because of unreliability.We used the Newcastle-Ottawa Quality Assessment Scale to assess the quality of both cohort studies and case-control studies For data collection, two investigators used a form of data extraction, independently. Any areas of debate will be presented in the discussion. Studies were included in the meta-analysis only if approved by both investigators. First, we scrutinized in detail the literature on neonatal AIS to identify all possible risk factors which might cause hypoxia. We restricted our analysis to those for which an outcome was assessed by at least 5 cases, because of unreliability. During data extraction we recorded characteristics of the studies, including publication time, study design, country, sample size, gestational week, odds ratio, and 95% confidence intervals (CIs). We have included the studies with the largest number of participants if participant overlap between studies occurred. If original odds ratio and its 95% CI was not reported, the original number of participants was determined in order to calculate the odds ratio.We reviewed the possible hypoxia-related risk factors for AIS, included prepartum complications, intrapartum complications and infant characteristics. Among these factors exclusion criteria were: (1) patients less than 5 cases because of the uncertainty; (2) inconsistency of the diagnostic criteria. The association between risk factors and AIS was expressed as odds ratio (OR).All statistical analysis was performed using Stata 12.0. The pooled OR and its 95% confidence intervals (CIs) were calculated using either the Mantel–Haenszel formula (fixed-effect model) or the Dersimonian–Laird formula (random-effect model). A fixed-effect model was used when heterogeneity was not detected (P>0.10); otherwise, a random-effect model was used. For quantitative evaluation, OR was used to estimate the impact of risk factors on incidence of AIS. OR, variance, 95% CI, log (OR) and se (log (OR)) for each study were extracted or calculated by Stata 12.0 based on the published studies. The weight for each study is the inverse of study variance and variability between studies. A significant two-way P value for comparison was defined as P<0.05. Results are described using forest plots, where a single square represents an individual study's OR estimate. The pooled OR is symbolized by a solid diamond at the bottom of the forest plot and the width of the square represents the 95% CI of the OR. The size of the square represents the weight that the corresponding study exerts in the meta-analysis.2 value. I2>50% were considered to represent significant heterogeneity. Assessment of publication bias was performed for each of the pooled study groups using the Beggar's bias indicator test. The analysis of heterogeneity and publication bias was carried out using the statistical software Stata version 12.0.Statistical heterogeneity between studies was examined using both the Q statistic (significant at P<0.1) and the IWe identified 298 publications by our search strategy, except for the duplicate articles. Initial evaluation of abstracts identified 20 related articles, seven case-control studies and one cohort study with 550 patients were selected for analyses. After scrutinizing the literature, we yielded 18 possible risk factors . Among t2 = 3.90, P = 0.272, I2 = 23.2%) (Four studies (158 cases with AIS) were included in the meta-analysis. No significant heterogeneity was found (Chi= 23.2%) , so fixe= 23.2%) .2 = 1.94, P = 0.584, I2 = 0%) (Four studies (158 cases with AIS) were included in the meta-analysis. No heterogeneity was found (ChiI2 = 0%) , we usedI2 = 0%) .2 = 3.74, P = 0.291, I2 = 19.7%) (Four studies (152 cases with AIS) were included in the meta-analysis. No significant heterogeneity was found (Chi= 19.7%) , so fixe= 19.7%) .2 = 0.95, P = 0.813, I2 = 0%) (Four case-control studies (152 cases with AIS) were included in the meta-analysis. No heterogeneity was found (ChiI2 = 0%) , so fixeI2 = 0%) .2 = 0.03, P = 0.867, I2 = 0%) (Two studies (68 cases) included in the meta-analysis. There was not heterogeneity among included studies (ChiI2 = 0%) , fixed-e2 = 3.04, P = 0.551, I2 = 0%), we chose fixed-effect model to do the meta-analysis. This meta-analysis showed that meconium-stained liquor is significantly associated with AIS  (Estimates were reported from five retrospective case–control studies with 171 cases. No heterogeneity was found (Chito 4.60) . Visual to 4.60) .2 = 8.46, P = 0.037, I2 = 64.5%)  contributed to the meta-analysis. There was significant heterogeneity among included studies (Chi= 64.5%) , random-= 64.5%) .2 = 9.66, P = 0.008, I2 = 79.3%)  were included in the meta-analysis. There was heterogeneity among included studies (Chi= 79.3%) , random-= 79.3%) .2 = 0.21, P = 0.976, I2 = 0%) (Three retrospective and one prospective case-control studies (423 cases) contributed to the meta-analysis. There was not heterogeneity among included studies (ChiI2 = 0%) , fixed-eI2 = 0%) .Our Study included 8 studies and 550 newborns with AIS. The pooled analysis indicates that the associations were found for AIS: preeclampsia , ventouse delivery , fetal heart rate abnormalities , reduced fetal movement , meconium-stained liquor , low Apgar score  and resuscitation at birth . Our data did not show any significant change of the mean risk estimate for oxytocin induction  and low arterial umbilical cord ph .Neonatal arterial ischemic stroke is the most common form of cerebral infarction in children, and a leading cause of lifelong neurodevelopmental disabilities. Although the diagnosis is easily confirmed by neuro-imaging The preeclampsia usually is associated with abnormalities in the development of placental vessels. And hypoxia is one of the critical components in the pathogenesis of preeclampsia Fetal heart rate abnormalities and reduced fetal movement have been routinely considered as predictors of fetal distress. As meconium passage is associated with reduced cerebral artery pulsatility index, some evidence suggests that meconium-stained amniotic fluid may reflect fetal hypoxia Apgar score is a sum of values assigned to an infant, with a score of 7 or more indicating that the baby is in good to excellent condition In most centers, an umbilical cord ph of 7 to 7.1 is considered mild or moderate academia, with severe acidemia occurring when the ph is below 7. It has been proposed that neonatal complications are associated with metabolic rather than respiratory acidosis Resuscitation at birth usually refers to intubation, assisted ventilation, chest compressions, or cardiac medication. Neonates had transient hypoxia that needed resuscitation at birth. Kirton found that children with arterial presumed perinatal ischemic stroke were more likely to have neonatal resuscitation Preeclampsia and ventouse delivery are intrapartum complications, both may cause neonatal hypoxia. Fetal heart rate abnormalities reduced fetal movement, meconium-stained amniotic fluid, low Apgar score and resuscitation at birth, all of which are recognized markers of perinatal hypoxia. All of them were more common in AIS cases than in control subjects. Our results suggested a role of perinatal hypoxia in the development of AIS. The same characteristics of neonatal distress suggest that shared pathological mechanisms for perinatal stroke and neonatal encephalopathy may exist, and both pathologies can furthermore coexist in the same baby, as shown by Ramaswamy AIS and global hypoxic-ischemic encephalopathy likely share risk factors and AIS can occur alongside hypoxic-ischemic encephalopathy. In Wu et al, 17% of infants with AIS had a low Apgar score, but 0.9% from a normal cohort had a low Apgar score Our findings imply that AIS is more often associated with a complicated gestational course and delivery, resulting in fetal distress or hypoxia. Since the occurrence of stroke in this cohort was more frequent than in population-based data, neuro-imaging should be performed in these infants. And the study comparing neonates with seizures caused by stroke with seizures caused by HIE reported that seizure onset >12 h and clinically observed focal seizures are more often associated with AIS Although there is data about the risk factors for AIS, knowledge is still limited. In our meta-analysis, most of the included studies were designed retrospectively. Given the retrospective nature of these studies, it follows that bias towards risk factors may have occurred in the more severe cases File S1PRISMA Checklist.(DOC)Click here for additional data file.


Background. Hepatocellular carcinoma (HCC) represents the sixth common cancer in the world. Single nucleotide polymorphisms (SNPs) in microRNA genes may be associated with susceptibility to HCC. Recently, several studies have reported possible associations of SNPs miR-499 T>C rs3746444 and miR-34b/c T>C rs4938723 with the risk of HCC. However the results are inconsistent and inconclusive. In this present study, we conducted a meta-analysis to comprehensively evaluate potential associations between the two SNPs and HCC susceptibility. Methods. Through a systematic literature search, 8-case-control studies involving 5464 subjects were identified and included in this meta-analysis. The association between the two common SNPs and HCC risk was estimated by pooled odds ratios (ORs) and 95% confidence intervals (95% CIs). Our results showed no significant association between rs3746444 and susceptibility to HCC, whereas variant genotypes of rs4938723 were associated with increased HCC risk in allele frequency model and heterozygous model . Conclusions. The current evidence did not support association between rs3746444 and HCC risk. SNP rs4938723 may be associated with susceptibility to HCC. Further well-designed studies are required to clarify the relationships between the two SNPs and HCC risk.  Hepatocellular carcinoma (HCC) represents the most common primary malignancy of the liver. According to epidemiological survey, the prevalence of HCC ranks the sixth among all cancers. Although the diagnosis and treatment of HCC have significantly been improved in recent years, the prognosis remains poor. HCC accounts for approximately 700,000 cancer-related deaths per year, which ranks the third in global cancer statistics , 2. The Recent studies indicate that genetic factors may play important roles in the development of HCC . MicroRN Single nucleotide polymorphisms (SNPs) are the most common genetic variations in population. Numerous SNPs in or around miRNA-coding genes have been identified, and their roles in human cancer have been implicated , 13. RegA comprehensive computerized literature search was conducted in multiple online databases including PubMed, EMBASE, ISI Web of Science, the Cochrane Library, China National Knowledge Infrastructure (CNKI), Wanfang Database, and VIP Info database with the combination of the following search terms: “miR-499,” “miR-34,” “rs3746444,” “rs4938723,” “hepatocellular carcinoma,” “liver cancer,” “hepatoma,” and “HCC” to identify potentially relevant studies. The literature search was performed by two independent investigators . Publication date, language, full article, or abstract was not restricted in our search. The reference lists of eligible studies were manually searched as a complement to electronic search. The results of search were crosschecked, and final consensus was reached between the two investigators.Studies in our meta-analysis had to meet all of the following criteria: (1) case-control design; (2) evaluating the association between SNPs miR-499 T>C (rs3746444) and/or miR-34b/c T>C (rs4938723) and susceptibility to HCC; (3) being studied on human beings; (4) sufficient data of allele and genotype frequencies of SNPs being provided for the estimation of odds ratios (ORs) and 95% confidence intervals (95% CIs); (5) only the most recent study being included if serial studies of the same population were reported; and (6) methodological design being proper. Methodology of potential relevant case-control studies was evaluated using the following criteria: (1) the demographic data were comparable between case and control groups; (2) the diagnosis of HCC was determined with proper diagnostic methods; (3) appropriate methods were employed to determine genotypes; and (4) proper statistical methods were used. The details of study search and selection were provided in  Data were extracted from eligible studies by two independent investigators (Zhongxia Wang and Junhua Wu). The extracted data included the authors' name, publication date, origin of the study, ethnicity of studied population, methods of genotyping, allele, and genotype frequencies in both case and control groups. The two investigators crosschecked the results of data abstraction. When different results were obtained, they repeated data extraction of the specific study and discussed them to reach mutual agreement. If disagreement still existed, two senior investigators (Yitao Ding and Chunping Jiang) were invited to discussion until consensus was reached.Q-test and P > 0.10 indicated that no significant statistical heterogeneity existed [Z-test. A P value less than 0.05 was considered as statistically significant. Corresponding forest plots were generated to show the results of meta-analyses. Chi-square test was used to test whether the distribution of genotypes in control group deviated from HWE. ORs and corresponding 95% CIs were calculated to evaluate the strength of associations between SNPs and the risk of HCC under the following genetic models: (1) allele frequency (C versus T); (2) heterozygous model (TC versus TT); (3) homozygous model (CC versus TT); (4) dominant model (TC + CC versus TT); and (5) recessive model (CC versus TT + TC). Heterogeneity among included studies was evaluated by Cochrane  existed . Pooled  existed . Otherwi existed . The sigSensitivity analysis was conducted by excluding individual study in turn to observe the change in heterogeneity test and the significance of pooled ORs. For miR-499 T>C (rs3746444), subgroup analysis was carried out using data from Asian ethnicity, HBV-infected cases and studies within HWE. All of the data synthesis and statistical analysis were performed using Review Manager 5.2.5 software .As shown in Characteristics of included studies are shown in Q-test became negative after the exclusion of this study. However, there was still no obvious association between rs3746444 and susceptibility to HCC in the remaining studies with less heterogeneity. The association between rs3746444 and the risk of HCC was analyzed using data from five independent studies –21. The  Subgroup analyses were conducted in Asians, HBV infected HCC patients and in studies that conformed to HWE. Similarly, miR-499 T>C rs3746444 was not associated with HCC susceptibility in all genetic model analyzed in Asians. Four studies provided genotypes in HBV-associated HCC patients –19, 21. P = 0.04). In heterozygous model, carriers of TC genotype were more susceptible to HCC compared with TT carriers . A trend of association was also observed in dominant model although it did not reach statistical significance with a marginal P value of 0.06 . No significant association was demonstrated in homozygous model and recessive model. Three studies reported potential association between rs4938723 and HCC risk with evidence from 1672 cases and 1749 controls –24. All  Despite significant advancements in the research of HCC, the detailed etiology of this fatal disease remains elusive. Besides well-known risk factors, such as viral hepatitis, alcohol abuse, and nonalcoholic fatty liver disease (NAFLD), genetic factors may also contribute to the development of HCC , 28. Ide miR-499 participates in several crucial cancer-related biology processes such as apoptosis, cell migration, cell senescence, and inflammation –34. Regu In this meta-analysis, we assessed possible association between SNP rs3746444 and susceptibility to HCC with evidence from 852 cases and 1191 controls. Our results elucidated that there lacks any association between rs3746444 and the risk of HCC in all of genetic models tested. Sensitivity analysis revealed that the study from Xiang et al. [ As members of the miR-34 family, miR-34b and miR-34c share a common primary transcript (pri-miR-34b/c). Induced by p53 in response to genotoxic stress, miR-34b/c are considered as tumor-suppressor miRNAs , 38. PreP value of 0.06. Importantly, obvious heterogeneity existed in the estimation of dominant model. However, limited number of eligible studies and lack of detailed information prevented us from exploring the source heterogeneity by subgroup analysis. Possible association between rs4938723 and the risk of HCC under dominant model should not be rule out. In the present study, we systematically evaluated the potential association of rs4938723 with susceptibility to HCC with data from 1672 cases and 1749 controls. Statistically significant associations were demonstrated in analyses under allele frequency (C versus T) and heterozygous model (TC versus TT). Genetic variant T>C increases the risk of HCC in these two genetic models. A trend of elevated risk of HCC was observed in dominant model (TC + CC versus TT) although this trend did not reach statistical significance with a marginal  To the best of our knowledge, this is the first meta-analysis evaluating the association between miR-34b/c T>C rs4938723 and susceptibility to HCC. This is also the latest study assessing potential association between miR-499 T>C rs3746444 and HCC risk with the most evidence, though the conclusion was in agreement with previous meta-analyses . However In conclusion, the SNP rs4938723 in the promoter region of pri-miR-34b/c gene is associated with elevated susceptibility to HCC. However, our meta-analysis does not support association between rs3746444 and the risk of HCC. Further well-designed studies with larger sample size are required to verify our findings. Functional studies and interactions of these two SNPs with other predisposing or protective factors of HCC will be of great interest. The value of SNP rs4938723 as a genetic biomarker for early diagnosis or a molecular target for novel therapy of HCC is also worthy of investigating.


Cholesteryl ester transfer protein (CETP) plays a major role in lipid metabolism, but studies on the association of CETP polymorphisms with risks of cardiovascular disease are inconsistent. This study investigated whether the CETP gene I405V and Taq1B polymorphisms modified subclinical atherosclerosis in an asymptomatic Brazilian population sample.The polymorphisms were analyzed using polymerase chain reaction in 207 adult volunteers. Serum lipid profiles, oxLDL Ab titers, C-reactive protein and tumor necrosis factor-α concentrations and CETP and phospholipid transfer protein (PLTP) activities were determined, and common carotid artery intima-media thickness (cIMT) was measured using ultrasonography.th percentile and positively interacted with age. However, no associations with the V allele or CETP and PLTP activities were observed.No differences in cIMT were observed between the presence or absence of the minor B2 and V alleles in either polymorphism. However, inverse correlations between mean cIMT and CETP activity in the presence of these polymorphisms were observed, and positive correlations of these polymorphisms with PLTP activity and oxLDL Ab titers were identified. Moreover, logistic multivariate analysis revealed that the presence of the B2 allele was associated with a 5.1-fold  increased risk for cIMT, which was equal and above the 66None of the studied parameters, including CETP activity, explained the different relationships between these polymorphisms and cIMT, suggesting that other non-determined factors were affected by the genotypes and related to carotid atherosclerotic disease. Atherosclerotic disease is a complex multifactorial process that leads to the deposition and accumulation of cholesterol along the arterial wall. CholestThe I405V (rs5882) and Taq1B (rs708272) polymorphisms and their respective minor alleles, V and B2, are associated with decreased CETP activity and increased high-density lipoprotein cholesterol (HDL-C) levels[Therefore, this study investigated whether I405V and Taq1B polymorphisms modified subclinical atherosclerosis in an asymptomatic Brazilian adult sample population.A total of 207 asymptomatic volunteers of both sexes (20–75 years) were recruited at the Lipid Outpatient Clinic at the State University (Unicamp) Hospital in Campinas, SP, Brazil.2; a diagnosis of endocrinological, liver or kidney disease; use of drugs that alter the lipid profile; excessive use of alcohol (>75 g/day)[The following exclusion criteria were used: body mass index (BMI) ≥ 30 kg/m5 g/day); meetingThe local Medical School Ethics Committee approved this study, and all participants signed an informed consent form.The following blood measurements were performed using Roche Diagnostics  reagents in an automated system: total cholesterol (CHOD-PAP), triglycerides , HDL-C (HDL-C plus 3rd generation), low-density lipoprotein cholesterol . Apolipoproteins AI (NAS-ApoA1), B100 (NAS-ApoB) and lipoprotein (a) were obtained from Siemens (USA). C-reactive protein (CRP) was measured using the Tina-quant® CRP (latex) high sensitivity assay . Plasma levels of tumor necrosis factor α (TNF-α) were measured using ELISA .2 and HDL3 sub-fractions were obtained using sequential micro-ultracentrifugation[HDLfugation.CETP and phosAntibodies against oxidized LDL (oxLDL Ab) titers were determined using an in-house ELISA.Genomic DNA was extracted and amplA single trained sonographer, who was blind to the subject’s identity, performed high-resolution B-mode common carotid ultrasonography using a 6–9 MHz linear array ultrasound imaging system . Longitudinal measurements of segments of the common carotid arteries at the distal wall and 1 cm from the bifurcation were performed according to a standardized method. The meath percentile values of the studied population.Mann–Whitney U and Chi-Squared tests compared variables, and the Spearman test was performed for correlations. Univariate and multivariate logistic regression analyses, with stepwise criteria of the variables of interest, the presence of the V and B2 allele, gender, age, HDL-C, BMI and systolic blood pressure (SBP), were performed to verify the relationships of these variables with higher cIMT values, which was defined as above or below the established cutoff value of 0.795 mm and corresponding to cIMT equal and above the 66© was used for the linkage disequilibrium (LD) analysis[All the analyses were performed using the SAS®, version 9.1.3 and SPSS 11.5 for Windows. Haploview, v 4.2analysis.The frequencies of I405V and Taq1B genotypes in our population sample, represented by the presence  and absence (II) of the V allele and the presence  and absence (B1B1) of the B2 allele, are presented in Table Allele frequencies were consistent with Hardy–Weinberg equilibrium for the I405V polymorphism (p=0.36) but not the Taq1B (p=0.02), and the MAFs  were <45% and <46%, respectively. The linkage disequilibrium between the two polymorphisms was very weak, as evidenced by the D`=0.17.Clinical and anthropometric characteristics and biochemical data of the investigated population are presented in Tables Table p value ≤0.05) with higher cIMT.The univariate analyses Table  indicateThe multivariate analysis Table  demonstrA Chi-Square analysis indicated an interaction between the presence of the B2 allele and age. The combination between age, categorized in ≥ and <50 years , and the presence or absence B2 allele formed 4 groups of individuals who were crossed with cIMTs above and below 0.795 mm (data not shown).This study investigated whether the I405V and Taq1B polymorphisms modify subclinical atherosclerosis in an asymptomatic population sample.Previous studies present controversial data on the role of Taq1B and I405V in atherosclerosis and CVD. The B2 allele is associated with lower internal carotid artery IMT in men, but othWe identified positive correlations between cIMT and PLTP and oxLDL Ab in the presence of the V and B2 alleles. Previous studies have suggested that PLTP increases the risk of cardiovascular disease in humans, and the2-C (13%) concentrations. Patients with coronary disease typically exhibit fewer large HDL particles (HDL2), and the concentration of these large particles is a better predictor of future cardiovascular events than HDL-C concentration[The presence of the V allele was associated with lower CETP (24%) and PLTP (29%) activities and higher HDLntration.Lipoprotein (a) plasma levels were also significantly increased in the presence of the B2 allele. High levels of lipoprotein (a) are significantly associated with the presence, severity and extent of carotid atherosclerosis, but thiNo significant differences in CETP activity and HDL-C levels were observed in Taq1B polymorphism, despite a 15.4% reduction in CETP activity in presence of the B2 allele. These results are consistent with a previous study in another Brazilian population, in which no association between Taq1B genotypes and HDL-C levels was observed.A univariate analysis Table  followedth percentile (0.795mm), CETP and PLTP plasma activities and the potential confounding factors, including gender, age, BMI, SBP and HDL-C. Only age exhibited a significant statistical association , which was a strong determinant of cIMT (data not shown). The absence of interactions of other tested parameters with higher cIMT in this study suggests that other non-determined factors were affected by the genotypes and related to carotid atherosclerotic disease.The effects of the Taq1B variant on circulating plasma lipids may be related to other functional mutations within the CETP gene locus that are in LD, which mOur results focused on several biomarkers that were assessed for the first time in the Brazilian population, and the results were partially based on the correlations between a relatively small numbers of individuals. These results merit further exploration due to the high frequency of the investigated polymorphisms in the present Brazilian sample. Identifying the impact of these polymorphisms is an ongoing aim of our research group.The I405V and Taq1B polymorphisms were differently associated with subclinical atherosclerosis because only the presence of the minor B2 allele, but not the V allele, was independently associated with higher cIMT. We demonstrated that none of the studied parameters explained the different relationships between these polymorphisms and cIMT, which leads us to speculate that the association between the B2 allele and cIMT is due to other non-studied factors. Ongoing studies are underway in our laboratory to determine the modulation factors that are involved.CETP: Cholesteryl Ester Transfer Protein; HDL-C: High-Density Lipoproteins Cholesterol; CVD: Cardiovascular Disease; BMI: Body Mass Index; TG: TriGlycerides; LDL-C: Low-Density Lipoprotein Cholesterol; Apo: Apolipoprotein; CRP: C-Reactive Protein; TNF-α: Tumor Necrosis Factor-α; PLTP: Phospholipid Transfer Protein; oxLDL Ab: Antibodies titers against oxidized LDL; cIMT: common Carotid Artery Intima-Media Thickness; SBP: Systolic Blood Pressure; LD: Linkage Disequilibrium; MAF: Minor Allele Frequency.Eliane Soler Parra and Natália Baratella Panzoldo contributed equally to this manuscript.The authors state that they have no conflicts of interest.ESP worked hard on the data analysis, manuscript preparation, and editing. NBP wrote and reviewed the final manuscript. DK participated in the selection of participants, collection of all clinical and laboratory data and clinical examinations. HCFO and JES assisted in the execution of the experimental protocol for the polymorphism detection. LSFC and ACS performed additional statistical analyses and critical discussion. MG conducted the immunological experiments. RTN performed the carotid ultrasonography. VHSZ, ERN and ECRQ critically revised all text and complemented the discussion. ECF designed the study, implemented the clinical arm and coordinated the work. All authors read an approved the manuscript.


C comparison . The subgroup analyses based on ethnicity, source of controls and Hardy-Weinberg equilibrium (HWE) also revealed no such association. There existed a weak publication bias (Egger’s test P=0.02). In conclusion, based on the currently available evidence, there is no association between IL-1α −899 (+4845) C→T polymorphism and susceptibility to AgP.A number of published studies investigated the association between interleukin-1α (IL-1α) −899 (+4845) C→T polymorphism and susceptibility to aggressive periodontitis (AgP). However, the results from different studies are controversial. This study was conducted to further investigate the association between IL-1α −899 (+4845) C→T polymorphism and AgP using a meta-analysis. A search was conducted through PubMed up to May 1, 2013 and a total of 19 relevant case-control studies were identified. The results of this meta-analysis demonstrated that IL-1α −899 (+4845) C→T polymorphism is not associated with susceptibility to AgP under allele T vs. C [odds ratio (OR)=1.00, 95% confidence interval (CI): 0.88–1.14, P=0.98; I Periodontitis is an inflammatory disease of the supporting tissues of the teeth  and is cet al (Various candidate genes have been investigated for association with AgP and polymorphisms in the interleukin-1α (IL-1α) gene were suggested to affect the transcription of IL-1α, with −899 (+4845) C→T identified as one of the relevant polymorphisms. Walker et al  first reThe inclusion criteria were as follows: i) studies that investigated the association between the IL-1α −899 (+4845) C→T polymorphism and susceptibility to AgP; ii) the study design was case-control and the diagnostic criteria of AgP were clearly reported; iii) the AgP patients were free of any other systemic disease and the control subjects were healthy or periodontitis-free; iv) the studies reported the odds ratios (ORs) and associated 95% confidence intervals (CIs) or the number of individual genotypes in the case and control groups, or the data required for their calculation; and v) the publication language was English or Chinese.This meta-analysis was conducted in concordance with the Meta-analysis Of Observational Studies in Epidemiology (MOOSE) guidelines .The search terms ‘polymorphism’ or ‘mutation’ or ‘variant’, ‘interleukin-1’ or ‘IL-1’ and ‘periodontitis’ or ‘periodontal disease’ were used to conduct a search through PubMed up to May 1, 2013. The reference lists of the included studies and recent reviews were manually searched to identify additional relevant studies.According to the prespecified selection criteria, two authors independently selected the studies and extracted the following data: surname of first author, year of publication, country of origin and ethnicity, source of controls, number and genotyping distribution of cases and controls, OR and its 95% CI, genotyping method and Hardy-Weinberg equilibrium (HWE) for controls. Any disagreements were resolved by consulting a third author.2 statistics  C→T polymorphism and susceptibility to AgP  is less prevalent, but is associated with more rapid bone destruction at a relatively young age and is therefore termed ‘AgP’ . Unlike To further investigate the association between IL-1α −899 (+4845) C→T polymorphism and susceptibility to AgP, subgroup analyses by ethnicity, source of controls and HWE were performed. All the results were consistent with those of the overall analysis, indicating no role for ethnic background or environment. Therefore, AgP is likely a genetically inherited disease . Although this may be attributed to the low prevalence of AgP, a small sample size is associated with the possibility of bias. Second, despite thorough attempts to collect relevant studies, publication bias also existed. This may result from the language limitation to English and Chinese, or from negative results not being published. Third, due to the lack of data on origin in the included studies, we were unable to assess the gene-environment interactions, which may affect the susceptibility to AgP. Finally, the negative association between IL-1α −899 (+4845) C→T polymorphism and susceptibility to AgP should be interpreted with caution.In conclusion, our meta-analysis, based on a total of 1,266 AgP patients and 2,134 healthy controls, demonstrated that the IL-1α −899 (+4845) C→T polymorphism is not associated with the risk of AgP. However, due to the abovementioned limitations of the present study, our results may be considered as inconclusive.


The association between polymorphism 4b/a, T-786C and G894T in endothelial NO synthase gene (eNOS) and ischemic stroke (IS) remains controversial in Asian. A meta-analysis was performed to better clarify the association between eNOS gene and IS risk.2. Meta-regression was used to explore the potential sources of between-study heterogeneity. Begg's test was used to estimate publication bias.Based on the search of PubMed, Web of Science (ISI), CNKI , Wan Fang Med Online and CBM  databases, all eligible case-control or cohort studies were identified. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) from fixed and random effect models were calculated. Heterogeneity among studies was evaluated using the IOur study included 27 articles, contained 28 independent case–control studies, involved a total of 3,742 cases and 3,691 controls about 4b/a, 1,800 cases and 1,751 controls about T-786C and 2,747 cases and 2,872 controls about G894T. A significant association of 4a allele with increased risk of IS was found in dominant , recessive  and codominant  models. For T-786C and G894T, there were significant associations with dominant and codominant genetic models, but not with recessive genetic model.The meta-analysis indicated that eNOS gene 4b/a, T-786C, G894T polymorphism might be associated with IS. Stroke is a major cause of morbidity and mortality worldwide Large epidemiological studies have shown that stroke has a genetic predisposition. Duggirala et al. thought that the proportion of genetic factors in the occurrence of stroke was about 66.0%–74.9% The gene encoding eNOS is located on chromosome 7 (7q35–q36), spanning 21 kb and comprising 26 exons The available articles published in English or Chinese  were identified by extended computer-based searches from the following databases: (1) PubMed; (2) Web of Science; (3) CNKI ; (4) Wan Fang Med Online and (5) CBM . The following keywords were used:  and (‘polymorphism’ or ‘mutation’ or ‘genes’) and (‘4b/a’or ‘T-786C’or ‘G894T’) and (‘ischemic stroke’ or ‘stroke’ or ‘brain infarction’ or ‘brain ischemia’ or ‘cerebrovascular disease’). We also reviewed the references cited in the studies and review articles to identify additional studies not captured by our database searches.The inclusion criteria were as follows: (1) case-control or cohort study published as original study to evaluate the association between  polymorphisms in eNOS gene and risk of IS in Asian; (2) Neuroimaging (computed tomography (CT) or magnetic resonance imaging (MRI)) was used to confirm the diagnosis of IS; (3) numbers were reported in case and control groups for case-control studies, or exposed and unexposed groups for cohort studies for each genotype, or data provided from which numbers could be calculated; (4) subjects in each study should come from the same ethnicity and period; (5)Subjects>18 years age. The most recent and complete articles were chosen if one data from the same population had been published more than once. Two investigators carefully reviewed all identified studies independently to determine whether an individual study was eligible for inclusion criteria in this meta-analysis.Two investigators collected the data independently and reached a consensus on all items. The following basic information was extracted from the eligible studies: first author, journal, year of publication, country, ethnicity of studied population, sample size, mean age, male sex percentage, and distributions of allele and genotype. When it came to conflicting evaluations, it was resolved by the third reviewer.2 analysis with exact probability, (HWE: P >0.05). ORs with 95%CI was used to assess the strength of the association of the 4b/a, T-786C and G894T polymorphisms in eNOS gene with risk of IS. We conducted analysis for three polymorphisms considering dominant (aa + ba vs. bb), (CC + TC vs. TT), (TT + GT vs. GG); recessive (aa vs. ba + bb), (CC vs. TC+ TT), (TT vs. GT + GG) and codominant (a vs. b), (C vs. T), (T vs. G) models for 4b/a, T-786C and G894T respectively. I2 of Higgins and Thompson 2>50%) Departure from Hardy–Weinberg equilibrium (HWE) for the 4b/a, T-786C and G894T genotype distribution of eNOS gene in controls was tested by χWe identified 27 articles The results of the pooled analysis are summarized in For 4b/a polymorphism, overall, significant association was found between the 4a allele and IS risk in dominant , recessive  and codominant  models. In subgroup analysis, for Chinese population, the 4a allele was found contributing significantly to increased IS risk in dominant , recessive  and codominant  models. All the associations were not altered significantly after excluding articles For T-786C polymorphism, this meta-analysis showed a significant protective effect of the C allele on IS risk in dominant , codominant  models, but not in recessive  model. In subgroup analysis by country, no significant association was found in any of the above-mentioned inherited models for Chinese population. All included articles were in HWE in controls for T-786C. For G894T polymorphism, overall, significant association was found between T allele and IS risk in dominant  and codominant  models, but not in recessive  model. And subgroup analysis, for Chinese population, significant association was found in dominant  and codominant  models, but not in recessive  model. All included articles were in HWE in controls. For IS risk in overall, after exclusion of articles with OR>3.0 If the frequency of mutation homozygous were 0 in case group, it was not sufficient to calculate pooled OR for recessive model. For this reason, in T-786C polymorphism, two articles After excluding articles for OR>3.0 2>50%) was found in the codominant model considering the association of 4b/a polymorphism with IS risk; T-786C polymorphism in recessive model and G894T in codominant model, respectively.After exclusion of articles deviating from HWE in controls, evidence for heterogeneity .Begg's test was used to assess the publication bias. After exclusion of articles deviating from HWE in controls and sensitivity analysis, no significant publication bias was detected in any of the above-mentioned inherited models considering all the polymorphisms except the recessive model in G894T polymorphism (data not shown).Ischemic stroke is known to be a multifactorial disorder. In addition to the commonly accepted risk factors, there is increasing evidence for the role of genes in the pathophysiology of ischemic stroke Recently, studies have been performed to evaluate the correlation between eNOS gene  polymorphisms and the risk of IS. However, the results remained controversial. Since an individual study has a relatively small number of participants with low power to detect the effect, a meta-analysis may be the appropriate approach to obtain a more definitive conclusion. In this meta-analysis, we summarize the results of 27 case-control articles with 28 eligible outcomes published so far on the association between eNOS gene  polymorphisms and IS risk. A significant association of 4a allele with increased risk of IS was found in dominant, recessive and codominant models. For T-786C and G894T, there were significant associations with dominant and codominant genetic models, but not with recessive genetic model. In the subgroups, for Chinese population, the results were consistent with overall results. The results of our study were contrary with the previous meta-analysis in 2009 For a simple genetic variant with two alleles, the classical models of inheritance  are typically assumed for complex traits when the inheritance model is unknown Between-study heterogeneity is common in meta-analysis for genetic association studies In this meta-analysis, no significant publication bias for 4b/a, G894T polymorphisms in any of the above-mentioned inherited models, suggesting the associations observed should be stable.In conclusion, our meta-analysis suggested that eNOS gene 4b/a, T-786C, G894T polymorphism might be associated with IS. This conclusion highlighted the importance of the eNOS gene on IS in Asian which might be a useful suggestion for clinical therapeutic intervention. The present study is limited by we could not completely preclude the potential biases and confounders in meta-analysis. Further research is warranted to confirm our findings.Table S1Details of reasons for exclusion of studies from meta-analysis.(DOC)Click here for additional data file.Table S2PRISMA checklist.(DOC)Click here for additional data file.


TLR4 gene have been associated with RSV infection in children. However, it is unclear to what extent this association is confounded by BPD or prematurity. In this study, we analyzed two population-based cohorts of preterm infants at risk for BPD as well as ethnicity-matched infants born at term, to test whether the TLR4 polymorphisms Asp299Gly (rs4986790) and Thr399Ile (rs4986791) are independently associated with BPD or premature birth. In a Canadian cohort (n = 269) composed of a majority of Caucasian preterm infants (BPD incidence of 38%), the TLR4-299 heterozygous genotype was significantly under-represented in infants without BPD (1.6% of infants versus 12% in infants with severe BPD) after adjusting for twins, ethnicity, gestational age, birth weight and gender (p = 0.014). This association was not replicated in a Finnish cohort (n = 434) of premature singletons or first-born siblings of Caucasian descent, although the incidence of BPD was substantially lower in this latter population (15%). We did not detect a significant association (>2-fold) between TLR4 genotypes and prematurity (p>0.05). We conclude that these TLR4 genotypes may have, at best, a modest influence on BPD severity in some populations of high-risk preterm infants. Further studies are warranted to clarify how clinical heterogeneity may impact genetic susceptibility to BPD.Bronchopulmonary dysplasia (BPD) is a common chronic lung disease and major risk factor for severe respiratory syncytial virus (RSV) infection among preterm infants. The Toll-like receptor 4 (TLR4) is involved in oxidative injury responses in the lungs. Two non-synonymous single nucleotide polymorphisms in the  Bronchopulmonary dysplasia (BPD) is a serious chronic inflammatory lung disease frequently observed in premature infants born at less than 32 weeks of gestation (TLR4) gene has been directly implicated in the immune response against RSV TLR4 gene (referred to as Asp299Gly and Thr399Ile based on the amino acid permutations they encode) are in strong linkage disequilibrium and potentially impact function of the receptor TLR4-299/-399 genotypes was substantially greater (89.5%) compared to literature controls (∼10.5%) TLR4 genotypes (16% and 17%) in relation with severe RSV infection or no significant increase at all TLR4-299/-399 genotypes and BPD, or even prematurity.Genetic factors likely play an important role in determining susceptibility to respiratory disease such as BPD or RSV TLR4 gene is also consistent with an emerging appreciation of the role of TLR4 in protecting lung tissue against oxidative damage . Of these infants, 65% were of Caucasian origin  compared to infants without BPD . The frequency of combined heterozygous/rare homozygous TLR4-299 genotype was greater in preterm neonates with moderate or severe BPD (n = 103) compared to preterm neonates without BPD (n = 62) used as a control group . Only one preterm neonate was homozygous for the rare TLR4-299 allele; this infant had severe BPD and required prolonged mechanical ventilation for over 45 days. Altogether, these data indicate a potential genetic association between the two TLR4-299 and −399 genotypes and BPD severity.In preterm cohort A, a majority of TLR4 genotypes and BPD severity remained significant after adjusting for twins, gestational age, birth weight, gender, Caucasian origin and recruitment centre .The association between the TLR4-299 and −399 genotypes and BPD severity . The incidence of infants with BPD requiring supplemental oxygen at 36 weeks PMA was generally low (15%). In these infants, the proportions of genotypes in infants with or without BPD were similar and we did not detect a similar association between either severity Table 5.TLR4 genotypes and prematurity in preterm cohort A, infants were compared to a control group of term-born neonates matched by self-declared maternal ethnicity. As expected, both TLR4-299 and −399 heterozygous variants highly co-segregated (>99% of cases) in neonates from both cohorts (data not shown). The overall frequencies of the heterozygous TLR4-299 and −399 genotypes in both term-born cohort  and preterm cohort A  were consistent with frequencies previously reported in healthy children TLR4-299 or −399 genotype frequencies in preterm cohort A and term-born infants (p>0.05). Moreover, in regression analysis we did not detect associations between gestational age, birth weight, gender or ethnicity, and either combined −299- or −399 heterozygous/rare homozygous genotype within the group of preterm neonates (p>0.05).In order to examine potential associations between TLR4 gene polymorphisms on BPD and prematurity. An influence of TLR4-299/-399 genotypes on BPD severity is highly biologically plausible given the major role of this receptor in lung protection against the effects of hyperoxia and compelling body of evidence indicating that these genotypes may alter TLR4 responsiveness TLR4-299 and −399 genotypes in preterm infants born ≤30 weeks of gestation recruited in a Canadian population of mixed ethnicity. However, this association was not replicated in a second Finnish cohort of singletons or first-born sibling preterm infants born <32 weeks of gestation recruited from a homogenous Caucasian population. In addition, a >2-fold association between extreme prematurity and the two TLR4 polymorphisms was not detected.In this study, we specifically addressed the influence of two common non-synonymous TLR4-299/-399 genotypes appear to have little functional effect on peripheral blood innate immune functions TLR4-299Gly and 399Ile allelic variants additively impair interaction with the co-receptors MD-2 and/or CD14; consistent with our genetic association data the minor −299Gly allele is reported to have a greater functional impact than the minor 399Ile allele TLR4 genotype is more likely to reduce tolerance to excessive oxygen exposure in primary respiratory tissues, therefore predisposing some infants to BPD. Consistent with this mechanism, we found that the combined frequency of the heterozygous and rare homozygous TLR4 genotypes was low in infants without BPD (1.2%) compared to the term-born infants or to previous reports in pediatric cohorts Although TLR4 genetic association with BPD is preserved in our sensitivity analysis of the sub-group of Caucasian in preterm cohort A, lack of power or differences in the ethnic distribution are unlikely to explain the differences in association between preterm cohort A and B. Alternatively, variations in clinical practice , which can be substantial among neonatal centers, may modulate genetic influences on BPD Replication of findings in independent populations is a widely accepted method to exclude false-positive associations in genetic association studies TLR4 genotypes of unusually high magnitude  TLR4 polymorphisms and symptomatic RSV infections exist in children with or without BPD.Awomoyi and colleagues reported an association between RSV and TLR4 variants and prematurity, slight enrichment in heterozygous/rare homozygous TLR4-299 genotype frequencies (from 16 to 23%) has been reported by Lorenz et al. in mid-preterm Finnish infants (i.e. 33±3.5 weeks of gestation) compared to infants born at term. More significant associations have not been detected in African infants born earlier in gestation (<33 weeks) TLR4-299Gly and -399Ile alleles, however, it is important to appreciate that our cohort was not specifically powered to detect the small difference in TLR4-299 genotype frequency reported by Lorenz et al.TLR4-299/-399 polymorphisms and prematurity, of magnitude greater than 2-fold.With regard to a possible modest association between TLR4 on BPD, in some populations of at-risk preterm infants. Further studies are required to substantiate this finding and/or to clarify how variations in clinical practices among neonatal centers may influence genetic effects of TLR4 polymorphisms on BPD severity in preterm infants.In conclusion, our data support a potential modest influence of common non-synonymous variants in the biologically-compelling candidate gene This study was conducted according to the principles expressed in the Declaration of Helsinki. Parental written informed consent was obtained for all subjects recruited in this study. This study was approved by the University of British Columbia Clinical Research Ethics Board, the University of Alberta Ethics Board and the Research Ethics Board of Oulu University Hospital.Preterm cohort A: The first preterm cohort consist of premature neonates of mixed ethnicity  maternal and parental descent sequentially recruited at the University Hospital of Oulu (Finland). These infants represent 80% of all very preterm infants from the district of Northern Finland. In both cohorts, only infants without major congenital anomalies of the cardiorespiratory system in whom written parental consent could be obtained were enrolled. Approximately 62%, 51% and 65% of eligible preterm infants in study period were enrolled at C&W, RAH or Oulu hospitals, respectively. Controls for the preterm cohort A were term-born infants (>37 weeks gestation) sequentially recruited at birth (C&W), from mothers undergoing elective repeat caesarean section deliveries in the context of a healthy pregnancy between February 2006 and August 2007.Standard outcome measures that were the same between the two populations were used to limit the possibility of misclassification. BPD was defined as a chronic need for supplemental oxygen at 36 weeks of post-menstrual age (PMA) or at time of discharge home whichever came first, and further graded by severity using criteria adapted from the National Institute of Child Health and Human Development (NICHD) TLR4-299 (reference dbSNP: rs4986790) and −399 (reference dbSNP: rs4986791) allelic variants was performed by real time quantitative PCR as previously described DNA was either obtained from cord blood, umbilical cord tissue or peripheral blood depending on the circumstances of enrolment. DNA extraction was carried out using the ChargeSwitch gDNA Mini Tissue kit (Invitrogen) or the QIAamp DNA Blood Midi kit (QIAgen). Genotyping of TLR4-299/-399 variants and BPD, we estimated that 200 preterm neonates in cohort A (estimated incidence of BPD of 35%) and 350 preterm neonates in cohort B (due to a lower estimated incidence of BPD of 20%) would be sufficient considering the ∼10% baseline TLR4 genotype frequencies reported in the general population . Similarly, we estimated that 200 term-born control neonates would allow us to detect at least a 2-fold difference in heterozygous allele frequencies between preterm and term-born infants. To detect an association with prematurity in preterm cohort A, infants were matched in frequency with term-born neonates according to self-reported maternal ethnicity. The Fisher exact or chi-square probability test were used to determine significance of differences in proportions, allelic or genotype frequency between groups. Multivariate regression analyses were performed using genotype or BPD as the dependant variable and included cited adjustment co-variables. For the preterm cohort A, regression models were also adjusted for twins using a co-variable defining each singleton or twin pair. 95% confidence intervals were calculated using the exact method. Statistics were computed using SPSS version 11.0 for Microsoft Windows.In order to exclude a greater than 2-fold association between


VDR) and aggrecan variable numbers of tandem repeat (VNTR) polymorphisms and the risk of intervertebral disc degeneration (IDD), but produced conflicting results.A series of studies have been conducted to evaluate the associations between vitamin D receptor , FokI (rs2228570), ApaI (rs7975232), or aggrecan VNTR polymorphisms and the risk of IDD, respectively. The combined results showed that none of the VDR  polymorphisms were significantly associated with the risk of IDD. In contrast, the alleles with shorter VNTR length was found to significantly increase the risk of IDD . Subgroup analysis confirmed the above results. After excluding studies deviated from Hardy-Weinberg equilibrium (HWE) in controls, no other studies were found to significantly influence the pooled effects in each genetic model. No potential publication bias was detected.A total of 9, 5, 3, and 7 studies were finally included in the analyses for the associations between the VNTR length significantly increased the risk of IDD, while the VDR  gene polymorphisms were not significantly associated with the risk of IDD. Since potential confounders could not be ruled out completely, further studies are needed to confirm these results.This meta-analysis suggested that the alleles with shorter  Intervertebral disc degeneration (IDD) is a major pathological process implicated in low back pain, and is a prerequisite to disk herniation VDR) gene is the first reported gene potentially associated with IDD risks VDR gene is located on human chromosome 12 (12q12–q14), with a length of 100 kb, and has more than 100 restriction endonuclease cutting site polymorphisms VDR is a member of the steroid superfamily of nuclear receptor, which plays a key role in the regulation of the transcriptional activity of vitamin D metabolite, 1α, 25-dihydroxyvitamin D3 VDR gene polymorphisms are thought to contribute to a variety of disorders including osteoporosis, osteoarthritis, tumor, and cardiovascular diseases VDR gene polymorphisms and the risk of IDD. These studies have mostly focused on a few selected variants, including the TaqI (rs731236), FokI (rs2228570), and ApaI (rs7975232) restriction sites. However, the results have been inconsistent. Some studies suggested that VDR TaqI gene polymorphism was associated with increased risk of IDD Vitamin D receptor (VNTR) polymorphism within the aggrecan CS1 domain VNTR polymorphism and the risk of IDD has been investigated in several recent studies. Kawaguchi et al. firstly reported that subjects with shorter VNTP length of the aggrecan had a risk of having multilevel IDD Aggrecan is a large aggregating proteoglycan which is a functionally important component of intervertebral disc and articular cartilage. Humans are known to uniquely exhibit variable numbers of tandem repeat , Database of Chinese Scientific and Technical Periodicals (VIP), and China Biology Medical literature database (CBM). The search strategy to identify all possible studies involved use of combinations of the following key words: (“vitamin D receptor” or “VDR” or “aggrecan”) and “polymorphism” and “disc degeneration”. The reference lists of review articles, clinical trials, and meta-analyses were also hand-searched for the collection of other relevant studies. If more than one article were published using the same case series, only the study with largest sample size was selected. The literature search was updated on May 1, 2012.VDR  polymorphisms or aggrecan VNTR polymorphism and the risk of IDD; (2) case-control or cohort design; (3) providing sufficient data for calculation of odds ratio (OR) with the corresponding 95% confidence interval (95%CI). When genotype frequencies and OR with 95%CI were all not available, authors were contacted to request the relevant information. All identified studies were carefully reviewed independently by two investigators to determine whether an individual study was eligible for inclusion in this meta-analysis.The studies included must meet the following criteria: (1) evaluating the associations between Data were extracted independently by two investigators who reached a consensus on all of the items. The following information was extracted from each study: (1) name of the first author; (2) year of publication; (3) country of origin; (4) ethnicity of the study population; (5) source of control subjects; (6) numbers of cases and controls; (7) gender and age of enrolled subjects; and (8) numbers of genotypes in cases and controls.Z test. Heterogeneity among studies was assessed using Q test as well as the 2I statistic, which was documented for the percentage of the observed between-study variability due to heterogeneity rather than chance 2I>50%, otherwise, the Mantel-Haenszel fixed effect model (FEM) was considered to be the appropriate choice I2 statistic. Data analysis was performed using STATA version 11 .We use χ2 analysis with exact probability to test departure from Hardy-Weinberg equilibrium (HWE) for the genotype distribution. The associations of four gene polymorphisms with IDD were estimated by calculating pooled ORs and 95%CI. The significance of the pooled effect size was determined by VDR or aggrecan VNTR polymorphisms and IDD risks were identified. Of these, 25 studies were excluded by reading titles and abstracts. One study investigated other aggrecan polymorphisms rather than VNTRVDR TaqI, FokI, ApaI or aggrecan VNTR polymorphisms and the risk of IDD, respectively. For the VDR TaqI, FokI, or ApaI polymorphisms, 5, 1, and 3 studies examined individuals of Asian descent, while the remaining studies recruited Caucasians. For the aggrecan polymorphism, 4 and 3 studies were on Caucasians and Asians, respectively. All the included studies used blood samples for DNA extraction. Magnetic resonance images (MRI) was used for the detection of IDD in almost all the studies, while computed tomography (CT) was used in one study VDR TaqI, FokI, or ApaI polymorphisms, genotype distribution in control groups were in HWE except for one study for TaqI polymorphism FokI polymorphism vs. >25; ≦23 vs. >23). The detailed characteristics of the included studies are shown in the  and 47 relevant studies concerning VDR  polymorphisms and the risk of IDD are shown in VDR TaqI polymorphism and the risk of IDD  , and the subgroup analysis further confirmed the irrelevance between the genotypes and the risk of IDD. The results were not altered after excluding the study deviated from HWE, further confirming the null association between VDR TaqI polymorphism and the risk of IDD. However, when we excluded the studies by Chen et al., in which the 95%CI did not overlap the lines of the pooling results, a significant association was found in Asians .Results of pooled analysis on the associations between 3–1.533) Fig. 2. VDR (FokI and ApaI) polymorphisms and the risks of IDD were similar to those of VDR TaqI and IDD risk. Overall, no significant association was found between VDR FokI polymorphism and IDD risk . Similarly, no significant association was found between VDR ApaI polymorphism and IDD risk . As limited studies were included for the above two association investigation, we did not perform subgroup analysis.The pooled results on the associations between VNTR polymorphism and the risk of IDD are shown in VDR polymorphisms and the risk of IDD, a significant association was observed between aggrecan VNTR polymorphism and the risk of IDD. The alleles with shorter VNTR length was found to significantly increase the risk of IDD   as well as in Asians . Subgroup analysis stratified by gender and age also confirmed the above results.Results of pooled analysis on the associations between aggrecan 1–2.703) Fig. 3. After excluding studies that deviated from HWE in controls, and those in which 95%CI did not overlap the lines of the pooling results, no other studies were found to significantly influence the pooled effects in each genetic model. In the cumulative meta-analysis, no particular time trend was found in the summary estimate.VDR  and aggrecan VNTR polymorphisms and the risk of IDD   and aggrecan VNTR polymorphisms and the risks of IDD. In this study, a total of 9, 5, 3, and 7 studies were finally included in the analyses for the association between the VDR TaqI, FokI, ApaI or aggrecan VNTR polymorphisms and the risks of IDD, respectively. The combined results showed that none of the three VDR polymorphisms were significantly associated with the IDD risk. Subgroup analysis stratified by ethnicity, age, and sex, also revealed no association, although a significant association was found in Asians  when excluding one study, in which the 95%CI did not overlap the lines of the pooling results. In contrast, aggrecan VNTR polymorphism was found to be significantly associated with the risk of IDD. The alleles of shorter VNTR length was found to significantly increase the risk of IDD . Subgroup analysis stratified by ethnicity, gender and age also confirmed the above results. After excluding studies that deviated from HWE in controls, no other studies were found to significantly influence the pooled effects in each genetic model. Cumulative meta-analysis showed that no particular time trend existed in the summary estimate. Furthermore, no potential publication bias was detected by funnel plots and Egger's regression test. These data indicated the robustness of the summary estimate derived from this study.To the best of our knowledge, this is the first meta-analysis addressing the associations between VNTR, polymorphism in the part of exon 12 encoding the CS1 domain VNTR numbers have the lowest number of CS chains on their aggrecan molecules, and this configuration may result in impaired aggrecan function. Although the association between aggrecan VNTR polymorphism and risk of IDD was not found in some studies VNTR repeats were overexpressed in IDD patient than control subjects. As no studies provided the genotypes of each participant, thus we did not compare the distribution of genotypes between case and control groups.Aggrecan is the major proteoglycan of the disk, which is responsible for maintaining tissue hydration through the osmotic pressure provided by its constituent chondroitin (CS) and keratin sulfate chasins (KS) VDR is a steroid nuclear receptor, better known to have an important role in normal bone mineralization and remodeling. VDR expression was reported in chondrocytes and is thought to be involved in differentiation, proliferation, and maturation of cartilage VDR gene could influence the stability of the mRNA and vitamin D expression VDR polymorphisms were associated with the risks of IDD, the current meta-analysis did not find any significant association between the three polymorphisms, FokI (rs2228570), TaqI (rs731236), and ApaI (rs7975232), and the IDD risks. However, after scrutiny of the included studies, we could find that most of the studies included for the analysis of aggrecan gene recruited subjects in the absence of other risk factors such as obesity, smoking, heavy physical occupations VDR gene polymorphisms. Thus, it could be speculated that the potential association between VDR polymorphisms and IDD may be obscured by some environmental factors. Furthermore, VDR polymorphisms have been reported to be significantly associated with the multilevel and severe forms of IDD VDR gene polymorphisms and the risks of IDD could not be excluded.Despite the clear strengths of our study such as the larger sample size comparing with the previous individual ones, it does have some limitations. First, the present meta-analysis was based primarily on unadjusted effect estimates and CIs , thus the effect estimates were relatively imprecise. If individual data were available, adjusted ORs could be obtained to give a more precise analysis. Second, it has been well known that IDD is a multifactor disease, however, the effects of gene-gene and gene-environment interactions were not addressed in this meta-analysis, and thus the potential roles of the above gene polymorphisms may be masked or magnified by other gene-gene/gene-environment interactions. Thirdly, although the funnel plot and Egger's test showed no publication bias, selection bias may also exist because only published studies in English or Chinese were retrieved.VDR  and aggrecan VNTR polymorphisms and the risks of IDD. The combined results clearly showed that the alleles with shorter VNTR length significantly increased the risk of IDD in Caucasians as well as in Asians. In contrast, none of the VDR  gene polymorphisms were significantly associated with the development of IDD. Since potential confounders could not be ruled out completely, further studies are needed to confirm these results.In summary, the current meta-analysis systematically analyzed the associations between PRISMA Checklist S1PRISMA Checklist.(DOC)Click here for additional data file.


MTHFR) variants, C677T and A1298C, have been reported to be associated with decreased risk of acute lymphoblastic leukemia (ALL). However, results derived from individually underpowered studies are conflicting. We carried out an updated meta-analysis on the association between MTHFR polymorphisms and ALL risk.5,10-methylenetetrahydrofolate reductase . The heterogeneity and publication bias were estimated. Meta-regression analysis was performed to evaluate the potential sources of heterogeneity.Relevant publications were searched through PUBMED and EMBASE databases. The associations between RE = 0.91, 95% CI: 0.83-0.99). Subgroup analysis showed MTHFR C677T variant was associated with decreased susceptibility to ALL in children and Caucasians. Meta-regression showed the logOR for the association between T allele and ALL increased as sex ratio (M/F) in the case group increased (P = 0.01). Regarding A1298C polymorphism, no significant association was observed . There was no publication bias for C677T or A1298C polymorphism.C677T polymorphism was associated with a reduced risk of ALL . Since folate intake may be a possible confounding factor, including this factor in future prospective studies is warranted. Further meta-analysis studies should be at least stratified for folate levels and gender to give more powerful and informative results.The present meta-analysis suggests that the C677T polymorphism, not A1298C, in  Acute lymphoblastic leukemia (ALL) is a malignant neoplasm of the lymphocyte precursor cells or lymphoblasts. This hematologic malignancy accounts for 75% of pediatric leukemias and 20% of adult leukemias, with an early peak incidence at 2 to 5 years of age followed by a second peak after age 50 years-3. To daMTHFR gene, containing 11 exons and 10 introns, is located on the short arm of chromosome 1 (1p36.3) [MTHFR gene, C677T (rs1801133) and A1298C (rs1801131) contribute to reduced enzyme activity and disturbance in folate metabolism. Severe enzymatic activity deficiency results in hyperhomocysteinaemia and is linked to increased risk of neural tube defects and vascular diseases[Folate metabolism plays an essential role in both DNA synthesis and cellular methylation reactions . The enzyme 5,10-methylenetetrahydrofolate reductase (MTHFR) is a key player in folate metabolism, which irreversibly catalyzes the reduction of 5,10-methylenetetrahydrofolate  into 5-methyltetrahydrofolate (5-methyl THF), the predominant circulatory form of folate  and ALL, using the following search terms: methylenetetrahydrofolate reductase or MTHFR; leuk(a)emia, acute lymphocytic or acute lymphoblastic; and gene, polymorphism or genetic variant. The latest searches were undertaken on Oct 3, 2011. All relevant articles identified through the search were scanned on the basis of title and abstract. The articles that clearly did not meet the inclusion criteria were rejected in the initial screening. The appropriateness of remaining articles for inclusion in the meta-analysis was assessed by reading the full text. All references cited in the studies were reviewed to identify additional publications. We also evaluated previous meta-analysis articles [We conducted a comprehensive search of PUBMED and EMBASE databases for publications on the association between articles  and manuThe meta-analysis included case–control, cross-sectional and cohort studies that met all of the inclusion criteria as follows: (i) provided cases of ALL and control subjects without hematologic or other malignancies; (ii) provided relevant data to calculate the odds ratio (OR); (iii) published in English language journals. Case reports, editorials and review articles were excluded. Family-based association studies and genome-wide linkage scans were also excluded for different design considerations. When multiple studies reported on the same population, we used the most recent one only.For each eligible study, the following data were extracted independently by 2 investigators, using a piloted data extraction form: first author, year of publication, demographics , study design, genotyping method, leukemia characteristics, number of case and control subjects, source of controls and blinding of laboratory workers to participant status. The frequencies of the allele and the genotypic distributions were extracted , for both the cases and the controls. When articles presented data for different ethnic groups, results for the subgroups were considered as separate studies. If raw data could not be extracted for the meta-analysis, we attempted to obtain this information by corresponding with the authors. Discrepancies were resolved by discussion, when necessary, adjudicated by a third reviewer.MTHFR C677T and A1298C polymorphisms was evaluated by OR with corresponding 95% confidence intervals (CIs) under allele contrast, dominant model, recessive model and additive model[The risk of ALL associated with the ive model. In addiQ-statistic [P < 0.10, the heterogeneity was considered significant, which was further explored by I2 statistic. I2 is expressed as the percentage of between-study variability that is attributable to genuine variation rather than sample error[The interstudy heterogeneity in terms of degree of association was tested using the Cochran’s tatistic . If P < ple error. If therple error.MTHFR polymorphisms on ALL risk, and year of publication, journal impact factor  might lead to publication bias and heterogeneity, we included these factors as covariates in meta-regression. The cumulative and recursive cumulative meta-analysis were performed to demonstrate how evidence concerning the genetic association has evolved over time [2 test was used to evaluate Hardy-Weinberg equilibrium (HWE) in the control group for all studies. Studies with controls not in HWE or studies not reporting enough information to evaluate HWE were subjected to a sensitivity analysis. Furthermore, we omitted 1 study at a time to assess the stability of results in the sensitivity analysis. Analyses were performed with Stata software , using two-side P-values.Given that immunophenotypic subtypes of ALL (B or T-lineage ALL), sex ratio  might modulate the effects of ver time . The Eggver time . PearsonMTHFR polymorphisms and ALL met the inclusion criteria. Figure The literature search identified 155 articles. After abstract examination, 111 articles were excluded, and 44 articles were retrieved and evaluated against the inclusion criteria. Data from 33 articles-54 that P value (P < 0.05). Thirty-four studies dealt with C677T, 29 studies dealt with A1298C and 28 studies investigated the two polymorphisms together.The studies were published from 1999 through 2010  of T allele/TT genotype in controls in Caucasians was 35.4/12.9, in East Asians was 40.8/16.0, respectively. The studies provided 5356 cases and 9906 controls for A1298C polymorphism. The frequency (%) of C allele/CC genotype in controls in Caucasians was 31.8/10.1, in East Asians was 18.5/3.3, respectively. Detailed information regarding genotype distribution and allele frequency for cases and controls is available in Additional file PQ-Test = 0.13, I2 = 22%). Marginally significant inverse association was observed in allele contrast, recessive model and additive model . Analysis stratified by ethnicity showed 677 T variant was associated with a significantly decreased risk of ALL in Caucasians under all genetic contrasts . However, no significant association was observed in East Asians , which could explain 28% of the variance . The logOR for the association between T allele and ALL increased as M/F in the case group increased. No covariates modulating the effect of A1298C polymorphism on ALL risk was found (data not shown). Cumulative meta-analysis showed a trend of inverse association between C677T variant and ALL risk as evidence accumulated. Recursive cumulative meta-analysis showed that the relative change in ORs for the C677T polymorphism fluctuated in the beginning years (from 1999 to 2006) and then stabilized at around 1.0  in ALL cases and genetic effect , indicating there is no differential magnitude of effect in large vs small studies.No significant publication bias was detected for C677T or A1298C polymorphism by formal statistics . On thee levels , colorece levels  and othee levels ,4. This Our data show that C677T variant plays a protective role in a group of pediatric patients, but has no significantly beneficial effect in adult subjects. There is significant difference between adult and childhood acute leukemia. The most common form of acute leukemia in adults is acute myeloid leukemia (AML), whereas in childhood is ALL. The effMTHFR C677T polymorphism was associated with a significant reduction of ALL risk in Caucasian subjects, whereas it failed to show any protective effect in East Asians. As the role of the MTHFR genotypes in the development of ALL may differ among population origin due to the different dietary customs and racial backgrounds [RE = 0.89, 95% CI: 0.79-0.997, n = 11; East Asian children, ORRE = 0.79, 95% CI: 0.69-0.92, n = 3). As we included English studies only in this meta-analysis, the results might be influenced by language bias, especially in non-English ethnicity. We pooled the studies on Chinese children without any restriction on language in another article and found a significant protective effect of MTHFR C677T variant on ALL risk . We cannot exclude the possibility that the difference between Caucasians and East Asians is attributable to chance factors or age composition. Thus, the conclusion derived from such subgroup should be interpreted with caution.We observed kgrounds , we retrkgrounds . There mkgrounds . TherefoWe carried out the meta-regression study to evaluate the potential sources of heterogeneity. For C677T polymorphism, the heterogeneity could be partly attributed to variation in M/F in ALL cases of the original studies. The OR increased as M/F in the case group increased. It was surprising to find OR > 1 in studies with M/F ≥ 2 in case group, indicating the protective effect of T allele disappeared or even turned to the opposite in these studies ,36,50,51MTHFR genotypes and dietary folate intake has been documented in previous studies concerning colorectal cancer, which might alter the effects of the polymorphic variants [MTHFR polymorphic variants and ALL susceptibility. Conflicting results among studies may be due to the lack of information on folate status. Other enzymes involved in folate metabolism, including methionine synthase (MS), thymidylate synthase (TS) and serine hydroxymethyltransferase (SHMT), may regulate intracellular folate metabolism. The variant forms of these enzymes may be associated with the risk of ALL and interactions between these candidate genes may exist. Three included studies described the interactions between MTHFR polymorphisms and other gene variants. Jonge et al. [MTHFR C677T and NNMT C-151 T variants interacted to decrease the risk of pediatric ALL. Petra et al. [MTHFR C677T, MS A2756G and MTRR A66G interaction was associated with a reduced risk of pediatric ALL, whereas Gemmati et al. [MTHFR C677T and MS A2756G polymorphisms. No further analysis on these interactions in our study was performed due to limited number of reports on each item.Gene-environment interaction between the variants ,6. With variants ,64. As me et al.  found tha et al.  reportedi et al.  did not MTHFR gene is associated with decreased susceptibility to ALL, and indicates a lack of positive relationship between A1298C polymorphism and ALL. The C677T variant plays a protective role in pediatric patients and Caucasian subjects. M/F in cases could modulate the influence of the C677T polymorphism on ALL susceptibility. Although more than 30 genetic association studies are included in this meta-analysis to draw relative safe conclusions, it is also worth mentioning that several interesting but unsolved issues are raised from current meta-analysis and thus further studies are needed which should be at least stratified for folate levels and gender.In conclusion, the present meta-analysis suggests that the C677T polymorphism in The authors declare that they have no competing interests.HGW drafted the manuscript and performed data analysis. JLW edited the manuscript. HGW, JLW and LXZ participated in data collection. XCL and WJM conceived of the study and participated in designing the manuscript. All authors participated in revising the manuscript. All authors have read and approved the final manuscript.The pre-publication history for this paper can be accessed here:http://www.biomedcentral.com/1471-2350/13/77/prepubFigure S1.Folate metabolism and the role of MTHFR. Modified from Wiemels et al. (5).Click here for fileTable S1.General characteristics of studies included in the meta-analysis on MTHFR polymorphisms and ALL risk.Click here for fileTable S2.MTHFRC677T genotype distribution and allele frequency in ALL cases and controls.Click here for fileTable S3.MTHFRA1298C genotype distribution and allele frequency in ALL cases and controls.Click here for fileFigure S2.Sensitive analysis to assess the influence of a single study in the meta-analysis on MTHFR C677T polymorphism and the risk of ALL. Allele contrast was used in sensitive analysis. N, non-Caucasians, admixture of Amerindians, Europeans and Africans; W, mainly Brazilians of Caucasian descent.Click here for fileFigure S3.Sensitive analysis to assess the influence of a single study in the meta-analysis on MTHFR A1298C polymorphism and the risk of ALL. Allele contrast was used in sensitive analysis. C, Chinese; M, Malays; N, non-Caucasians, admixture of Amerindians, Europeans and Africans; W, mainly Brazilians of Caucasian descent.Click here for fileTable S4.Results of the pooled OR and the corresponding 95% CIs for each combined genotype for MTHFR C677T and A1298C polymorphisms.Click here for fileTable S5.Characteristics of meta-analyses regarding MTHFR polymorphisms and ALL risk. (DOC 42 kb)Click here for file


MUTYH are responsible for MUTYH-associated polyposis and CRC predisposition as an autosomal recessive trait. Numerous reports have suggested MUTYH mono-allelic variants to be low penetrance risk alleles. We report a large collaborative meta-analysis to assess and refine CRC risk estimates associated with bi-allelic and mono-allelic MUTYH variants and investigate age and sex influence on risk.Defective DNA repair has a causal role in hereditary colorectal cancer (CRC). Defects in the base excision repair gene MUTYH genotype data were included from 20 565 cases and 15 524 controls. Three logistic regression models were tested: a crude model; adjusted for age and sex; adjusted for age, sex and study.MUTYH bi-allelic carriers demonstrated a 28-fold increase in risk : 6.95–115). Significant bi-allelic effects were also observed for G396D and Y179C/G396D compound heterozygotes and a marginal mono-allelic effect for variant Y179C (odds ratio (OR)=1.34; 95% CI: 1.00–1.80). A pooled meta-analysis of all published and unpublished datasets submitted showed bi-allelic effects for MUTYH, G396D and Y179C  and marginal mono-allelic effect for variants MUTYH  and Y179C alone .All three models produced very similar results. MUTYH carriers.Overall, this large study refines estimates of disease risk associated with mono-allelic and bi-allelic  MUTYH gene seem to be responsible for a high proportion of the multiple adenoma phenotype families (termed MUTYH-associated polyposis (MAP)) unaccounted for by germline APC mutations  and PUBMED bibliographic databases (http://www.ncbi.nlm.nih.gov/pubmed/), using the search terms ‘MYH or MUTYH and CRC’. In the initial search 55 studies were identified and eight of these were considered for our study  of the selected studies were contacted and were asked to participate by providing a minimum dataset including variables necessary for the analysis , those with one defect as wild type/mutant (WM) and those with no mutation as wild type/wild type (WW). Descriptive statistics were produced on all subject characteristics, risk factors and event data. All populations described in the case–control studies were tested for Hardy–Weinberg equilibrium in controls and the genotype distributions between all groups were compared by χ2-test.Data from all collaborating centres were checked for completeness, coded and merged to form a core database. MUTYH defects (WM vs WW and MM vs WW) as well as of the individual mutations Y179C  and G396D , to identify any variant specific associations. The three logistic regression models were applied after sex and age  stratification as previously described  were estimated and similarly between MUTYH variants and hormone replacement therapy (HRT) among female participants in three studies (the Scottish SOCCS studies and the studies – MUTYH mutations) and the study code or environmental factor  and disease was assessed and interaction was tested by fitting interactive and nested multiplicative models. To assess for any small study effects, we performed Funnel plot analysis and tested for significance using the Harbord test.Three logistic regression models were applied to address confounding co-variates  on the combined datasets investigating the effect of Finally, the relationship between the genotype and CRC was analysed by meta-analysis, combining the effect estimates of all published and unpublished datasets.a in Table 2), which reduces the final OR value, however, by using the META command in the STATA meta-analysis programme, a lower value can be added (0.5 as indicated by model Ib in Table 2) thereby giving a more accurate assessment of risk. However, this is a grouped analysis and therefore cannot be adjusted for confounding co-variates, such as age/sex and study as in models II and III. To account for multiple testing we applied the Bonferroni correction method, and the P-value threshold for significance was estimated to be 0.003.All statistic analyses were conducted using Intercooled STATA version 10.0 . For the logistic regression analyses, it is necessary to add a whole number to any fields containing 0 =28.3, 95% confidence limits (CIs): 6.95–115; 23.1 (95% CI: 3.15–169) and 21.6 (95% CI: 2.94–159), respectively). These risks are conservative, concentrating on the significant logistic regression results – model Ib results presented in P<0.0005, P<0.0005 and P=0.27, respectively – vs 56.7, respectively, P=0.003 based on t-test – All three models of the logistic regression analysis gave consistent results and so the results of the crude analysis (model I) are described below and presented in MUTYH variants  for the MM and a pooled fixed mono-allelic effect of 1.16 (95% CI: 1.00–1.34) for WM genotype  are associated with a 28-fold (95% CI: 6.95–115) increase in CRC risk from the logistic regression analysis. Bi-allelic carriers of the G396D variant and Y179C/G396D compound heterozygotes were also significantly associated with a similar increase in CRC risk (OR=23.1 (95% CI: 3.15–169) and 21.6 (95% CI: 2.94–159), respectively). Although the risk estimate was slightly lower from the overall larger pooled meta-analysis of published and unpublished datasets (OR=10.8 (95% CI: 5.02–23.2)), both G396D and Y179C variants demonstrated bi-allelic effects in this pooled analysis (OR=6.47 (95% CI: 2.33–18.0) and OR=3.35 (95% CI: 1.14–9.89), respectively). A marginal significant mono-allelic effect was demonstrated for the specific variant Y179C (OR=1.34 (95% CI: 1.00–1.80)) and indeed a marginally significant result was also observed in the pooled meta-analysis for MUTYH WM (OR=1.16 (95% CI: 1.00–1.34)) and Y179C variant alone, 1.34 (95% CI: 1.01–1.77). The increased bi-allelic risk of CRC varied when stratified for age and sex but none of the differences were significant, although when stratified by sex, males showed a marginal significant mono-allelic effect for Y179C . The results from this large dataset indicate that the two variants may be acting mechanistically differently; G396D appears to be a true example of recessive Mendelian disease, whereas the results for Y179C are more complex and there is therefore some argument against combining the two variants. However, the results from the Y179C/G396D compound heterozygotes analysis demonstrates an increase in risk similar to G396D bi-allelic carriers, suggesting that the two variants are complementary and analysis of combined MUTYH mutations as historically performed, appears appropriate to assess risk for the whole gene. The rarity of the Y179C allele has made it difficult to truly assess its effect on disease risk, however the large numbers analysed in this report have resulted in the demonstration that both bi-allelic and mono-allelic Y179C variants are associated with disease risk.This large meta-analysis study refines the estimates of CRC risk associated with mutations in the MUTYH wild-type females associated with HRT intake  and is sensitive to variations in population allele frequency because of the rarity of the variant , as well as potential issues of subgroup analysis and multiple testing . Nonetheless, it does appear that this study is the first to demonstrate that the Y179C variant does impart an increased risk of CRC.In conclusion, inactivation of the


The ATP-binding cassette transporter A1 (ABCA1) is essential protein involved in lipid metabolism. The present study was undertaken to detect the possible association of polymorphisms in the ABCA1 gene [rs2230806 (R219K) and rs2230808 (R1587K)] and lipid profile in Greek young nurses.The study population consisted of 308 unrelated nurses who were genotyped and the ABCA1 polymorphisms were detected. Additionally, lipid profile  was evaluated.There was no difference in the genotypic and allelic frequencies of the R219K polymorphism according to lipid profile. The R1587K genotypes differed significantly according to TC, LDL-C and TGs concentration . Particularly, significant difference in TC, LDL-C and TGs concentration was detected between RK and RR genotypes . Women with RK genotype compared to RR genotype had higher concentration of TGs , total cholesterol , and LDL-C .These findings suggest that the R1587K polymorphism of ABCA1 gene was associated with lipid profile of Greek nurses. Women with RK genotype had higher TGs, total and LDL-C concentration compared to RR genotype. These observations may be significant in assessing the risk of CAD since a 1% change in LDL-C is associated with a 1% change of cardiovascular events. Also, TGs concentration were documented to play a significant role in women. However, this needs to be confirmed by larger studies. The ATP-binding cassette transporter A1 (ABCA1) acts as a vehicle for cellular cholesterol which after crossing cell membrane bounds to acceptor molecule such as apolipoprotein (apo) A . Thus, AThis study was undergone to evaluate the influence of these two ABCA1 gene polymorphisms on lipid profile  in young nurses. We also tested if there are any differences in frequency of ABCA1 gene polymorphisms between individuals with low and high HDL-C concentration.The genotyping of 308 Greek female students aged 22.5 (±2.3) years who were attended to the University of Nursing of Technological and Educational Institution was performed. All students had no personal history of CAD and were not taking any drugs. Also, exclusion criteria were diabetes mellitus, thyroid and liver disease, high alcohol consumption, professional athleticism and any chronic disease.All women were attended to the University every day and were staying for 8-10 hours. Women were eating at the school canteen which served typical Mediterranean food. Only one (evening) meal daily was most likely to be different in each student.Additionally, subject were divided to those with high (HDL-C >70 mg/dl) and low (HDL-C <40 mg/dl) HDL-C concentration.The University of Nursing of Technological and Educational Institution ethics committee approved the protocol of this study. All subjects signed an informed consent form.Plasma total cholesterol, TGs, HDL-C and apo A1 were measured using enzymatic colorimetric methods on Roche Integra Biochemical analyzer with commercially available kits (Roche). The serum LDL-C concentration was calculated using the Friedewald formula only in patients with TGs concentration < 400 mg/dl.The ABCA1 gene polymorphisms (R219K and R1587K) were detected using polymerase chain reaction (PCR) and restricted fragment length polymorphism analysis (RFLP's). The PCR was performed using Taq polymerase KAPATaq. For R219K polymorphism the oligonucleotide primers which were used are AAAGACTTCAAGGACCCAGCTT and CCTCACATTCCGAAAGCATTA  presentation and keep the result of the non parametric test that was employed.Differences in lipid levels for the various genotypes were evaluated with one - way analysis of variance (ANOVA) or its non-parametric analogue Kruskal - Wallis H statistic. The Pearson's chi-square test was employed for the categorical variables.All tests were two-tailed and statistical significance was established at 5% (p < 0.05). Data were analyzed using Stata™ .Demographic data, clinical characteristics and lipid profile of the study cohort are shown in Table The distribution of R219K and R1587K polymorphisms was investigated according to Low HDL-C (n = 46) and High HDL-C concentration (n = 104). No statistical difference was observed in both polymorphisms when compared to Low vs High HDL-C concentration . Moreover, no difference in the distribution of the R219K genotypes was detected according to lipid profile   we did not find any association with HDL-C concentration or other lipid parameters. Also, no association between R219K polymorphism and Low or High HDL-C subgroups was found although small number involved in these groups may be a limitation.The frequency of R allele of R1587K polymorphism in our study was 68%. Pasdar et al  reportedAlso, Frikke-Schmidt et al  found thReduced circulating HDL-C can be caused by either genetic and/or environmental factors . The potential mechanisms of interaction between genetic variations and phenotypes contribution are not fully understood. This happens because each study involved different studying population and the environmental interactions could not be ruled out. Thus, in our study the environmental influence was partially diminished. The advantage of our study was that the study cohort was almost homogenous, since the nurses most of the time were following the same day to day program and were eating in the same school canteen. Thus the influence of diet or physical activities were unlikely, which may partially explain the lack of association of R219K or R1587K polymorphisms and HDL-C concentration. However, the influence of smoking cannot be ruled out since 38.5% of students were smokers.It is well known from clinical trials, that 1% change in LDL-C is associated with a 1% change of cardiovascular events, which means that individuals born with favorable genotype (in this case RR genotype of R1587K) have already some advantage compare to less favorable genotypes, since they have lower LDL-C. At that time, this was only a clinical observation. Hopefully in near future we will be able to identify high risk patients according to genetic testing, which the assessment in these days has same cost, time implications and replication problems in independent studies, which are disadvantages in routine clinical practice. Nevertheless, these limitations may become less relevant as technology develops.In summary, the R1587K polymorphism of ABCA1 gene was associated with altered lipid levels in Greek young nurses. Women with RK genotype had higher TGs, total and LDL-C concentration compared to RR genotype. These observations may be significant in assessing the risk of CAD since a 1% change in LDL-C is associated with a 1% change of cardiovascular events and TGs concentration were documented to play a significant role in women.The authors declare that they have no competing interests.VK participated in the development of hypothesis, drafting of the manuscript and carried out the genetic analysis, GK conceived the study and participated in the development of the hypothesis, the study design and drafting of the manuscript, AM participated in the molecular genetic studies, AK performed the statistical analysis and drafting of the manuscript, GV and AK collected the blood samples, DD participated in revising the manuscript critically for important intellectual content, CM and CD participated in the study design and its coordination. All authors read and approved the final manuscript.