Oxidative stress is significant in numerous types of cancer. Tobacco smoke, an important risk factor for oral squamous cell carcinoma (OSCC), is able to generate reactive oxygen species (ROS) and cause oxidative DNA damage. Superoxide dismutase (SOD) is an endogenous antioxidant enzyme that is critical in limiting the oxidative burden effectively. The purpose of this study was to investigate the effects of the mitochondrial SOD2 and Cu/Zn enzyme SOD1 gene polymorphisms on the susceptibility to and clinicopathological characteristics of OSCC, as well as the synergistic effect between these gene polymorphisms and the well-known risk factor of tobacco consumption. Patients with clinically diagnosed OSCC (n=362) and healthy normal individuals (n=358) were investigated for four single nucleotide polymorphisms  by polymerase chain reaction-restriction fragment length polymorphism and DNA sequencing methods. Following adjustment for other confounders, no significant difference was observed in the rs5746136 SOD2 SNPs between the patients and controls. However, the incidence of the CT genotype of SOD2 SNP rs4880 was higher in the patients than in normal subjects in the additive model  and in the dominant model . For those who smoked, the incidence of the CT genotype of rs4880 increased markedly in the patients compared with the controls in the additive model  and in the dominant model . For SOD1, polymorphisms at rs1804450 and rs11556620 were not present in any of the OSCC or control subjects. The results suggest that SOD2 rs4880 may be involved in the tumorigenesis of OSCC and may be useful as a genetic susceptibility marker for OSCC. Oral squamous cell carcinoma (OSCC), the sixth most common type of cancer in the world, is a major cause of morbidity and mortality and >31,000 patients are newly diagnosed with OSCC in the USA annually . Despiteet al reported that cigarette smoking, alcohol consumption and betel quid chewing have all been identified as significant causes of oral carcinogenesis, primarily due to their ability to generate ROS and cause oxidative DNA damage  are enzymes that catalyze the dismutation of superoxide into oxygen and hydrogen peroxide . There aPolymorphic variants of SOD2 have been demonstrated to be factors that may enhance the risk of cancer development . The SODHan Chinese with clinically diagnosed OSCC (n=362) were recruited at the West China Hospital of Stomatology, Sichuan University , from December 2009 to March 2011. Han Chinese healthy individuals (n=358) who visited the general health check-up division of the West China Hospital of Stomatology, Sichuan University were recruited as controls.All of the participants were residents of Sichuan Province, China. All subjects were informed of the detailed study protocol, signed consent forms and were asked to fill out a standardized questionnaire with two trained interviewers. The information required in the questionnaire included: i) Demographic factors, such as age, gender and ethnicity; ii) smoking and alcohol drinking habits ; iii) disease, which consisted of systemic diseases or cancer in other sites; and iv) family history of cancer in parents, brothers and sisters. According to the inclusion criteria, participants with systemic diseases and/or a family history of cancer were filtered out by the standardized questionnaire and their medical records, so none of the participants in the study had a disease (except OSCC in the case group), a family history of cancer or the habit of betel nut chewing (there is no habit of betel nut chewing in Sichuan Province). All subjects in the patient group had their disease histopathologically confirmed and were previously untreated patients in the surgery departments. The OSCC information for all patients was collected from their medical records following their surgeries. Ethical approval was granted by the West China Hospital of Stomatology, Sichuan University ethics committee and all patients gave written consent prior to collection of the samples. Characteristics of the case group and control group are presented in Blood was taken from all participants by peripheral antecubital venous puncture and was stored at −20°C until analysis.2, 2 units Taq polymerase , 10 ng genomic DNA, 0.4 pM each primer and enough ddH2O to make the volume up to 25 μl per reaction.Genomic DNA was extracted using a salting-out method . The DNATaqI, BsaWI, AcuI or BtsI, for 4 h at 60°C or 37°C , dominant (AA vs. Aa/aa) or recessive (AA/Aa vs. aa) inheritance. Genotype frequencies of rs4880 and rs5746136 were compared between the OSCC cases and controls using the unconditional logistic regression. The odds ratios (ORs) with their 95% confidence intervals (CIs) were estimated by unconditional logistic regression. The adjusted P-values (Pas) were estimated by multiple logistic regression. The adjusted ORs (AORs), with their 95% CIs, of the association between the genotype frequencies and OSCC susceptibility were estimated by multiple logistic regression models after controlling for other covariates such as age, gender, smoking and drinking. The Hardy-Weinberg equilibrium was tested with a goodness of fit χ2 test with one degree of freedom to compare the observed genotype frequencies among the subjects with the expected genotype frequencies calculated byPowerStats v1.2 software . Statistical significance was assumed at P<0.05. SPSS Software, version 11.5  was used for all of the statistical analyses. SHEsis software  was applied for analysis of linkage disequilibrium (LD) , but did identify that there were significant differences in smoking  and rs5746136 . For SOD1, polymorphisms at rs1804450 and rs11556620 were not present in any of the OSCC and control subjects, hence these two SNPs were ruled out from subsequent analyses. The AORs and the respective 95% CIs of the genotype distributions of rs4880 and rs5746136 associated with the susceptibility of OSCC between the case group and control group are presented in Furthermore, the Pa, AOR and 95% CI of genotypic frequencies and OSCC were also estimated among individuals with exposure or non-exposure to tobacco consumption. The genotype frequencies of rs4880 were significantly different between the OSCC patients who smoked and the control participants who smoked in the additive model (CT vs. TT) and dominant model  from the Hardy-Weinberg equilibrium for these two loci .The LD values for rs4880 and rs5746136 were evaluated using SHEsis. No significant LD was observed for the two loci; the rThe statistical power in this study was >80%, with an estimated odds ratio of 2.0 .OSCC is the most common type of malignancy of the oral cavity . In the et al suggested that the SOD2 rs4342445 A allele was associated with 30% greater odds for oral cavity tumors in European- and African-American subjects  for evaluation of their association with susceptibility to OSCC in comparison with controls. The selection criteria for these three SNPs were that they are located in the coding region of SOD1, and their single-nucleotide changes would lead to an amino acid substitution. To the best of our knowledge, this is the first study to explore the polymorphisms of rs1804450 Thr/Ile and rs11556620 Asn/Ser that do not have genotype data available from the dbSNP of the NCBI. However, neither of these polymorphisms was identified in the members of the Sichuan Province Han population included in the present study.In this study, no significant difference was observed in the genotype and allele frequencies of rs5746136 SNPs between the patients and controls. However, the C content of rs4880 was significantly higher in OSCC patients, particularly in the OSCC patients who smoked and in male OSCC patients compared with the control group. The C allele frequency of rs4880 was significantly higher in OSCC patients compared with normal subjects . The C allele frequency was also associated with a significantly higher risk of OSCC compared with the TT genotype in smokers . Cigarette smoke is one of the most important free radical-generating carcinogens. It was hypothesized that smoking and more highly active SOD2  may lead to the accumulation of higher levels of hydrogen peroxide and secondary ROS generation, which increases the risk of DNA damage and OSCC. Nevertheless, whether intracellular ROS levels are changed in parallel with the SOD2 rs4880 genotypes in the OSCC microenvironment requires further investigation. The results of the present study corresponded well with other studies on tumors, such as adult brain tumors  , gastricIn conclusion, the present study provides the first evidence that a SOD2 polymorphism  may convey a genetic susceptibility to OSCC in a Han Chinese population, but the rs5746136 polymorphism of SOD2 and the SOD1 polymorphisms did not. These results were consistent with previous studies of other types of cancer. This suggests that rs4880 of SOD2 may be a potential marker for disease diagnosis, further supporting the hypothesis that SOD2 is important in carcinogenesis. Further studies with larger samples in diverse ethnic populations are required to verify these conclusions.


Primary open-angle glaucoma (POAG) is one of the leading causes of blindness worldwide. The association between the APOE ε2/ε3/ε4 polymorphism and the risk of POAG has been widely reported, but the results of previous studies remain controversial. To comprehensively evaluate the APOE ɛ2/ɛ3/ε4 polymorphism on the genetic risk for POAG, we performed a systematic review and meta-analysis of previously published studies. The PubMed and Web of Science databases were systematically searched to identify relevant studies. Data were extracted from these studies and odds ratios with corresponding 95% confidence intervals were computed to estimate the strength of the association. Stratified analyses according to ethnicity and sensitivity analyses were also conducted for further confirmation. A total of nine studies were eligible for the meta-analysis, and these studies included data on 1928 POAG cases and 1793 unrelated match controls. The combined results showed that there were no associations between the APOE ε2/ε3/ε4 polymorphism and POAG risk in any of the 10 comparison models. The analysis that was stratified by ethnicity subgroups also failed to reveal a significant association. The sensitivity analysis confirmed the stability and reliability of the findings. There was no risk of publication bias. Our meta-analysis provides strong evidence that the APOE ε2/ε3/ε4 polymorphism is not associated with POAG susceptibility in any populations. Glaucoma is defined as a multifactorial optic neuropathy that is characterized by a progressive loss of retinal ganglion cells in the optic disc or retinal nerve fiber . GlaucomAPOE is the major apolipoprotein of the central nervous system and plays important roles in several biological processes and in neural function . APOE isThe APOE gene has been mapped to the 19q13 region, and its common polymorphism has three alleles in exon 4, namely, ε2, ε3, and ε4. These three alleles define the following six APOE phenotypes:ε2/ε2, ε3/ε3, ε4/ε4, ε2/ε3, ε2/ε4, and ε3/ε4 . The APOIn the past decade, a great number of molecular epidemiological studies have been performed to evaluate the association between APOE gene polymorphisms and POAG susceptibility in diverse populations, but results are somewhat controversial and underpowered likely because of the limitations of limitation of individual studies. Therefore, we carried out this meta-analysis to determine whether this polymorphism is associated with the risk of APOE by collecting and sorting previously published studies.Systematic literature searched of the Pubmed and Web of Science databases were performed to identify relevant studies that have investigated the association between POAG risk and the APOE ε2/ε3/ε4 polymorphism using the following search terms: “apolipoprotein E or APOE” and “glaucoma or POAG” . Only those published in the English language with available full text articles were included. All studies return by these searches were retrieved, and the references in these articles were also checked for additional relevant published articles. For studies with overlapping data that were published by same investigators, only the most recent or complete study was included. Meeting abstracts, case reports, editorials, review articles, and letters were excluded. Studies included in the current meta-analysis had to meet the following criteria: (1) contain evaluations of the APOE ε2/ε3/ε4 polymorphism and POAG risk, (2) have an unrelated case-control design, and (3) have sufficient data  to estimate an odds ratio (OR) and its 95%CI. Major reasons for the exclusion of studies included a lack of POAG research, a lack of a control population, duplication of previous publications and unavailable genotype frequencies. Two separate investigators reviewed and extracted data from all eligible publications independently based on the inclusion and exclusion criteria listed above. Discrepancies were adjudicated by a third reviewer until consensus was reached on all items. The following variables were extracted from each study if available: the first author’s surname, the year of publication, the country of origin, the ethnicity of the study samples, the numbers of cases and controls, and the numbers of cases and controls with different genotypes. Ethnic backgrounds were categorized as Caucasian, Asian or Other . All statistical tests in the current meta-analysis were conducted using Stata . All P-values were two-sided, and p<0.05 was considered statistically significant. The strength of the association between the APOE ε2/ε3/ε4 polymorphism and the risk of APOE was measured using odds ratios (ORs) with 95% confidence intervals (CIs). In our meta-analysis the ε3/ε3 genotype and ε3 allele variant were used as the reference group. We examined the association between genetic variants (both ε2 and ε4 variation) and POAG risk with an allelic comparison model (ε2 vs ε3 or ε4 vs ε3), and made comparisons with homozygotes (ε2/2 vs ε3/3 or ε4/4 vs ε3/3), heterozygotes (ε2/3 vs ε3/3 or ε3/4 vs ε3/3), the dominant genetic model (ε2/2 + ε2/3 vs ε3/3 or ε3/4 + ε4/4 vs ε3/3), and the recessive genetic model (ε2/2 vs ε3/3+ ε2/3 or ε4/4 vs ε3/3 + ɛ3/4). Subgroup analyses were also performed by ethnicity.2 statistic was then used to quantify the proportion of the total variation that was due to heterogeneity; I2<25%, 25–75% and >75% represented low, moderate or high degrees of inconsistency, respectively [The existence of heterogeneity between studies was ascertained with the Chi-square-based Q statistic. The Q-test yielding P values greater than 0.05 indicated a lack of heterogeneity between studies and resulted in the pooled OR estimate of each study being calculated using a fixed-effects model (the Mantel–Haenszel method) ; otherwiectively .Hardy-Weinberg equilibriums (HWEs) were calculated with goodness-of-fit tests . One-way sensitivity analyses were carried out by consecutively omitting one study at a time to assess the stability of the meta-analysis results. Visual inspection of the asymmetry of funnel plots was carried out to assess potential publication bias. Begg’s funnel plots and test were used to statistically estimate publication bias (P<0.05 was taken to indicate significant publication bias) . Our initial search generated 62 potentially relevant articles in the PubMed and Web of Science databases. Based on titles and the contents of the abstracts, 43 articles were excluded. Of the remaining 19 articles, two were not case-control studies, three did not report usable reported data, two were meeting abstracts, one was not published in English, and two studies were not in HWE; these studies were also excluded. In total, nine studies of the APOE ε2/ε3/ε4 polymorphism and its influence on POAG risk were included in the current meta-analysis based on our inclusion/exclusion criteria -36. The We also performed subgroup analyses that were stratified by ethnicity. Overall, no obvious evidence of associations between the APOE ε2/ε3/ε4 variants and the risk of POAG were found in any Asian or Caucasian genetic model. The results of these analyses are shown in heterogeneity < 0.001; ε2/3 vs ε3/3: Pheterogeneity =0.037; ε3/4 vs ε3/3: Pheterogeneity = 0.001; and ε3/4 + ε4/4 vs ε3/3: Pheterogeneity =0.001. When patients were stratified based on ethnicity, the heterogeneity of the Caucasian samples disappeared in the following four genetic models: ε4 vs ε3: Pheterogeneity = 0.592; ε2/3 vs ε3/3: Pheterogeneity = 0.265; ε3/4 vs ε3/3: Pheterogeneity = 0.839; and ε3/4 + ε4/4 vsε3/3: Pheterogeneity = 0.799. Data of heterogeneity test are listed in There was significant heterogeneity in the following four genetic models: ε4 vs ε3: PSensitivity analyses were performed after sequential removal of each of the included studies to examine the influence of each individual data-set on the pooled ORs. No single study qualitatively changed the pooled ORs, which indicates that the results of this meta-analysis were basically stable and robust .Funnel plots and Egger’s tests were used to assess potential publication biases of the literatures. The shapes of the funnel plots did not reveal any evidence of obvious asymmetries . SimilarPrimary open-angle glaucoma (POAG) is the most frequent type of glaucoma and one of main causes of irreversible blindness worldwide . POAG isAPOE is a 36-kDa glycoprotein that plays an essential role in lipid and cholesterol transport ,14. The To our knowledge, this is the first meta-analysis of published studies that has investigated whether the APOE ε2/ε3/ε4 polymorphism is associated with the risk for POAG. In this study, nine eligible studies comprising 1928 patients with POAG and 1793 unrelated matched controls were included. Overall, we found no obvious evidence for an association between the APOE ε2/ε3/ε4 polymorphism and the risk for POAG in any allelic or genotypic model. Furthermore, analyses of subgroups created based on ethnicity also failed to reveal any significant association of this polymorphism and POAG susceptibility.Heterogeneity is a potential problem that might affect the interpretation of our results. In our meta-analysis, significant heterogeneity was found for the following genetic models:ε4 vs ε3, ε2/3 vs ε3/3, ε3/4 vs ε3/3 and ε3/4 + ε4/4 vs ε3/3. However, in the subgroup analyses stratified by ethnicity, the heterogeneity disappeared among Caucasians in these four genetic models. This heterogeneity may have resulted from differences in the patients’ genetic backgrounds, living environments or genotyping methods. Moreover, the leave-one-out sensitivity analyses revealed that no single study influenced the overall results qualitatively, which indicates that our results are reliable. Additionally, neither the shapes of the funnel plots nor the statistical results revealed publication biases in our meta-analysis.To some extent, some limitations of the current meta-analysis should be acknowledged when interpreting the results. First, we only included published data from the selected databases; it is possible that some relevant published studies or unpublished studies were missed, and this may have biased the results. Second, due to the lack of POAG subtype information from the eligible studies, we were unable to perform sub-group analyses based on POAG types, , which play a crucial roles in genetic analyses. Third, due to the limited availability of published results, the number of publications included in our meta-analysis was only seven; this low number is bound to bias the analyses results. We expect that more studies with larger samples and randomized -controlled trials will become available. Finally, only papers that were published in English and studies with available full-text articles were included in the current meta-analysis; therefor, some eligible studies that have not been unpublished or were reported in other languages were missed, which may influence the pooled results. Despite these limitations, our meta-analysis also has some advantages. First, we significantly increased the statistical power of our meta-analysis by including a substantial number of cases and controls from different studies. Second, the methodological issues of meta-analysis, such as heterogeneity, publication bias, and the stability of results were all carefully investigated. Third, the qualities of the case-control studies identified in our meta-analysis were satisfactory and met our inclusion criteria.In summary, this meta-analysis provided evidence that the APOE ε2/ε3/ε4 polymorphism is not associated with POAG susceptibility. Well-designed case-control studies with adequate numbers of cases are warranted to confirm our findings.Checklist S1(DOC)Click here for additional data file.


LHCGR) high function polymorphism (rs4539842/insLQ) and outcome to controlled ovarian hyperstimulation (COH).The aim of this study was to determine the relationship between a purported luteinizing hormone/chorionic gonadotropin  that was 142 bp from insLQ. The association of the insLQ and rs4073366 alleles and outcome to COH  administration, the number of eggs retrieved and ovarian hyperstimulation syndrome (OHSS)) was determined.This was a prospective study of 172 patients undergoing COH at the Fertility and IVF Center at GWU. DNA was isolated from blood samples and a region encompassing the insLQ and rs4073366 were in linkage disequilibrium (LD) and no patients were homozygous for both recessive alleles . The insLQ variant was not significantly associated with any of the main outcomes to COH. Carrier status for the rs4073366 C variant was associated (P = 0.033) with an increased risk  of developing OHSS.Increasing age and higher day 3  FSH levels were significantly associated with poorer response to COH. We found that both insLQ and patient response to COH. Interestingly, rs4073366 C variant carrier status was associated with OHSS risk. To the best of our knowledge, this is the first report suggesting that LHCGR genetic variation might function in patient risk for OHSS.While age and day 3 FSH levels were predictive of outcome, we found no association between  Various phenotypic predictors of ovarian responsiveness (i.e. ovarian reserve testing (ORT)) [a priori determination of patient response to COH [FSHR) [ESR) [CYP19A1) [Controlled ovulation hyperstimulation (COH) is the cornerstone of assisted reproduction. The use of exogenous gonadotropins subverts the natural process of single follicular dominance and allows for the recruitment and maturation of multiple ova during the ovarian cycle. Although this technique has vastly enhanced the potential for g (ORT)) -4 have be to COH  and miniH [FSHR) -17, estrR) [ESR) -8,18-20 CYP19A1) ,21 genesCYP19A1) ,22,23 whThe luteinizing hormone receptor (LHR) protein is a G protein-coupled hormone receptor (GPCR)  and is eLHCGR) gene (~69 kb) located on chromosome 2p21 [LHCGR harbors at least 300 known polymorphisms [insLQ) has been reported that results in the addition of two amino acids (Leu-Gln) in the signal peptide region of the receptor [insLQ polymorphism is approximately 0.3 in individuals of Caucasian and African descent [insLQ impacts LHR by potentially altering protein folding, trafficking and membrane insertion. Functionally, the insLQ variant LHR protein displays higher activity in cell culture potentially due to improved trafficking and increased cell surface expression, but unrelated to alterations in hCG binding [insLQ allele exhibit shorter disease-free survival than non-carriers [LHCGR resides near a potential susceptibility locus for polycystic ovary syndrome (PCOS), which is characterized by anovulation/oligo-ovulation and elevated androgen levels [insLQ was detected at a higher level (40.5%) in patients who experienced ovarian hyperstimulation syndrome (OHSS) compared to controls (27.5%), but this did not achieve statistical significance potentially due to a small sample size [LHR is encoded by the luteinizing hormone/chorionic gonadotropin receptor  nearby insLQ exhibited an increased risk of developing OHSS.Patient response to COH is multi-factorial in nature. To date, there is no reliable test or algorithm that combines both genetic and clinical factors for predicting patient response to fertility therapy. As a result, the focus of this ongoing work is to identify genetic factors that are predictive of clinical response to COH. The This study was approved by George Washington University Institutional Review Board. Written informed consent was obtained from the participants of this study. The study was open to all adult (>18 years of age), female patients seeking treatment at the GW Fertility and IVF Center at GWU Medical Center. One hundred seventy-two patients were recruited into the study from 2010–2011. All IVF patients being monitored while taking injectable gonadotropins were invited to participate. Prior to beginning treatment, all patients had undergone an evaluation that included ovarian reserve testing, semen analysis , uterine cavity study and thyroid screening. Controlled ovarian stimulation was accomplished with either luteal down regulation using a GnRH agonist  followed by recombinant FSH  administration or with recombinant FSH  administration in combination with a GnRH antagonist . The initial FSH dose was dependent upon patient age and basal ovarian reserve testing. After initial follicular monitoring , FSH dosing was titrated based upon the ovarian response. hCG trigger was withheld for levels E2 over 4000 pg/ml thus minimizing risk for OHSS. Both control and OHSS groups had similar risk factors including those identified at time of hCG trigger. Ovarian response to gonadotropin was observed. The primary endpoint of the study was the estradiol level on day of hCG injection. Secondary clinical endpoints included number of ovarian follicles counted on day of hCG number of eggs retrieved and the incidence of OHSS. Ovarian hyperstimulation syndrome was defined clinically based on the criteria established by Navot ,59.insLQ and rs4073366 was amplified using 10 pmol/μl forward (5’-CACTCAGAGGCCGTCCAAG-3’) and reverse (5’-GGAGGGAAGGTGGCATAGAG-3’) primers [Taq L nucleotide mix, 6 μl MgCl2 DNA Polymerase , 3.75 μl of H2O, and 10.0 μl of genomic DNA. The PCR cycling conditions were as follows: 1 cycle of 95°C for 2 minutes, followed by 32 cycles of 95°C for 30 seconds, 56°C for 30 seconds and 72°C for 30 seconds and a 7 min final extension at 72°C. PCR products were purified  and 20–40 ng/μl of samples were sequenced using BigDye Terminator technology  by Eurofins MWG Operon . Multiple sequence alignments were carried out using ChromasPro software (Technelysium Pty Ltd).Approximately 5 mL of blood was collected for genetic analysis at the GW IVF Center. Total genomic DNA was extracted from 200 μl EDTA anti-coagulated venous blood using a QiaCube automated instrument with the QIAamp DNA Blood Mini Kit . The samples were frozen at −80°C until the time of genotyping. A 291 base-pair target region encompassing  related to genotype were tested using a step-down bootstrap resampling method (the STEPBOOT option in PROC MULTTEST in SAS) . This me2) levels, were 1.8 IU/ml, 7.0 IU/L, and 40.8 pg/ml, respectively. On average, patient gonadotropin stimulation lasted 12 days. Mean E2 levels on the day of hCG administration was 1780 pg/ml and the median number of follicles and eggs retrieved was 10 and 9, respectively. Eighteen patients (10.5%) experienced moderate to severe OHSS  in a patient with poor oocyte recovery following IVF [insLQ). As a result, we analyzed insLQ through direct sequencing of a 291 base-pair region of exon/intron 1. As shown in Table insLQ/no-insLQ, no-insLQ/insLQ and insLQ/insLQ were ~0.62, 0.34 and 0.035, respectively (n = 172). Another polymorphism, rs4073366 G > C, occurs ~142 bp downstream of insLQ and was detected during sequencing. We attempted alternative methods  to omit rs4073366 from our study of insLQ, but these yielded unreliable results. Consequently, we included this single nucleotide polymorphism (SNP) in our analysis because of its potential impact on any apparent associations between insLQ and COH outcome. For rs4073366, G/G, G/C and C/C variants occurred at relative proportions of ~0.72, 0.25 and 0.03, respectively in our patient population. Both variants were in Hardy-Weinberg equilibrium (HWE) and insLQ and rs4073366 were in significant LD  as determined by pair-wise LD estimation (Table insLQ was associated with not being CG or CC for rs4073366 (Table P = 0.012). In addition, we did not find any individuals who were homozygous for both insLQ and rs4073366, nor did we identify any patients who had the insLQ, rs4073366 “C” haplotype (data not shown).Recently, a novel, potentially inactivating, mutation was detected that resided within the wing IVF . This muinsLQ and rs4073366 polymorphisms as covariates. In the multivariable models (Table P = 0.03), fewer number of follicles (P < 0.0001) and a lower number of eggs retrieved (P = 0.0002). Increasing basal FSH level was associated with fewer follicles (P = 0.009) and eggs retrieved (P = 0.0002), but not E2 levels (P = 0.46) on day of hCG. All three main outcomes were positively correlated with each other  (data not shown). Finally, self-identified race/ethnicity was not significantly associated with any of the three main patient outcome measures (data not shown).Of the 172 patients, up to 17 patients were excluded  from multivariable analysis because of missing data values related to being screened at outside centers that did not have complete ovarian reserve testing or they did not undergo follicular monitoring on day of hCG administration. Both age and ORT  have been prognostic clinical indicators of outcome to COH (52). As a result, regression models predicting estradiol level on day of HCG, number of follicles, and number of eggs retrieved included age, day 3 FSH level, day 3 estradiol levels, and the insLQ genotypes reached statistical significance (not shown). Similarly, results for rs4073366 genotype were also not significant for these three outcomes (not shown). We next examined the 6 non-zero combination genotypic groups and, again, found no significant differences for any of the outcomes when each mean was compared to the overall mean (Table insLQ and were heterozygous (GC) for rs4073366 (i.e. no-insLQ/no-insLQ + CG) to have increased mean estradiol level on day of hCG compared to the mean across all other groups (P = 0.10). The insLQ polymorphism (and rs4073366) was not associated with IVF protocol type, age, or basal FSH or E2 levels (data not shown).None of the pairwise differences comparing estradiol levels, number of follicles, and number of eggs retrieved among the 3 an Table . HoweverinsLQ variant is purportedly a high-function allele and, accordingly, might place patients at a higher risk of OHSS. As a result, we tested whether either insLQ or rs4073366 were associated with an increased risk of OHSS. Because of the small number of OHSS patients, logistic regression analyses were performed without adjustment for covariates. Intriguingly, the insLQ variant was not associated with OHSS by either genotype (P = 0.788) (data not shown) or insLQ carrier status (Table insLQ/C haplotype was significant (P = 0.023) for OHSS risk  (data not shown).The LHCGR genetic variation influences response to COH. We focused our analysis on the insLQ polymorphism (rs4539842) and the rs4073366 G > C SNP located downstream of insLQ in intron 1. We found that insLQ was not associated with patient response to COH, nor was it a predictor for OHSS. Therefore, it is possible that the improved function conferred to LHR by this polymorphism in vitro[insLQ activity was previously investigated in HEK-293 cells which may not accurately replicate the behavior of the insLQ receptor variant ovarian granulosa cells [LHR-mediated signaling plays an important role in patient response to exogenous gonadotropins (i.e. hCG) administered during COH and inter-individual variability in LHR activity could significantly impact outcome. As a result, we investigated whether  in vitro is not rsa cells . In contFSHR Thr307Ala polymorphism has been linked with iatrogenic OHSS in an Indian population [FSHR polymorphism has not been associated with OHSS, but it is potentially predictive of the severity of symptoms [BMP15 variation, such as the rs3810682 SNP , has also been implicated in OHSS [VEGFA gene variation was recently identified as a risk allele  for OHSS [LHCGR was associated with serum steroid hormone binding globulin (SHBGs) levels (62), which could result in elevated serum concentrations of androgens and estrogen. However, the impact of LHCGR polymorphisms  on SHBG levels in not currently known.Very little information exists regarding polymorphisms that are predictive of patients developing OHSS. For example, the pulation , but notpulation  or Brazipulation . The welsymptoms . In addi in OHSS ,65. Finafor OHSS . Given tLHCGR mRNA processing yielding a splice variant with altered activity [APOE mRNA and has been associated with decreased risk of Alzheimer’s disease (AD) in males carrying the APOE ϵ4 allele [APOE has been linked to reproductive efficiency [APOE mRNA stability. Although beyond the scope of this investigation; future work is focused on investigating the molecular consequences of rs4073366 on LHCGR function.While rs4073366 is a potential predictor of OHSS risk, the functional consequences of this polymorphism on LHR function are yet to be elucidated. rs4073366 has a major allele of “C” on the “+” strand (“G” on the “-“strand in this study) and resides in a cryptic 3’ splice acceptor site (data not shown) which could potentially impact activity . In addi4 allele . Given tficiency -70, it iLHCGR variability and its influence on COH. Here, we provide the first report of an association between LHCGR genetic variability and OHSS risk. The relevance of the rs4073366 polymorphism OHSS should be evaluated in additional patient populations. In addition, because OHSS is multigenic in nature, future work is warranted to investigate whether rs4073366, and other LHCGR variants, genetically interact with other loci to predict patient response to COH.Outcome to COH is multi-factorial, variable and unpredictable. There have been few studies that have investigated COH: Controlled ovarian hyperstimulation; OHSS: Ovarian hyperstimulation syndrome; SNP: Single nucleotide polymorphism.The authors declare that they have no competing interests associated with this work.TO: Conceived of the study, participated in its design, carried out molecular analyses, assisted in data analysis and drafted the manuscript. MK: Conducted statistical analyses, assisted with drafting the manuscript. AH: Participated in study design, assisted in data analysis and drafted the manuscript. AC: Carried out molecular analysis with TO. IG: Processed samples, carried out molecular analysis with TO. SS: Worked with MK on all statistical analyses. DF: Conceived of the study, participated in its design, recruited participants, assisted with drafting the manuscript. PG: Conceived of the study, participated in its design, recruited participants, assisted with drafting the manuscript. All authors read and approved the final manuscript.


Strokes, typically involving vertebral artery dissection, can follow cervical spinal manipulative therapy, and these types of stroke occur rarely. There is disagreement about whether a strong association between neck manipulation and stroke exists. An earlier systematic review found two relevant studies of association that used controls, which also discussed the limitations of the two papers. Our systematic review updates the earlier review, and aims to determine whether conclusive evidence of a strong association exists.PRISMA guidelines for systematic reviews were followed, and the literature was searched using a strategy that included the terms ‘neck manipulation’ and ‘stroke’ from the PubMed, Embase, CINAHL Plus and AMED databases. Citations were included if they met criteria such as being case–control studies, and dealt with neck manipulation and/or neck movement/positioning. Papers were scored for their quality, using similar criteria to the earlier review. For individual criteria, each study was assigned a full positive score if the criterion was satisfied completely.Four case–control studies and one case–control study, which included a case- crossover design, met the selection criteria, but all of them had at least three items in the quality assessment that failed to be completely positive. Two studies were assessed to be the most robustly designed, one indicating a strong association between stroke and various intensities of neck movement, including manipulation, and the other suggesting a much reduced relative association when using primary care practitioners’ visits as controls. However, potential biases and confounders render the results inconclusive.Conclusive evidence is lacking for a strong association between neck manipulation and stroke, but is also absent for no association. Future studies of association will need to minimise potential biases and confounders, and ideally have sufficient numbers of cases to allow subgroup analysis for different types of neck manipulation and neck movement. A predefined search strategy, using the PUBMED, EMBASE, CINAHL PLUS and AMED medical databases, was employed to find studies that measured the association between neck manipulation and stroke. The study followed the PRISMA guidelines for systematic reviews, and the quality of each of the extracted studies was assessed using similar criteria that had been developed for a previous systematic review.Conclusive evidence seems to be lacking for a strong association between neck manipulation and stroke, and also appears to be absent for no association.Informed consent should be obtained from patients before neck manipulation is administered, advising them that neck movements, including manipulation, may increase the risk of a rare form of stroke.Premanipulative screening of vertebral arteries is still warranted, and Doppler ultrasound velocimetry shows potential for this.Neck manipulation, often referred to as cervical spinal manipulative therapy (cSMT), is a popular form of patient care. It is provided for the relief of cervical spine related conditions to approximately 80% of Australian chiropractic patients , and theIt is recognised that cases of stroke, typically involving vertebral artery dissection (VAD) and to a lesser extent internal carotid artery dissection (ICAD), can occur soon after cSMT –10. TherDissection of the vertebral artery (VA) and internal carotid artery (ICA) involves severe headache and neck pain before the presentation of stroke in approximately 80% of cases ,13, and The fact that strokes can be triggered by ordinary daily activities involving movements or sustained positioning, especially cervical rotation and/or extension , suggestThere is controversy about the level of risk of stroke from cSMT, with one view claiming that there is a strong association between the two , and anoThe design of this systematic review of the literature follows the Preferred Reporting Items for Systematic Reviews & Meta-Analysis (PRISMA) guidelines , as descA specific registered protocol for systematic reviews of studies dealing with risk assessment seems to be lacking. We used a similar protocol to that employed by Rubinstein et al.  in theirStudies with designs, such as randomised control trial, cohort, case–control and case-crossover, were eligible for inclusion, whereas case reports, case series, abstracts and letters to the editor were excluded to ensure examination of the highest standard of research. Other criteria for inclusion were that studies: (i) had a population with a confirmed or assumed diagnosis of CAD, and also a control group, (ii) had individuals exposed to specific incidences of cSMT or mild neck trauma, noteworthy neck movements or positioning and (iii) were full reports. Studies were excluded if the dissections were because of surgery, arteriography or major trauma.Databases were accessed from 1966 to 2012, and included PubMed and Embase, which were last searched in 2005 by Rubinstein et al. (The search strategy used MESH headings that included: ‘neck manipulation’ combined (Boolean AND) ‘stroke’ with (NOT) ‘surgery’, with (NOT) ‘animal’. Relevant combinations of free text terms, such as ‘cervical manipulation’ (AND) ‘vertebral artery dissection’ (OR) ‘internal carotid artery dissection’, were used for all databases. No restrictions were placed on the year of the study, gender or age of patients, or language. Papers were limited to those that deal with cSMT, or neck movement/positioning. All abstracts that met this search strategy were examined, as were the associated bibliographies. To test the reliability of the search strategy, both MJH and KV made searches, blinded from each other, using PubMed and the following string: ‘neck manipulation’ AND ‘stroke’, and these searches were compared.MJH collected only the eligible papers and scored their quality using the criteria set out in Extracted data included characteristics of the study population, the risk factor, i.e. cSMT or neck movement/positioning, potential confounders and the strength of association.The scorers addressed the types of potential bias that may occur in the selected papers, such as selection and recall bias. This was mainly done from the study level rather than the outcome level, and is discussed qualitatively rather than making any attempt to quantify the bias.crude) and/or adjusted odds ratios (OR adj), if available and 95% CIs.Results were expressed as crude odds ratios , (non-parametric bootstrap 95% CI = 0.64–46.28)];Rothwell et al. , in a readj = 6.62 (95% CI = 1.4–30)] ] ;crude = 2.1 (95% CI = 0.5–9.1); OR adj = 1.5 (95% CI = 0.3–6.9), p = 0.3]. In a cumulative analysis of all the mechanical trigger factors, including cSMT, a significant difference was found between the two groups (p = 0.01);Dittrich et al. , conductCassidy et al.  is an excrude = 3.11 (95% CI = 1.16–8.35) and accelerated bias corrected bootstrap 95% CI = 1.07–9.60, and for visits within 3 days the case-crossover study gave OR crude = 17.7 (95% CI = 2.04–153.3), bootstrap unavailable. However, for the PCP visits similar associations were observed for patients aged < 45 years and ≥ 45 years. For headache or cervical visits within 7 days for patients aged < 45 years, the case–control study resulted in OR crude = 37.60 (95% CI = 4.80–294), and for within 3 days the case-crossover study yielded OR crude = 28.00 (95% CI = 3.44–227.58), and in both cases the bootstrap was unavailable. Sensitivity analysis resulted in attenuation of the estimates towards the null with lower positive predictive values, but the associations remained positive and significant (data not presented);Positive associations, especially with cervical and headache related visits, were only observed for chiropractic patients aged < 45 years, with 25 cases (24.5%) and 27 controls (6.6%) within 7 days for general visits. For headache or cervical visits within 7 days, results in the case–control study were OR crude = 12.80 (95% CI = 1.58–104.3), OR adj = 12.7 (95% CI = 1.43–112.0)]. There was a strong observed association with recent head or neck trauma, with 30 cases  (64%) compared with three controls (7%) [OR crude = 25.5 (95% CI = 5.71–96.9) and OR adj = 23.5 (95% CI = 5.71–96.9)].Thomas et al. , in a reAs per Information bias for identifying exposures for the two population-based studies is possible because of inaccuracy of the public health insurance billing codes for chiropractic and PCP visits. Some chiropractic visits may not have involved cSMT, thereby inflating the observed association, and some PCPs may have administered cSMT, which would have decreased the measured relative association for chiropractic visits. To obtain exposures retrospectively, Thomas et al.  relied oThe use of stroke patients for controls might artificially inflate the association for cSMT because less healthy and stroke-prone individuals, often with a lower socio-economic background, are less likely to attend a chiropractor ,4. SelecPatients with headache and neck pain from CAD may seek cSMT for relief, thereby causing an over-estimation of association ,25. CassCassidy et al.  used a cAlthough Dittrich et al.  and CassAn accurate risk-benefit analysis for cSMT remains unavailable and additional research in this field is needed. However, the same need for research seems to apply to other therapies for neck related conditions, such as cervical mobilisation and electro-physical modalities, which also require informed consent. The potential risks of cSMT need to be placed in context with the high gastrointestinal complication rate of many NSAIDs used for arthritic conditions including neck pain that have caused many fatalities  includinAccording to Gordis: “If the absolute risk is low, even if the relative risk is significantly increased to exposed individuals, the actual risk to exposed individuals will still be very low” . Stroke As the possibility of an association between cSMT and VAD is unable to be ruled out, practitioners of cSMT are obliged to take all reasonable steps that aim to minimise the potential risk of stroke. There is evidence that cervical rotation places greater stresses on vertebral arteries than other movements such as lateral flexion , and so All of the extracted studies yielded inconclusive evidence regarding a strong association or no association between cSMT with CAD related stroke. Future studies regarding CAD risk need to aim to eliminate or at least minimise bias and confounding. Ideally, studies should have sufficient numbers of patients to enable subgroup analyses regarding different types of cSMT and neck movements/positioning. However, the rarity of these strokes will make accurate measurements of association very difficult, and it may not be achievable in the foreseeable future.MJH was responsible for the study design, extracted the relevant citations, scored studies for their quality, determined the presence of biases and confounders, and was responsible for referencing, and writing the manuscript. KV, CF, OL and GKH scored the relevant studies in a blinded fashion, checked for biases and confounders, and provided input regarding the manuscript. APB made the final decision in cases where consensus was unable to be reached, provided statistical advice regarding the studies and assisted in drafting the manuscript.


Genome-wide association studies have reported that a polymorphism near the estrogen receptor gene (ESR1) (rs2046210) is associated with a risk of breast cancer, with the A allele conferring an increased risk. However, considering the controversial results from more recent replicated studies, we conducted a case-control study in an independent Chinese Han population and a meta-analysis to clarify the association of this polymorphism with breast cancer risk.A hospital-based case-control study including 461 cases and 537 controls from a Chinese Han population was conducted initially, and this study showed that the rs2046210 A allele was significantly associated with breast cancer risk, with an OR of 1.32 (95% CI  = 1.10–1.59). Subsequently, a meta-analysis integrating the current study and previous publications with a total of 53,379 cases and 55,493 controls was performed to further confirm our findings. Similarly, a significant association between this polymorphism and breast cancer risk was also observed in the overall population especially among Asians, with ORs for per A allele of 1.14 (95% CI  = 1.10–1.18) in the overall population and 1.27 (95% CI  = 1.23–1.31) in the Asian population.Our results provide strong evidence to support that the common polymorphism near the ESR1 gene, rs2046210, is associated with an increased risk of breast cancer in Asian and European populations but not in Africans, although the biological mechanisms need to be further investigated. According to global cancer statistics in 2008, breast cancer (BC) is the most common malignant tumor among women worldwide, accounting for 23% of new cancer cases and 14% of cancer deaths. In several developing countries, such as China, BC has surpassed cervical cancer and become the leading cause of cancer death among females Recent genome-wide association studies (GWAS) have demonstrated numerous low-penetrance susceptibility loci were significantly associated with BC A total of 461 incident cases and 537 controls were enrolled between June 2009 and December 2011 from Union Hospital of Huazhong University of Science and Technology, Wuhan, China. All the cases were histopathologically confirmed with primary BC and none of them had received neo-adjuvant treatment. The controls were randomly selected from a health check-up program at the same hospital during the same period. The inclusion criteria for controls were that they had to be cancer-free individuals who were frequently age-matched (±5 years) to the BC cases. All subjects were unrelated ethnic Han Chinese from Wuhan and its surrounding region in the central region of China. Written informed consent was signed by each participant, and 2-ml peripheral blood samples were collected on recruitment. According to the NCCN  guidelines for BC For each subject, genomic DNA was extracted from a 2-ml peripheral blood sample using the RelaxGene Blood System DP319-02  according to the manufacturer's instructions. The genotype of rs2046210 was carried out using the Taqman SNP Genotyping Assay  on a 7900HT Fast Real-Time PCR System . To assess the quality of genotyping, we conducted re-genotyping of a randomly selected 5% of the samples and obtained 100% concordance rate.2χ test and t-test. The Hardy-Weinberg equilibrium (HWE) for genotypes in the controls was assessed by the goodness-of-fit 2χ test. An unconditional multivariate logistic regression model was used to estimate the associations between genotypes and BC risk by calculating the odds ratios (ORs) and 95% confidence intervals (CIs) after adjusting for age and menopausal status. To avoid the assumptions of genetic models, dominant, recessive and additive models for rs2046210 were also assessed. In addition, stratified analyses by menopausal status, estrogen receptor (ER) and progesterone receptor (PR) status were further carried out to evaluate the role of rs2046210 in BC risk. All statistical tests were two-sided and performed using the SPSS 12.0 computer program.Differences in the distribution of demographic characteristics between the cases and controls were evaluated by using the P>0. 05). Reviews, simple commentaries and case reports were excluded. If the studies had overlapping subjects, the one with the largest samples was finally included.To further investigate the association between rs2046210 and BC risk, we carried out a meta-analysis combining previous publications and the current study. We searched PubMed, EMBASE, ISI Web of Science databases and CNKI  for literature published in any language up to June 2012 using the keywords combinations of “rs2046210 or 6q25.1” and “breast cancer, breast carcinoma or breast neoplasm”. The references of retrieved articles and reviews were also checked for missing information. The literature that was included needed to meet the following criteria: (1) the study evaluating the association between rs2046210 and BC risk; (2) providing data for calculating genotypic ORs with corresponding 95% CI; (3) the genotypes in control conforming to Hardy-Weinberg equilibrium  P value greater than 0.1 for Q statistics; otherwise, a random-effects model of the DerSimonian and Laird method was used P values were two-sided with a significance level at 0.05.For each study, the following data were extracted: first author, year of publication, geographic location, ethnicity of the study population, study design, study method, control source, sample size, and frequencies of genotypes in cases and controls. The ORs were calculated for the risk allele A versus the wild allele G. Genotype AG versus GG, AA versus GG, dominant, recessive and additive models were recalculated from parts of the included studies because some research did not provide sufficient data. The between-study heterogeneity was assessed by Cochran's http://www.prisma-statement.org).In order to ensure the rigor of this current meta-analysis, we designed and reported it according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement and the checklist is shown in P = 0.369). The percentage of premenopausal women was 54.7% among the BC cases compared with 46.6% among controls, and the P value for the distribution of menopause status between the cases and controls was 0.011.The characteristics of the cases and controls were listed in P>0.05). A multivariate logistic regression model demonstrated that individuals carrying the A allele, GA or AA genotypes presented a significantly elevated risk of BC compared with those carrying the G allele or GG genotypes after adjusting for age and menopausal status . Meanwhile, under dominant, recessive, and additive models, significant associations were also found for SNP rs2046210, with ORs equal to 1.42, 1.49, and 1.32 , respectively.The genotype data of rs2046210 in the cases and controls are shown in P = 0.029) and 1.38(P = 0.009) respectively.We then stratified the data according to menopausal status and ER status. The results demonstrated that rs2046210 was associated with an elevated risk of BC in an allelic model among both pre- and post-menopausal individuals. The positive association of this SNP with BC risk was also found for both ER positive and ER negative women with adjusted ORs equal to 1.27 compared to G allele (P<0.001), 1.33  and 1.21  respectively. Significant associations between rs2046210 and BC risk were also observed in the recessive model  and the additive model  in this meta-analysis.As shown in G allele . Genotyptau2 (tau2  = 0.0073), and then we conducted a series of univariate model by adding single covariates including ethnicity of population, study design, study method, sample size, and source of control. In the univariate analyses, we found that the tau2 value reduced to 0.0014 (adjusted R2 = 81.04%) in the model of ethnicity, suggesting that ethnicity could explain 81.04% of the heterogeneity across studies in this allelic model. Then the stratified analyses by ethnicity were further carried out , therefore, the further meta-regression was carried out and it revealed that the source of control could explain 53.61% of heterogeneity. After excluding the multicenter research reported by Steven et al I2 = 21.6%, P = 0.202).When we subsequently stratified the data by ER and menopausal status, the between-study heterogeneity was obvious, but it was reduced notably after further stratifying by ethnicity. The pooled ORs of A VS. G were 1.23 in the ER negative population and 1.12 in the ER positive population. After comparing to cases with ER positive BC, the OR (95%CI) for ER negative BC was 1.11 for allelic model of A VS.G, which indicated that the association was stronger for ER negative BC than ER positive BC. Meanwhile, the positive association of this SNP with BC risk was also found in both pre- and post-menopausal women , however, no stronger association was found in post-menopausal cases by comparison with pre-menopausal counterparts (P = 0.706).To investigate the potential sources of between-study heterogeneity under allelic model of A VS. G, meta-regression analyses were performed. A empty regression was initially run to estimate the baseline value for ried out . In Asiaried out . It demoSince significant heterogeneity across studies existed in all genetic models of overall population and in allelic model of European population, we carried out sensitivity analyses to evaluate the effect of each study on the pooled estimate under a random-effects model by removing each study sequentially. As shown in Cumulative meta-analyses were carried out in all genetic models via an assortment of studies in chronologic order. As shown in A funnel plot  and EggeThis study demonstrated a significant association between rs2046210 and an increased risk of BC in a Han Chinese population. The subsequent meta-analysis based on 36 studies consisting of 53,379 cases and 55,493 controls also confirmed the strong association under all genetic models in an overall population. To the best of our knowledge, this is the first meta-analysis seeking to clarify the association between this polymorphism and BC risk, and the sensitivity and cumulative analyses confirmed that the positive finding was stable and the precision of estimation was progressively boosted as more studies were involved. These results clearly revealed the role of this polymorphism, which is near the ESR1 gene, in BC susceptibility.In the overall meta-analyses, all genetic models presented significant heterogeneity. However, the heterogeneity had been mostly explained by the ethnicity of study population according to the result of meta-regression analyses. After being stratified by ethnicity, it demonstrated that this polymorphism had a significant association with BC risk in Asians and only a weaker and unstable association in Europeans. Meanwhile it could not be validated in Africans. The strength of the association with rs2046210 varies greatly across ethnic groups. One probable reason is the considerable differences in genetic architecture across ethnic SNPs. Another plausible hypothesis suggests that rs2046210 is only a marker SNP of causative variants and resides in different linkage disequilibrium (LD) patterns among the three ethnic populations.Intriguingly, in further analysis, we found that this association was more significant in ER negative than in ER positive BC. Two recent interesting studies Considering the relative vicinity of rs2046210 to the ESR1 gene, it was speculated that the SNP itself or causal variants in LD with it might alter ESR1 gene expression, thus affecting the susceptibility to BC. However, the functional genomic analyses and in vitro functional experiments conducted by Cai et. al In conclusion, our case-control study and the subsequent meta-analysis effectively corroborated the impact of rs2046210 near the ESR1 gene on BC risk, and showed that the polymorphism had a larger effect on Asians than on Europeans or Africans. However, the function of this SNP is still unclear; future fine-mapping of the BC susceptibility loci tagged by rs2046210 is warranted and the underlying biological mechanism of this polymorphism still needs further investigation.Figure S1Flow diagram of the study selection procedure.(TIF)Click here for additional data file.Figure S2Funnel plot for publication bias test.(TIF)Click here for additional data file.Table S1PRISMA Checklist.(DOC)Click here for additional data file.Table S2Sensitivity analysis of allelic model for Europeans.(DOC)Click here for additional data file.


P<5×10−8) association with disease risk: BST1, CCDC62/HIP1R, DGKQ/GAK, GBA, LRRK2, MAPT, MCCC1/LAMP3, PARK16, SNCA, STK39, and SYT11/RAB25. In addition, we identified novel evidence for genome-wide significant association with a polymorphism in ITGA8 . All meta-analysis results are freely available on a dedicated online database (www.pdgene.org), which is cross-linked with a customized track on the UCSC Genome Browser. Our study provides an exhaustive and up-to-date summary of the status of PD genetics research that can be readily scaled to include the results of future large-scale genetics projects, including next-generation sequencing studies.More than 800 published genetic association studies have implicated dozens of potential risk loci in Parkinson's disease (PD). To facilitate the interpretation of these findings, we have created a dedicated online resource, PDGene, that comprehensively collects and meta-analyzes all published studies in the field. A systematic literature screen of ∼27,000 articles yielded 828 eligible articles from which relevant data were extracted. In addition, individual-level data from three publicly available genome-wide association studies (GWAS) were obtained and subjected to genotype imputation and analysis. Overall, we performed meta-analyses on more than seven million polymorphisms originating either from GWAS datasets and/or from smaller scale PD association studies. Meta-analyses on 147 SNPs were supplemented by unpublished GWAS data from up to 16,452 PD cases and 48,810 controls. Eleven loci showed genome-wide significant ( http://www.pdgene.org) which provides an exhaustive account of all published genetic association studies in PD. One particularly useful feature is the calculation and display of up-to-date summary statistics of published data for overlapping DNA sequence variants (polymorphisms). These meta-analyses revealed eleven gene loci that showed a statistically very significant  association with risk for PD: BST1, CCDC62/HIP1R, DGKQ/GAK, GBA, LRRK2, MAPT, MCCC1/LAMP3, PARK16, SNCA, STK39, SYT11/RAB25. In addition and purely by data-mining, we identified one novel PD susceptibility locus in a gene called ITGA8 . We note that our continuously updated database represents the most comprehensive research synopsis of genetic association studies in PD to date. In addition to vastly facilitating the work of other PD geneticists, our approach may serve as a valuable example for other complex diseases.The genetic basis of Parkinson's disease is complex, i.e. it is determined by a number of different disease-causing and disease-predisposing genes. Especially the latter have proven difficult to find, evidenced by more than 800 published genetic association studies, typically showing discrepant results. To facilitate the interpretation of this large and continuously increasing body of data, we have created a freely available online database (“PDGene”:  SNCA, LRRK2, PARK2, and PINK1 (for review see ref. VPS35 and EIF4G1SNCALRRK2MAPTGBAParkinson's disease (PD) is the second most common neurodegenerative disease with a prevalence of ∼1% over 60 years of age GAK, BST1, and PARK16, see http://www.pdgene.org).During the last few years, genome-wide association studies (GWAS) st 2011 (available upon request from the authors). At that time, PDGene included details on 828 individual studies across more than 50 different countries and six continents reporting on 3,382 polymorphisms in 890 genetic loci. Data for more than 2,000 SNPs were supplemented by results derived from up to three publicly available GWAS datasets P values of ≤0.1 in these initial meta-analyses were provided by researchers of all remaining currently published Caucasian GWAS datasets ITGA8 after addition of these data, we obtained additional data from the same GWAS datasets on ∼1,400 SNPs in the chromosomal region encompassing ITGA8 . Finally, independent replication data in Caucasian and Asian populations from the GEO-PD consortium http://www.pdgene.org/largescalemeta.asp), where they are cross-linked to a customized and fully browsable track on the UCSC Genome Browser.The results of this research synopsis are based on a freeze of the PDGene database content on March 31The PDGene meta-analyses of the 867 core polymorphisms were based on a median of 7,680 subjects . Additional meta-analyses were performed after stratification for Caucasian and Asian ancestry  yielded summary ORs suggesting a genome-wide significant (P≤5×10−8) increase or decrease in PD risk in all ethnicities and/or after stratification for ethnic ancestry . The majority of polymorphisms tested in the genome-wide significant loci do not show evidence for publication bias (http://pngu.mgh.harvard.edu/~purcell/gpc/), power was less for a large number of other meta-analyses due to smaller sample sizes and allele frequencies  GAK and SYT11/RAB25 on PD risk in Asians: GAK rs6599388 violated Hardy-Weinberg equilibrium in Asian datasets from the GEO-PD consortium and was thus excluded from further analyses on that ethnic group SYT11/RAB25 chr1:154105678 was excluded from all analyses due to technical reasons in the study by the GEO-PD consortium SYT11/RAB25 and GAK SNPs from the recent GWAS meta-analysis 2≥0.8) in the Japanese GWAS dataset MAPT-H1/H2 haplotype, rs10928513 in ACMSD, and rs7077361 in ITGA8 owing to monomorphicity at these sites ulations . FurtherP>5×10−8), we applied two “credibility” measures for each such result. First, we calculated Bayes factors  assuming an average non-null odds ratio of 1.15, as approximation of a typical “complex disease effect size”, and a spike and smear prior distribution of effects To estimate the epidemiologic credibility of associations with polymorphisms showing sub-genome-wide significant association with PD (HLA locus receiving the best possible grade in the HuGENet criteria (grade A), but more moderate support in the Bayesian analyses (logBF = 4.4). However, the relevance of this assessment needs to be evaluated as the underlying analysis was only based on four GWAS datasets.There was strong epidemiologic support in both assessments for all loci showing genome-wide significant association. This included several additional polymorphisms in these same loci that only showed sub-genome-wide significant association. However, there was no additional sub-genome-wide significantly associated locus that received unequivocally strong support from both credibility assessments . In thisThe PDGene database represents a comprehensive, regularly updated and freely available online research synopsis of genetic association studies in PD. Detailed summaries of the most compelling findings are provided within an easy-to-use, dedicated online framework, displaying forest plots, cumulative meta-analyses, and an up-to-date ranking of “Top Results”. To allow comparison of PDGene results with association findings from other complex diseases and to facilitate their interpretation with respect to functional genetics data, all meta-analysis results have been ported as a customized track onto the UCSC Genome Browser. This will also allow for a integration and visualization BST1, CCDC62/HIP1R, DGKQ/GAK, GBA, ITGA8, LRRK2, MAPT, MCCC1/LAMP3, PARK16, SNCA, STK39, SYT11/RAB25 represent genuine PD risk loci, while the role of several other loci  remains to be determined. The unpublished data aggregated here from various PD genetics groups for selected candidate genes represents the first step towards a systematic meta-analysis across the full GWAS datasets from the same populations. Once completed, the results of this “mega” meta-analysis will be posted on the PDGene database, allowing users to browse the complete results via the customized genome browser track already in place.To the best of our knowledge, our study represents the most comprehensive research synopsis in the field of PD genetics. In addition, it represents the first disease-specific genetic database that allows a systematic and exhaustive inclusion of GWAS data, and may serve as a model for similar databases in other complex genetic diseases. Owing to our multi-pronged data retrieval and analysis protocol we were able to perform meta-analyses on the vast majority of PD risk-gene candidates, including those “featured” as top association results in all published GWAS. In particular, this includes the five novel loci recently featured in the recent GWAS meta-analysis GBA [OR 3.51 in Caucasians], LRRK2 [OR 2.23 in Asians], and SYT11/RAB25 [OR 1.73 in Caucasians], see Of particular interest are loci with unusually large effect sizes. While most loci in PDGene have only small effects on PD risk , for some loci much larger ORs were estimated  is functionally interesting as it is expressed in brain GBA, a gene that was found soley by candidate-gene approaches. Another strength of our study is that it combines genetic data from currently more than 50 different countries allowing a systematic assessment of genetic associations across populations of different ethnic descent. For instance, these analyses suggest that variants in BST1, LRRK2, the PARK16 locus, and SNCA show genome-wide significant association with PD risk in both Caucasian and Asian-descent samples. Furthermore, the recently described Caucasian GWAS loci CCDC62/HIP1R, MCC1, and STK39The strength of our approach is further exemplified by the identification of genome-wide significant association between disease risk and a SNP in ITGA8 as a novel potential PD risk locus. Our quantitative approach to data integration across a multitude of different study designs can be readily scaled to include large-scale resequencing efforts that will emerge over the coming years, making the complex field of PD genetics accessible to a broad range of investigators.In summary, we have created a continuously updated online resource for genetic association studies in the field of PD. Synthesizing essentially all available data in the field led to the identification of Note that the following section only provides a brief summary of the methods applied to our study. A much more detailed description can be found in ITGA8 from the Japanese GWAS dataset For inclusion in PDGene, a study has to meet three criteria: 1) It must evaluate the association between a bi-allelic genetic polymorphism  and Parkinson's disease (PD) risk in datasets comprised of both affected  and unaffected individuals; 2) it must be published in a peer-reviewed journal; 3) it must be published in English. For this manuscript, we also included data on ten SNPs generated in the GEO-PD Consortium datasets In brief, genetic association data of the following studies were excluded from the meta-analyses see .st, 2011, yielded 27,210 articles, which were screened for eligibility using the title, abstract, or full-papers, as necessary. Additional screening of bibliographies in reviews, published meta-analyses, and original genetic association studies were also performed. Overall, full text versions of 1,534 articles were obtained. Following the inclusion and exclusion criteria outlined above, 828 articles were included in PDGene until March 31st 2011 , and assessed the credibility of each at least nominally significant meta-analysis result by calculating Bayes factors ="logBF”) Random-effects allelic meta-analyses publicly available GWAS data P≤0.1), we obtained additional data from all currently published, but not publicly available GWAS datasets, further decreasing a potential impact of small-study bias/publication bias. Thirdly, we directly assessed the evidence for small study bias by applying a recently proposed regression test P<0.05) meta-analysis results. The results of these analyses are fully displayed in This is of particular importance in meta-analyses of published association data and was carefully addressed here: First, we added st, 2011). Genotype data were cleaned using standard procedures, followed by imputation of untested genotypes (using reference panels from HapMap and the 1000 Genomes Project), and association analyses incorporating imputation uncertainty (case-control datasets only), age, sex, and population stratification. Overall, this procedure led to a total of 7,723,931 unique SNPs, 7,123,920 of which were present in at least two, and 711,271 in at least three datasets. Meta-analyses .After completion of all data-management and analysis steps, all study-specific variables, genotype data (except for GWAS), and meta-analysis plots are posted on a dedicated, publicly available, online adaptation of the PDGene database using the same software and code as our databases for Alzheimer's disease The database software can easily be ported to other genetically complex diseases and will be made available on a collaborative basis to interested researchers upon request.Figure S1P-values .QQ plots showing the distribution of expected versus observed P-values for the GWAS-only meta-analysis results. Analyses were performed using the METAL software ref. . The excP-values , panel 1(TIF)Click here for additional data file.Figure S2st 2011 datafreeze. Study-specific allelic odds ratios  and 95% confidence intervals  were calculated for each included dataset. The summary OR and CI was calculated using random-effects models (grey diamond). Whenever multiple polymorphisms showed genome-wide significant association in the same locus, only the variant with the smallest P-value is listed here for meta-analysis results after stratification for Caucasian and Asian ancestries. For a complete list of meta-analyses performed for the datafreeze, see http://www.pdgene.org). I2 = estimate of percentage of between-study heterogeneity that is beyond chance, “excl initial” = summary OR and 95%CI after meta-analysis after exclusion of the initial study, C = Caucasian ancestry, A = Asian ancestry, H = Hispanic descent, D = African descent, “•” = initial study (applies to candidate-gene studies), “†” = no data provided or data was not eligible for inclusion in meta-analysis, “‡” = study excluded due to overlap, “#” = HWE violation in controls  with PD susceptibility in the March 31(PDF)Click here for additional data file.Figure S3ITGA8 region including at least four independent datasets. SNPs are color-coded based on linkage disequilibrium (r2) estimates from the CEU 1000G dataset (release June 2010). All LD estimates refer to the most significantly associated SNP rs7077361. SNPs color-coded in grey indicate missing LD estimates in the CEU dataset. Recombination rates were estimated based on the CEU dataset, and are displayed as blue line in the background. Gene annotations are based on RefSeq and the UCSC Genome browser. Locus plots were generated using the LocusZoom Stand-alone package .Locus plot of the ITGA8 region on chromosome 10p13 . The figure displays association results for ∼1,400 SNPs in the (TIF)Click here for additional data file.Figure S4Forest plots of fixed-effect meta-analyses for SNP rs6723108 in the ACMSD/TMEM163 locus and chr6:32609909 in the HLA locus. Symbols are the same as for (TIF)Click here for additional data file.Table S1st 2011 datafreeze using random-effects allelic models. Random-effects allelic meta-analyses were performed on polymorphisms for which four or more independent datasets were available. Meta-analyses after stratification for different ethnic descent were performed if at least three independent datasets were available in the respective stratum (applicable only to samples of European and Asian descent). Each nominally significant meta-analysis result (P<0.05) was graded according to the HuGENet interim criteria. For details on how these criteria are applied, see P<0.05), Regr = evidence for small-study/publication bias using a modified regression test Click here for additional data file.Table S2Investigation of the extent of statistical inflation assuming sample overlaps of 1%, 5%, and 10% across cases and controls in datasets originating from the same countries. Hypothetical sample overlap across datasets was assumed between different candidate-gene/replication studies and between candidate-gene/replication studies and GWAS datasets if they originated from the same country. These analyses were performed applying random-effects models and adding the sum of weighted co-variances of overlapping datasets to the overall study variance (see ref. (DOC)Click here for additional data file.Text S1Supplementary material. This file includes supplementary methods and references as well as the list of members of the GWAS consortia, the GEO-PD Consortium, and consortia-specific acknowledgements.(PDF)Click here for additional data file.


Recently, many studies have reported that the SNP+45(T>G) and SNP+276(G>T) polymorphisms in the adiponectin gene are associated with type 2 diabetes (T2DM) in the Chinese Han population. However, the previous studies yielded many conflicting results. Thus, a meta-analysis of the association of the adiponectin gene with T2DM in the Chinese Han population is required. In the current study, we first determined the distribution of the adiponectin SNP+276 polymorphism in T2DM and nondiabetes (NDM) control groups. Our results suggested that the genotype and allele frequencies for SNP+276 did not differ significantly between the T2DM and NDM groups. Then, a meta-analysis of 23 case-control studies of SNP+45, with a total of 4161 T2DM patients and 3709 controls, and 11 case-control studies of SNP+276, with 2533 T2DM patients and 2212 controls, was performed. All subjects were Han Chinese. The fixed-effects model and random-effects model were applied for dichotomous outcomes to combine the results of the included studies. The results revealed a trend towards an increased risk of T2DM for the SNP+45G allele as compared with the SNP+45T allele  in the Chinese Han population. However, there was no association between SNP+276 and T2DM . The results of our association study showed there was no association between the adiponectin SNP+276 polymorphism and T2DM in the Yunnan Han population. The meta-analysis results suggested that the SNP+45G allele might be a susceptibility allele for T2DM in the Chinese Han population. However, we did not observe an association between SNP+276 and T2DM. Diabetes mellitus comprises a group of metabolic disorders that are characterized by chronic hyperglycemia. Type 2 diabetes (T2DM) and its complications impose a tremendous burden both on individuals with diabetes and on the health care system.Adiponectin is an important adipocytokine that is secreted by adipocytes and plays a key role in the regulation of insulin sensitivity and glucose homeostasisThe Chinese population comprises 56 ethnic groups, of which Han is the largest . The Han are descended from the Huaxia tribe who lived in the area of the Yellow River, and then migrated to the area of the Yangtze River. The Han have now spread throughout the country and live in different regions of China. Many studies that investigated the association in the Chinese Han population between T2DM and SNPs in the adiponectin gene have been reported recently The aim of the current study was first to evaluate the association of SNP+276 with T2DM in the Han population in Yunnan Province, in the southwest of China. Then, we combined our data with those of 25 previous studies for a carefully designed meta-analysis to investigate the association of the SNP+45 and SNP+276 polymorphisms in the adiponectin gene with T2DM in the Chinese Han population. Our study will provide a more thorough evaluation of the significance of the association of the SNP+45 and SNP+276 polymorphisms with T2DM in the Chinese Han population.The clinical characteristics of the enrolled subjects are presented in 2 = 1.59, P = 0.45). After adjusting age and gender, the genotype frequencies for SNP+276 also showed no significant differences between the T2DM and NDM groups . In addition, the allele frequencies for SNP+276 showed no significant differences between the T2DM and NDM groups .SNP+276 conformed to HWE in both the T2DM group and the NDM group (P = 0.72 and P = 0.34), respectively. The allele and genotype frequencies for SNP+276 are shown in The initial search strategy to identify association studies for T2DM and SNPs in the adiponectin gene yielded a total of 262 potentially relevant references among all the databases, 146 of which were overlapping. After subsequent screening, 26 studies were identified for recruitment in the light of the inclusion criteria.2 = 84.6% for SNP+45 and Pheterogeneity <0.01, I2 = 76.9% for SNP+276. Therefore, the random-effects model (I-V heterogeneity) was used to calculate the pooled ORs and 95% CI for both SNPs. Overall, there was a trend towards an increased risk of T2DM for the SNP+45G allele as compared with the SNP+45T allele . However, there was no trend towards an increased risk of T2DM for the SNP+276T allele as compared with the SNP+276G allele .Begg's funnel plot and Egger's test were performed to determine whether the literature showed a publication bias. The Begg's funnel plots were symmetrical by visual inspection , and neiA sensitivity analysis was performed by omitting one study at a time and calculating the pooled ORs for the remaining studies. This analysis showed that none of the individual studies influenced the pooled ORs, which ranged from 1.29 (95% CI = 1.08–1.55) to 1.41 (95% CI = 1.19–1.69) for SNP+45, and 0.85 (95% CI = 0.76–0.96) to 0.97 (95% CI = 0.88–1.06) for SNP+276. The sensitivity analysis indicated that the results of the meta-analysis were reliable and stable.The adiponectin gene is located on human chromosome 3q27, where a region identified as a susceptibility locus for metabolic syndrome and T2DM has been reported, and is composed of three exons that span 17 kbTo the best of our knowledge, this is one of the largest systematic reviews of the literature that has used a meta-analysis to study the association between the SNP+45 and SNP+276 polymorphisms and T2DM in Chinese Han populations. The previous meta-analysis included eight papers for SNP+45 and four papers for SNP+276heterogeneity <0.01, I2 = 76.9% for SNP+45 and Pheterogeneity <0.01, I2 = 71.3% for SNP+276. The results from the application of the random-effect models revealed that subjects who carried the SNP+45G allele had a significantly increased risk of T2DM as compared with those who carried the SNP+45T allele . However, there was no trend towards an increased risk of T2DM for the SNP+276T allele as compared with the SNP+276G allele . These results were similar to those of the initial meta-analysis in which all the studies were included.HWE is the principal law in population genetic studies. If a locus conforms with HWE, the samples are representative. In fifteen studies of SNP+45 and nine studies of SNP+276, the genotypes in both the T2DM and NDM groups conformed with HWE. Therefore, a further meta-analysis was performed in which only the studies that conformed with HWE were included. The further meta-analysis data showed that there was heterogeneity among the results of the individual studies, Pheterogeneity <0.01, I2 = 84.6%) and SNP+276 . All of the subjects in the current meta-analysis study were Han Chinese but from different regions and the Han Chinese population is not a genetically homogenous group. Thus, this might explain the significant between-study heterogeneity. The differences in age and gender distributions among the included studies, and differences in sample content might also contribute to the heterogeneity.Heterogeneity is a potential problem when interpreting the results of meta-analysis et al first reported that the SNP45+GG genotype of the adiponectin gene was associated with T2DM in the Japanese populationIn 2002, Hara Hara et al. also reported that the SNP+276GG genotype of the adiponectin gene was associated with T2DM in the Japanese populationThe results of our meta-analysis demonstrated that the SNP+45G allele might be a susceptibility allele for T2DM. However, we could not observe any association of SNP+276 with T2DM. As we know, T2DM is influenced by gene–environment interactions. In addition, many genetic factors, including the adiponectin gene, influence the occurrence of T2DM. Therefore, in order to understand the mechanisms underlying T2DM better, future research should be considered and carried out to explore the effects of gene–gene interactions, environmental factors, and individual genetic background.All participants gave written informed consent. The protocol was in accordance with the Helsinki Declaration, and was approved by the Institutional Review Boards of the Second People's Hospital of Yunnan Province.The study included 202 patients  who were diagnosed with T2DM at the Second People's Hospital of Yunnan Province from December 2006 to September 2010. T2DM was confirmed using the criteria of the World Health Organization from 1999. Patients who were treated with insulin or an insulin secretagogue were excluded from the study. The nondiabetes group (NDM) included 143 subjects  who had no family history of diabetes mellitus and were recruited from an unselected population undergoing routine health checkups at the Second People's Hospital of Yunnan Province. Subjects with diabetes or impaired glucose tolerance were excluded from the NDM group on the basis of an oral glucose tolerance test. In addition, subjects with hypertension or coronary heart disease were also excluded from the study. All participants were ethnic Han by self report.2). Waist to hip ratio (WHR) was calculated as WC divided by HC.Weight, height, waist circumference (WC), and hip circumference (HC) were measured by trained personnel in duplicate and the results were averaged. WC was measured midway between the lower rib margin and the iliac crest. HC was measured at the level of the greater trochanter. Body mass index (BMI) was calculated as weight (kg) divided by the square of height (mVenous blood samples were collected in the morning after the subjects had fasted for 12 hours. Fasting plasma glucose (FPG) was assayed by the glucose oxidase method using a HITACHI 7600-020 Automatic Analyzer. Total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and triglycerides (TG) were determined by enzymatic methods with a HITACHI 7600-020 Automatic Analyzer. Low-density lipoprotein cholesterol (LDL-C) was calculated by using the Friedewald formula. Glycosylated hemoglobin (HbA1c) was determined by immunoturbidimetry with a HITACHI 7600-020 Automatic Analyzer. Fasting serum insulin was measured by radioimmunoassay with a Gamma counter. Insulin resistance was assessed by homeostatic model assessment ×fasting insulin (µU/ml)]/22.5).TM G-50 .Genomic DNA was extracted from peripheral lymphocytes by a standard hydroxybenzene–chloroform method. SNP+276 (rs1501299) was genotyped by the polymerase chain reaction-based restriction fragment-length polymorphism (PCR-RFLP) method. The PCR product was 745 bp and was digested with BmsI into fragments of 523 bp and 222 bp. The digested products were subjected to electrophoresis through a 2% agarose gel, stained with ethidium bromide, and visualized under ultraviolet light. Some of the PCR products were characterized by direct sequencing  using a BigDye Terminator v3.1 Cycle Sequencing Kit  after purification with Sephadexhttp://ihg2.helmholtz-muenchen.de/cgi-bin/hw/hwa1.pl). A χ2 test was used to determine differences in allele and genotype frequencies between T2DM subjects and NDM subjects. The association of SNPs with T2DM was assessed by logistic regression after adjusting for age and gender. A P value of less than 0.05 was considered statistically significant.The allele and genotype frequencies for SNP+276 were calculated by the direct-counting method. Hardy–Weinberg equilibrium (HWE) was tested in both the cases and the controls . The search terms were as follows: ‘adiponectin’ OR ‘APM1’, ‘polymorphism’ AND ‘type 2 diabetes mellitus’, ‘China’ OR ‘Chinese’.To be included in the meta-analysis, studies had to meet all the following criteria: (a) an unrelated case-control design, (b) all subjects were Han Chinese, (c) available genotype and allele numbers or frequencies, (d) published in any language. PCR-single stranded conformational polymorphism (PCR-SSCP) or PCR-RFLP analysis and DNA sequencing were used to examine the mutations in the adiponectin gene. If there were multiple publications from the same group, only the most recent study was included in the analysis.The two authors who conducted the literature search (Yiping Li and Li Shi) also extracted the data from the studies independently. Any disagreement was adjudicated by consensus and by consulting two additional authors (Ying Zhang and Yufeng Yao). Author name, journal and year of publication, region of origin, diagnosis criteria for T2DM, size of case and control groups, and adiponectin SNP loci analyzed were collected. Sample sizes, genotype and allele numbers, and P values for HWE in the T2DM and NDM groups were summarized .http://ihg2.helmholtz-muenchen.de/cgi-bin/hw/hwa1.pl). Then, we compared T2DM cases with controls by using the allele model (A/a) for each SNP. The odds ratios (ORs) and 95% confidence intervals (CI) were calculated to determine the differences in each SNP between the T2DM and NDM groups. The χ2-based Q statistic test was used to assess the between-study heterogeneity2 was also calculated to evaluate the amount of variation that was caused by heterogeneity rather than by chance: higher values of the index indicate the existence of heterogeneityHardy–Weinberg equilibrium (HWE) was tested for all studies included Click here for additional data file.Table S2Comparison of genotypic and allelic distribution of SNP+45 and SNP+276 between type 2 diabetic and nondiabetic subjects.(DOCX)Click here for additional data file.Table S3Characteristcs of case-control studies included in a meta-analysis of the association between SNP+45 of adponectin gene and T2DM.(DOCX)Click here for additional data file.Table S4Characteristcs of case-control studies included in a meta-analysis of the association between SNP+276 of adponectin gene and T2DM.(DOCX)Click here for additional data file.


EPHA2) with the risk for age-related cataract in populations of different ethnic/racial backgrounds, but inconsistent results have been obtained.Recent clinical studies have assessed the association of various polymorphisms on the ephreceptor tyrosinekinase-type A2  might be commonly present in different ethnic/racial populations in association with the age-related cataract risk.EPHA2 polymorphisms with the risk for age-related cataract. The polymorphisms that were assessed in all eligible studies were analyzed for their association with the risk for age-related cataract using different models.The PubMed and Web of Science databases  were searched for clinical studies on the association of Three studies were identified, which were conducted, respectively, on white Americans in the Unites States and on Asians in Indian and China. The polymorphism, rs3754334, was the only one studied in all these three studies and was therefore the focus of this meta-analysis. No publication bias or heterogeneity was found. Our analysis results demonstrated that rs3754334 was associated with the risk of any cataracts in the recessive  and Codominant  models, but its association with cortical or nuclear phenotype of age-related cataract was not evident.EPHA2 gene that is commonly associated with the risk for age-related cataract in different ethnical and geographical populations.Polymorphism, rs3754334, might be a variant on the  Although cataracts can be removed surgically, this treatment option may not be feasibly available to a large proportion of patients in resource-limited countries or regions with inadequate surgical services and high operation costs The development of age-related cataract is a complex process, involving multiple factors. In the past few decades, extensive research efforts have been devoted to identifying risk factors and characterizing their nature and specific roles in the pathogenesis of age-related cataract worldwide. It is anticipated that identification and characterization of the major risk factors for age-related cataract may help doctors adopt individualized preventive and treatment measures. Although a spectrum of demographic, environmental, life style-associated, disease-related and miscellaneous factors have been proposed as risk factors for cataract, no associations between cataract and these putative risk factors except for increasing age have been consistently demonstrated EPHA2) is a member of the subclass A of the Eph subfamily of receptor tyrosine kinases EPHA2 gene encodes a 976 amino acid, type-1 transmembrane protein with an extracellular NH2-terminal domain and a cytoplasmic COOH-terminal domain EPHA2 gene with the risk for various subtypes of cataract has been assessed. However, the results from studies on different racial/ethnical populations in different geographic regions worldwide are inconsistent EPHA2 SNPs and the risk for age-related cataract commonly present in different racial/ethnical population groups.Eph-receptor tyrosine kinase-type A2 (EPHA2” or “Eph-receptor tyrosinekinase-type A2” and “genetic variant” or “polymorphism”. Articles that fulfilled the following four inclusion criteria were selected: (a) evaluation of the association between polymorphisms in the EPHA2 gene and age-related cataract risk, (b) retrospective case-control studies or prospective cohort studies, (c) availability of data sufficient to estimate an odds ratio (OR) with a 95% confidence interval (95% CI), (d) publication in the English language with full text. There were no restrictions on sample size in the search. Clinical studies cited both in the selected articles and in relevant review papers were also retrieved. In cases of overlapping, only earliest studies were used. In cases of duplicated publication, only studies with the largest sample size were used.The electronic databases of PubMed and Web of Science were last searched on December 1, 2012 using the following search terms: “cataract”, “The following variables were extracted from each of the retrieved articles: first author's family name, publication year, country, numbers of cases and controls, ethnicity, phenotypes and genotypes. Phenotypes were categorized as cortical cataract, nuclear cataract, and any cataracts.This extraction was performed by two of the authors (P. Zhou and J. Yang) independently. Disagreements were resolved by discussions between the two authors. If no consensus could be reached, a third investigator (Y. Lu) made the final decision.EPHA2 gene. Four crude ORs and their 95% CIs for the association between the SNP(s) being evaluated and age-related cataract were calculated: (1) heterozygous versus common homozygous carriers, (2) rare homozygous versus common homozygous carriers, (3) rare allele carriers versus common homozygous carriers (dominant model), and (4) rare homozygous versus common allele carriers (recessive model). Heterogeneity among the included studies was assessed by the Q-test The primary measure of this meta-analysis was the strength of the association of age-related cataract with the SNP(s) of interest on the The statistical analysis software Stata/SE version 10.0  was used. In all tests, differences were considered significant when P<0.05.EPHA2 gene for their associations with age-related cataract. Among these SNPs, rs3754334 was the only one that was studied in all the three included studies and had adequate information for a meta-analysis. As a result, we focused on rs3754334 in this study. Summarized in Three studies met the inclusion criteria and were included in this meta-analysis  among those evaluated in previous studies that is truly associated with the risk for age-related cataract. To this end, we pooled the data from three independent clinical studies As the interest in the role of genetic component in the development of cataract is growing exponentially over the past two decades, variations have been identified as putative causes of cataracts in more than 35 loci within the human genome EPHA2 gene is truly associated with the risk for the development of age-related cataract across populations of different ethnic/racial backgrounds. Nevertheless, this does not mean that the association of other polymorphisms on the EPHA2 gene assessed in the individual studies with the age-related cataract risk is not true. It might be very likely that those associations demonstrated in the individual studies would become stronger if they were included in the meta-analysis. Unfortunately, however, no polymorphisms other than rs3754334 were assessed in all the three included studies, making the analysis of other polymorphisms impossible in this study.Our analyses showed that the polymorphism rs3754334 was associated with the risk for any age-related cataracts but neither cortical nor nuclear cataract. This result was not totally consistent with those presented individually in the three individual studies included in this meta-analysis. In the US study, minor allele frequencies for rs3754334 in cataract cases were only slightly higher than those in controls (34% vs 28%) with no significant allelic p values obtained EPHA2, which leads to 2874C->T in the EPHA2 mRNA. However, this C->T switch does not change the protein sequence and thus rs3754334 is not a functional polymorphism. It might be possible that the rs3754334 mutation results in changes in the configuration of the EPHA2 protein, thereby increasing the risk of age-related cataract development. Nevertheless, this has yet to be further elucidated.The polymorphism rs3754334 is a synonymous polymorphism in Some limitations of this meta-analysis should be acknowledged. First, although the available data on rs3754334 comprised 4776 cases and 3116 controls, no association was found between this SNP and cortical cataracts. Therefore, additional study is warranted to determine the true association rs3754334 with the risk for cortical cataract. Second, the primary outcome measure was calculated based on individual unadjusted ORs. This might affect the evaluation precision of the study. Finally, the lack of individual data in each study prevented more detailed analyses on combined effects of SNP–SNP or gene–environment factors.EPHA2 gene of populations of different racial backgrounds and associated with the age-related cataract risk, in addition to the polymorphisms individually demonstrated in the three included studies. Further investigations are warranted to validate the role for rs3754334 in the development of age-related cataract and the underlying mechanism(s).In summary, this meta-analysis of three individual studies on different ethnic/racial populations in different continents has shown that rs3754334 might be a polymorphism that is commonly occurring in the Checklist S1PRISMA 2009 checklist.(DOC)Click here for additional data file.