P = 0.011). The association was stronger between T allele and the risk of anti-double-stranded DNA (dsDNA)-positive systemic lupus erythematosus . The meta-analyses included 8648 systemic lupus erythematosus patients and 10947 controls. rs2431697 T allele had an overall OR of 1.262  under fixed-effects model. After stratified by ethnicity, I2 reduced from 24.3 to 0 %. T allele had an OR of 1.213  in European descendant and 1.365  in Asian under fixed-effects model. Data on women were also extracted, and T allele had an OR of 1.337  under random-effects model. The pooled ORs were not influenced by each study in sensitivity analyses. There were no publication biases observed in these analyses. The results from our case-control study and the meta-analyses indicate that rs2431697 T allele significantly associates with the increased risk of systemic lupus erythematosus.rs2431697 is located on 5q33.3, between pituitary tumor-transforming gene 1 and miR-146a. Several studies have estimated the association between rs2431697 and systemic lupus erythematosus risk. However, the results were inconsistent. A case-control study was carried out to explore the association between rs2431697 and systemic lupus erythematosus risk in a central Chinese population. Meta-analyses combining present with previous studies were conducted to further explore the association. Our case-control study included 322 cases and 353 controls. rs2431697 T allele was associated with increased risk of systemic lupus erythematosus (odds ratios (ORs) = 1.461, 95 % confidence intervals (CI) 1.091–1.957, The online version of this article (doi:10.1007/s10067-015-3045-4) contains supplementary material, which is available to authorized users. SLE mainly affects women, especially during childbearing years [ 5.8–29)  and the  5.8–29) . Many evRecent genome-wide association studies (GWAS) have provided us many SLE susceptibility single-nucleotide polymorphisms (SNPs). Besides those classic immunology molecule-associated SNPs, there are also many other new SNPs . rs24316SLE sample composed of 322 unrelated Han Chinese individuals  from Hubei Province, China. The mean age was 36 . All the patients fulfilled the SLE diagnosis criteria of American College of Rheumatology (1997). SLE-associated autoantibodies  were detected by Western blot/EUROLINE-WB Test Systems  in the department of Laboratory Medicine, Union Hospital, Tongji Medical College. Healthy Han Chinese included 353 individuals  recruited from the Medical Examination Center, Union Hospital. The mean age was 39 . All the healthy individuals had no evidence of SLE or other autoimmune diseases. All individuals gave informed consent. The study was carried out following the Declaration of Helsinki and approved by the Ethics Committee of Union Hospital, Tongji Medical College, Huazhong University of Science and Technology.Genomic DNA was extracted and purified from peripheral blood with DNA Extractor WB Kit  according to the product description. rs2431697 polymorphism was determined based on polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. A 260-bp DNA fragment around rs2431697 was amplified with the primer pair: sense primer: 5′-AGAGGGGGTGAAAGAAGGAA-3′ and antisense primer: 5′-TTCTCAGTGCCAATGTGAGG-3′. The reaction mixtures contained 10 ng genomic DNA, 10 pmol of each primer, and double-diluted Taq 2× Master Mix  in a total 20-μl volume. The reactions were carried out in a T3 thermocycler . The reaction conditions were as follows: denaturation at 94 °C for 5 min, followed by 35ccycles of denaturation at 94 °C for 30 s, annealing for 1 min at 57 °C and extension at 72 °C for 45 s, and a final extension at 72 °C for 5 min. PCR products were subsequently digested by Taq I  at 65 °C for 2 h and separated on a 3 % agarose gel. The rs2431697 T allele yielded 61- and 199-bp fragments, and C allele yielded a single 260-bp fragment.P (two-tailed) <0.05. All analyses were performed by SPSS (Version 12.0).Hardy-Weinberg equilibrium was analyzed by the chi-square goodness of fit test for genotypes in the control group. The differences of allele and genotype frequencies between SLE patients and health controls were compared by the chi-square test. Unconditional multivariate logistic regression analysis was used to estimate odds ratios (ORs) and 95 % confidence intervals (CI) for the effect of rs2431697 on SLE risk, adjusted for age and sex. PS: Power and Sample Size Calculation version 3.0  was usedTo further estimate the association between rs2431697 and the risk of SLE, a meta-analysis according to the guideline of Preferred Reporting Items for Systemic Reviews and Meta-Analysis (PRISMA) statement was performed. Studies were searched and retrieved through PUBMED and EMBASE without language restriction. The search keywords were “rs2431697,” “miR-146a,” or “pttg1” or “pituitary tumor-transforming protein 1” in combination with “systemic lupus erythematosus”. Results were limited in studies of humans and not experiments designed. The reference lists of included articles and related review articles were manually searched. The final search was carried out on 8 December 2014. Retrieved studies were restricted in publication type of article or article in press and eligible if they were case-control designed and if they provided (in the primary paper or by email request) the frequencies of alleles and/or genotypes for rs2431697 in SLE cases and healthy controls. Data that overlapped with others was excluded. Two authors  independently read and extracted data. A third author helped to decide if controversy occurred. The following information was extracted: name of first author, year of publication, ethnicity, matching variable, sizes of cases and controls, numbers or frequencies of alleles, or genotypes in cases and controls.For each included study, Hardy-Weinberg equilibrium in controls was deduced or extracted from the primary papers. Pooled ORs and 95 % CIs of the T allele in overall populations, ethnicity-stratified populations, and female populations were estimated. Pooled ORs and 95 % CIs of rs2431697 genotypes, dominant genetic model, and recessive genetic model in overall populations and female populations were also assumed.Q test and I2 value. Random-effects model was used if the P value of Q test was less than 0.1 or I2 value was larger than 50 %. Otherwise, fixed-effects model was carried out. Sensitivity analysis was performed to assess the influence of each study. Publication bias was estimated by funnel plot [Heterogeneity of the eligible studies was assessed by Cochran’s nel plot  and Eggenel plot . All staP = 0.8041). The distribution of rs2431697 T allele was significantly increased in SLE patients compared with controls . There were no differences found in genotype distribution between SLE patients and controls, except for the recessive model   (Table P = 0.007).Considering the gender disposition of SLE, data on women were extracted for separated analysis. Significant statistical difference was seen in T allele frequencies between SLE patients and healthy controls . In anti-dsDNA-negative patients, rs2431697 T allele frequency was 0.84; there was no statistic difference between SLE patients and healthy controls . Similar results were also observed when data were subgrouped by anti-sm condition.Anti-dsDNA and anti-sm are SLE-specific autoantibodies. SLE patients were subgrouped by the existence or inexistence of anti-dsDNA and anti-sm autoantibodies. There were 123 anti-dsDNA-positive and 171 anti-dsDNA-negative individuals included in this case-control study. The frequency of rs2431697 T allele in anti-dsDNA-positive patients was 0.91. The T allele was substantially increased in anti-dsDNA-positive patients compared with healthy controls  , but not CT versus CC . Increased SLE risk was also observed in dominant and recessive models  in European descendant and 1.365  in Asian , and random-effects model was used   Fig. . The pooSensitivity analysis showed that the association of rs2431697 T allele with SLE remained significant after removing any one study in the overall and women-only meta-analysis . We further confirm this association with a meta-analysis that includes 8648 SLE patients and 10,947 controls . The current data also suggest that association between rs2431697 and SLE risk is under recessive model and related with autoantibody-positive condition.Benefitting from the technology of GWAS, large numbers of SLE-associated SNPs were discovered . The SNPThe SNP rs2431697 is located in an intergenic region with 24.23 kb from downstream of PTTG1 gene and 15.3 kb from upstream of miR-146a . This miThe effect size was slightly higher in our case-control study. Our SLE patients were recruited from rheumatology inpatient department in a large metropolitan health center. A big proportion of inpatients entering this kind of health center in China is from rural areas and has more severe disease conditions. Our cohort may be biased toward the more severe patients. However, the association between rs2431697 and disease severity is yet to be evaluated.A previous study has shown that some gene polymorphisms were specifically associated with the risk of autoantibody-positive rheumatoid arthritis . Since tI2 from 24 to 0 %). It suggests that ethnicity is the main source of heterogeneity. The pooled OR strongly indicated that the T allele of rs2431697 is an SLE risk factor both in Asian and in European descendant. Studies based on more ethnic populations are needed to improve this result.The prevalence of SLE was different across different populations . Both enThe T allele of rs2431697 was first suggested to be associated with SLE susceptibility in women , female There are some limitations in this study. Firstly, the sample size of our case-control study is not large enough, resulting in moderate statistical power (0.724). However, the allele frequency in our study is similar to another large Chinese population-based results  and alsoIn conclusion, this study adds to the growing evidence of the effect of rs2431697 on SLE risk. Our meta-analysis verified a significant association between rs2431697 T allele and SLE risk in Asian and European descendant populations. Our case-control study also indicated that rs2431697 T allele was associated with the risk of SLE with anti-dsDNA positive but not negative condition. Experimental data are expected to directly demonstrate the pathophysiological mechanism of rs2431697 in SLE risk.Online Resource 1(PDF 187 kb)Online Resource 2(PDF 176 kb)


P = 0.036 and 0.026, SNP). TT genotype carriers showed slightly lower Brief Assessment of Cognition in Schizophrenia- (BACS-) derived working memory performance than G carriers . In the meta-analysis, we observed a significant association between rs1625579 and schizophrenia under different genetic models . The results of our study and meta-analysis provide convincing evidence that rs1625579 is significantly associated with schizophrenia. Furthermore, the miR-137 polymorphism influences the working memory performance of schizophrenic patients in a Chinese Han population.Both genome wide association study (GWAS) and biochemical studies of Caucasian populations indicate a robust association between the miR-137 genetic variant rs1625579 and schizophrenia, but inconsistent results have been reported. To assay the association between this variant and schizophrenia, we genotyped 611 schizophrenic patients from Southern Chinese Han population for the risk single nucleotide polymorphism (SNP) rs1625579 using the SNaPshot technique and compared the clinical profiles of different genotypes. Additionally, a meta-analysis was performed using the combined sample groups from five case-control publications and the present study. Both the genotype and allele distributions of the rs1625579 SNP were significantly different between patients and controls ( Over haHsa-miR-137, as a brain-enriched micro-RNA, has important roles during neurogenesis, including the proliferation and differentiation of neural stem cells, the regulation of dendritic morphogenesis, and synaptic plasticity , 7, 8. FSince the publication of the 2011 GWAS study , many suWe recruited 611 schizophrenic patients and 628 healthy controls from the affiliated hospital of Guangdong Medical College. All patients underwent a standardized battery of examinations, including family history, extensive drug and alcohol assessment, physical and neurological examination, and laboratory tests to exclude substance-induced psychotic disorders or psychosis caused by general medical condition. The diagnosis was assigned independently by two experienced senior psychiatrists based on the Diagnostic and Statistical Manual of Mental Disorders IV (DSM-IV). Psychotic symptoms were evaluated in accordance with structured interviews for the Positive and Negative Symptom Scale (PANSS). The healthy controls were recruited from the Medical Center of the affiliated hospital of Guangdong Medical College. Based on unstructured interviews, participants who had a personal or family history of major psychiatric disorders, serious somatic illnesses, and substance abuse were excluded. The patients and controls were comparable in age and sex distribution . The stuμL reaction composed of 1 × GC Buffer, 3.0 mM Mg2+, 0.3 mM dNTPs, 1 U of HotStarTaq polymerase , 1 μL of template DNA , and 2 μL of PCR primers. Amplification was performed with the following program: 2 min at 95°C, followed by 11 cycles of 94°C for 20 s, 65°C ± 0.5°C/cycle for 40 s, and 72°C for 1.5 min, and then 24 cycles consisting of 94°C for 20 s, 59°C for 30 s, and 72°C for 1.5 min, with a final extension step at 72°C for 2 min. The extension primer was 5′-TTTTTTTTTTTTTTTTTTTTTAAACAAGGGAAATGTTAATCACAATTA-3′. The single-nucleotide primer extension reaction was conducted using the ABI PRISM SNaPshot Multiplex Kit Protocol . Then, 0.5 μL of the purified single base extension products was mixed with 9 μL of Hi-Di formamide and 0.5 μL of GeneScan-LIZ 120 internal size standard. After a denaturing step for 2 min at 95°C followed by cooling to 5°C, the mixture was further analyzed by capillary electrophoresis using an ABI Prism 3130xl Genetic Analyzer . The data were analyzed using GeneMapper 4.1 .DNA from blood samples was extracted using the Blood DNA Kit . SNP rs1625579 was genotyped using the SNaPshot technique with polymerase chain reaction (PCR) primers 5′-TTTAGTCAACATTTGCATTTGGAAGC-3′ and 5′-CAACAGATTCCAAAGGTCTCTAGTGTGC-3′. PCR was performed in a 20 The Brief Assessment of Cognition in Schizophrenia (BACS) assesses the different aspects of cognition found to be important for cognitive impairment in patients with schizophrenia: (1) verbal memory measured by List Learning; (2) working memory measured by the Digit Sequencing Task; (3) motor speed measured by the Token Motor Task; (4) verbal fluency assessed using the Category Instances and Controlled Oral Word Association Test; (5) reasoning and problem solving assessed using the Tower of London; and (6) attention and processing speed assessed using Symbol Coding. The battery of tests requires approximately 30–35 minutes to complete in patients with schizophrenia and is scored by two psychologists. Further details on the BACS assessment were reported elsewhere by Keefe et al. , 21.Meta-Analysis. The references included in the analysis were searched using Pubmed (http://www.ncbi.nlm.nih.gov/pubmed), HighWire Press (http://highwire.stanford.edu), China National Knowledge Infrastructure (CNKI: http://www.cnki.net), and Google Scholar (http://scholar.google.com) without any language limitations, focusing on the keywords “schizophrenia” and “miR-137” or “microRNA-137.” The literature search was updated on May 10th, 2014. The criteria for inclusion were as follows: association studies written in English; diagnosis of schizophrenia according to standardized criteria, such as DSM or ICD-10; case-control studies investigating rs1625579 genotype and allele frequencies; available genotyping method and sufficient data to calculate the odds ratio (OR) with 95% confidence intervals (CI) and P values. The following were exclusion criteria: reviews or abstracts; studies which were not relevant to miR-137 gene rs1625579 polymorphism or schizophrenia; studies which did not report genotype frequencies. The flow of the article selection process was shown in Q test, which approximately follows a χ2 distribution with k − 1 degrees of freedom . Another statistic I2 = ((Q − (k − 1))/Q) × 100% was also used. I2 ranges from 0 to 100% [P < 0.01 and I2 > 50%.We evaluated the genetic heterogeneity among the studies included using Cochran's  to 100% . Low, mo to 100% . We defihttp://ims.cochrane.org/revman/download). If there was no significant heterogeneity among the total of six studies, including the present study , OR with corresponding 95% CI was calculated by the fixed effect model (Mantel-Haenszel); otherwise the OR was calculated by random-effect model (DerSimonian-Laird). Z test was used to determine the significance of OR.All statistical tests for heterogeneity and meta-analysis were performed using RevMan (v.5.1) software , the recessive model (TT versus GT + GG), the additive model (TT versus GG), and the allele model . In order to validate the stability of our results, sensitivity analysis for the overall effect was performed by omitting one case-control study at a time. Additionally, the publication bias was investigated with Egger's test and Begg's test using Stata 12.0 software.t-test. Generalized ORs with 95% CIs of the alleles were calculated. Descriptive variables were presented as the mean ± standard deviation (SD). P < 0.05 was considered significant for all statistical tests. The statistical analysis was performed using SPSS19.0 software, and the power calculation was performed using QUANTO 1.2 software (http://biostats.usc.edu/software).Hardy-Weinberg equilibrium was tested using Pearson's chi-squared test. Given the low frequency of the GG genotype in both schizophrenic patients (0.5%) and controls (1.0%), these cases were combined with those having the GT genotype to form the “G-allele carrier” group for all statistical tests. Statistical analyses comparing allelic and genotypic distributions were performed using Pearson's chi-squared test or Student's P > 0.05). The frequency of the TT, TG, and GG genotypes was 90.02% (n = 550), 9.66% (n = 59), and 0.33% (n = 2), respectively, in the schizophrenic patients, and 86.15% (n = 541), 13.06% (n = 82) and 0.80% (n = 5), respectively, in the controls. Because of the high prevalence of the presumed risk allele (T), we conducted the analysis according to the presence of two copies of the risk allele (TT) or only one or no copies . A significant association was observed between the case and control groups for genotype  and allele .The distribution of the miR-137 rs1625579 polymorphism in our cohort is described in Power was calculated using a G allele frequency of 0.073. Our entire cohort had a power of 0.813 for detecting a genotype relative risk with an OR of 1.5 at the 0.05 level. Therefore, our finding could be statistically strong with an appropriate sample size.χ2 = 2.275, P = 0.131 for male; χ2 = 2.240, P = 0.135 for female) or allele  distributions. Additionally, we focused on the description of relevant clinical characteristics. No significant differences were observed with regard to age, disease duration, age at onset, family history, and PANSS clinical symptom scores . There was no significant difference in the scores of the other BACS items.Neurocognitive functions were determined using BACS. The sample for neurocognitive testing consisted of 209 clinically stable patients. As shown in I2 = 0.0% for all genetic models). Associations, however, were observed between miR-137 polymorphism and schizophrenia using a dominant model , recessive model , additive model , and allele model  , recessive model , additive model , or allele model . The sensitivity analysis indicated that no single study qualitatively affected the summary risks (data not shown).In the meta-analysis derived from five published case-control studies and the present association study, no significant heterogeneity was observed in the total analysis with different models (09–1.36) . There wThe miR-137 gene was highly associated with schizophrenia in a recent GWAS analysis with an initial sample size of 21,856 and a replication sample size of 29,839 , 23, proχ2 = 4.409, P = 0.036, and χ2 = 4.971, P = 0.026, resp.). These results were replicated in a meta-analysis . The data demonstrate that the miR-137 polymorphism may affect susceptibility to schizophrenia under a recessive model for the T allele. This finding is in agreement with a GWAS [http://hapmap.ncbi.nlm.nih.gov). Therefore, genetic variation of miR-137 also exists among geographic groups within the Chinese population. However, our results and meta-analysis provide further support for the association between miR-137 polymorphism and schizophrenia even with the lower frequency of the G allele.In an attempt to replicate the GWAS findings in Asian subjects, we examined the miR-137 rs1625579 polymorphism in a Chinese Han cohort comprising 611 schizophrenic patients and 628 healthy controls. Significant differences in the genotype or allele distribution of the rs1625579 SNP were identified between schizophrenic patients and controls . In addition, overlapping microdeletion of the miR-137 locus in the chromosomal region 1p21.3 has been identified in patients with intellectual disabilities [Our study demonstrated a weak but significant association between the TT genotype and lower scores in digit sequencing for working memory in the Chinese Han population, which is similar to the results of Cummings et al. , who shobilities . Therefobilities , 30, thebilities  who founbilities . In our We failed to find an association between rs1625579 and other clinical characteristics of schizophrenia, including age onset and PANSS scores. However, recent investigations have demonstrated an association of this variant with age of psychosis onset and schizophrenia symptoms. One recent publication found that the T allele of miR-137 rs1625579 is associated with an earlier age of onset in schizophrenia . In anotAlthough the biology underlying the observed association of the miR-137 rs1625579 polymorphism remains unclear, it has been noted that the T allele of rs1625579 may be associated with a decrease in miR-137 expression in the cerebral cortex . miR-137In conclusion, the results of our case-control study and meta-analysis provide convincing evidence that the miR-137 rs1625579 polymorphism is significantly associated with schizophrenia risk. In addition, the rs1625579 polymorphism modifies working memory performance in Chinese Han patients with schizophrenia. Further investigations on the functional consequences of miR-137 polymorphism may help to elucidate the molecular mechanisms by which this genetic variant affects the schizophrenic phenotype.


NQO1, GSTM1, GSTT1, GSTP1, CYP1A1, NAT2, CYP2D6, CYP2E1, MDR1 (ABCB1), XRCC1, ARID5B, and IKZF1. The collected evidence suggests that genetic polymorphisms in CYP2E1, GSTM1, NQO1, NAT2, MDR1, and XRCC1 are capable of modulating leukaemia risk, mainly when associated with environmental exposures, such as domestic pesticides and insecticides, smoking, trihalomethanes, alcohol consumption, and x-rays. More recently, genome wide association studies identified significant associations between genetic polymorphisms in ARID5B e IKZF1 and acute lymphoblastic leukaemia, but only a few studies have replicated these results until now. In conclusion, genetic susceptibility contributes to the risk of childhood leukaemia through the effects of gene–gene and gene–environment interactions.Acute leukaemias (AL) correspond to 25–35% of all cancer cases in children. The aetiology is still sheltered, although several factors are implicated in causality of AL subtypes. Childhood acute leukaemias are associated with genetic syndromes (5%) and ionising radiation as risk factors. Somatic genomic alterations occur during fetal life and are initiating events to childhood leukaemia. Genetic susceptibility has been explored as a risk factor, since environmental exposure of the child to xenobiotics, direct or indirectly, can contribute to the accumulation of somatic mutations. Hence, a systematic review was conducted in order to understand the association between gene polymorphisms and childhood leukaemia risk. The search was performed in the electronic databases PubMed, Lilacs, and Scielo, selecting articles published between 1995 and 2013. This review included 90 case-control publications, which were classified into four groups: xenobiotic system (n = 50), DNA repair (n = 16), regulatory genes (n = 15), and genome wide association studies (GWAS) (n = 9). We observed that the most frequently investigated genes were:  Acute leukaemias (AL) are the highest incidence malignancy in children and adolescents (≤19 years of age) and as a whole, the aetiology has not yet been unveiled. There are two major groups of AL, acute lymphoblastic leukaemia (ALL) and acute myeloid leukaemia (AML), classified according to characteristics presented by leukaemic cells, such as morphological features, surface antigens, chromosomal and molecular abnormalities .Observational epidemiology has demonstrated that about 5 to 10% of AL are associated with ionising radiation exposure and congenital genetic syndromes  , that arGenetic polymorphisms are defined as natural genetic variations that occur randomly in the general population. The most common type is the single nucleotide polymorphism (SNP) that consists of a variation at a single base pair . DependiChildren are more vulnerable and susceptible to environmental toxicants than adults because of physiological immaturity, and also indirect and unintended exposures. Environmental agents such as tobacco and traffic smoke, pesticides, household chemicals, paintings, and diet are potential AL risk factors, as they may contain carcinogenic substances to humans, such as organic solvents (benzene derivatives), polycyclic aromatic hydrocarbons (PAHs), and organochloride compounds . These sThe xenobiotic system is classified into two phases: i) phase I enzymes, represented by cytochrome P450 isoenzymes (CYP), that catalyse hydrolysis, reduction, and oxidation reactions; and ii) phase II enzymes, that catalyse conjugation reactions, comprising glutathione S-transferases (GST) and N-acetyl transferases (NAT).Interindividual genetic variations that are capable of altering the process of metabolism of pro-carcinogens, in both mother and child, may modulate the risk of developing paediatric leukaemia .XRCC1, ERCC2, MLH1, MSH3. Meanwhile, double-stranded DNA breaks can be repaired by homologous recombination (HR) or nonhomologous end joining (NHEJ), throughout enzymes as nibrin (NBN) and others, encoded by several genes, such as ATM, BRCA2, and RAD51 [DNA repair systems play an essential role in maintaining integrity and genomic stability . Ionisinnd RAD51 . Failurend RAD51 . For insnd RAD51 .Cells often present signal transduction alterations that lead to proliferation in response to external factors. Several growth factors, their receptors and effector molecules have been identified as proto-oncogenes or tumour suppressor genes. Mutations in these genes may interfere with regulatory mechanisms that control cell cycle, leading to generation of malignant clones . ConsideConsidering the large amount of epidemiologic data about this subject, it becomes necessary to use systematic methods to evaluate and synthesise all the information in order to facilitate communication between molecular epidemiology and clinical practice . In an a‘acute lymphoblastic leukaemia’, ‘acute myeloid leukaemia’, ‘genetic polymorphism(s)’, ‘genetic susceptibility’, ‘xenobiotic(s)’, ‘molecular epidemiology’, ‘risk factor(s)’, and ‘child* or infant or paediatric’. Also, the following MeSH terms were used: ‘precursor cell lymphoblastic leukaemia–lymphoma’, ‘leukaemia, myeloid, acute’, ‘polymorphism, genetic’, ‘genetic predisposition to disease’, ‘gene–environment interaction’, ‘case-control studies’, and ‘genetic association studies’. References were also checked in order to look for articles that were missing in the electronic databases. The search strategy was elaborated using the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement as a guideline [A literature search on genetic susceptibility and childhood leukaemia was carried out using PubMed, Lilacs, and Scielo (last updated in June 2013). The following terms were used in different combinations: uideline .The inclusion criteria for all publications were: 1) case-control genotyping studies published between 1995 and 2013 that tested the risk of genetic polymorphisms with childhood ALL and/or AML (ages ≤ 21 years); 2) studies that provided sufficient data for estimating the risk association with odds ratio (OR), relative risk (RR) or interaction odds ratio (IOR); and 3) full text available in English, Spanish, and Portuguese. The exclusion criteria were: 1) studies with a different theme from what was proposed for this review; 2) publications in different languages, otherwise the ones specified; 3) studies that specifically include leukaemia cases related to genetic syndromes—Down, neurofibromatosis, Fanconi anaemia, Bloom syndrome and ataxia–telangiectasia—or secondary leukaemia; 4) articles that include other malignancies besides leukaemia in the same cohort, avoiding extrapolation of results exclusively for leukaemias; 5) articles about family gene transmissions; 6) articles about genes and prognosis; 7) articles about folate genes and immune system; and 8) comments and editorials.Information was extracted from each eligible article supervised by two investigators (LRA and MSPO), according to the inclusion criteria listed above. The following variables were collected from eligible studies: geographical origin, first author’s name, year of publication, leukaemia subtype, number of cases and controls, age, candidate genes investigated, and significant genotyping results.The strength of association between different genetic polymorphisms through the case-control method was evaluated by analysis of OR, RR, or IOR, with 95% confidence interval (95% CI), that were collected from the studies. Risk associations were considered significant when the P-value was ≤0.05.CYP1A1, CYP2D6, CYP2E1, CYP3A5, EPHX1, GSTM1, GSTT1, GSTP1, MPO, NAT2, NQO1, MDR1 (ABCB1), XRCC1, ERCC2, NBN, ARID5B, and IKZF1. After screening of the retrieved titles, 312 publications were identified as potentially relevant to this review . After aCYP1A1, CYP2D6, CYP2E1, CYP3A4, CYP3A5, EPHX1, GSTM1, GSTP1, GSTT1, MDR1, MPO, NAT1, NAT2, and NQO1. Most publications are from Asia (39.6%), followed by North America (25%), Europe (20.8%), and South America (14.6%). The great disparity between ethnic groups is remarkable, since the Asian continent includes a wide range of people with distinct genetic backgrounds, such as Caucasians, Turkish, Indians, Japanese, Chinese, and the Korean population, likewise, Americans have diverse ancestries, mainly Caucasian, Hispanic, and African. The vast majority of publications (75%) investigated the genetic susceptibility in ALL only, and 25% in AML + ALL; no one has investigated AML solely.Genetic susceptibility studies related to xenobiotic system are presented in CYP1A1, mainly the variant alleles *2A, *2B, *2C, and *4; only six (42.9%) found significant associations between these alleles and childhood ALL. CYP1A1*2A allele was associated with increased risk for ALL among Canadians [CYP1A1*2B was associated with increased risk for B-cell precursor ALL (Bcp-ALL) among north-Americans [CYP1A1*2C allele was also associated with increased risk for ALL among Indians [CYP1A1 variant alleles and ALL only with combined genotypes: CYP1A1*2 + CYP2E1*5B + GSTP1*B + GSTM1-null [CYP1A1*2A/*2B/*2C + NQO1 609-CT/ CT + TT [Regarding phase I metabolism, fourteen publications –32 exploanadians , Indiansanadians , and Hisanadians . CYP1A1*mericans . CYP1A1* Indians  and nort Indians . Two BraTM1-null , and CYPCYP2E1, mainly *5B, *6 and *7B; in four out of six (66.7%), significant associations were found: CYP2E1*5B was related to increased risk for ALL/AML in Canadians [*5B and *6; *6 and *7B; or *5B, *6, and *7B) was related to increased risk for ALL in Turkish [CYP2E1*5B + CYP1A1*2 + GSTP1*B + GSTM1-null was associated with increased risk for ALL in Brazilians [Six publications , 33, 34 anadians . The preazilians .CYP2D6*3 and *4 alleles. The wild-type allele (CYP2D6*1) was negatively associated with ALL in Brazilians [CYP3A genes  were investigated in four papers [CYP3A4*1B allele [CYP3A5*1 was associated with ALL increased risk in Denmark and Norway [CYP3A5*3 and CYP3A5*6 were associated with ALL protection in Brazilians [CYP3A5*6 allele only in Whites, leading to speculation that CYP3A5 may also be involved in detoxification as well as activation mechanisms of carcinogens. Alleles that do not produce a functional protein, such as CYP3A5*6, would contribute to accumulation of potentially harmful substances [Six publications –27, 35 er papers , 36, 37,B allele , 29. TheNQO1 gene (C609T and C465T). In ten studies (55.5%), divergent associations were found. NQO1 609T allele was associated with increased risk for ALL among Canadians [NQO1 609CC was associated with increased risk for ALL [NQO1 609T was negatively associated with ALL in Malaysian boys [NQO1 465T allele.Eighteen publications , 38–48 aanadians  and Brazanadians . In Fili for ALL , whereasian boys . The 609ian boys , 46, 47.ian boys , and Japian boys  with NQOEPHX1*2 (T28C–Tyr113His) and EPHX1*3 (A52G–His139Arg); two out of four showed divergent results: variant alleles *2 and *3 were associated with protection for ALL in Brazilians [*2 allele was associated with increased risk for ALL in Turkish [EPHX1 performs, its interconnection with CYP450 family, the diversity of xenobiotics presented in the environment, and the differences in allele frequencies among populations, gene polymorphisms of EPHX1 may contribute in an unpredictable way in activation or detoxification of xenobiotics.Few publications , 35, 49 MPO, mainly MPO*2 (G-463A) have a protective effect when combined to other gene polymorphisms [MPO*2 in childhood leukaemia susceptibility.Finally, three publications , 33, 35 GST gene family was the most investigated (20 case-control publications), regarding association with childhood leukaemia risk all over the world. In twelve out of seventeen [GSTM1 and GSTT1 alleles (null genotype) was related to childhood leukaemia risk: GSTM1-null genotype was associated with increased risk for ALL in ten papers [GSTT1-null genotype was associated with increased risk for ALL, mostly when combined with GSTM1-null genotype [GSTM1-null was found to be associated with protection for ALL among non-Hispanic American children [GSTM1*A, GSTM1*B and GSTT1*1 were associated with increased risk for ALL [Regarding phase II metabolism, the eventeen , 50–55 tn papers , 55; GSTgenotype , 52, 55.children , whereas for ALL . These dGSTP1 polymorphisms , only three (37.5%) showed significant associations, but with opposite results: GSTP1*B was related to increased risk for ALL among Canadians [NAT2 polymorphisms. Overall, haplotypes that result in low activity phenotype were associated with increased risk for childhood leukaemia [NAT2 341C-481T-590A, that results in slow activity phenotype, among Russians [*4 was associated with protection for ALL among Canadians [From eight publications , 56, 57 anadians , while aanadians . Seven ply three .5% showeanadians –60 analyeukaemia . The onlRussians . Besidesanadians , as wellMDR1 (ABCB1 family) gene, mainly C1236T, G2677T/A, C3435T, and T-129C, that encodes an efflux membrane transporter (P-glycoprotein) with childhood ALL. MDR1 3435T allele was consensually associated with increased risk for ALL in four publications [Besides the detoxifying function of some metabolising enzymes, membrane transporter proteins also act protectively against carcinogens. Six publications , 61–64 eications .ARNT, CYP1A2, CYP1B1, CYP2C8 and IDH1 [PON1 [NAT1 [GSTO1, and GSTO2 [AKR1C3 [Finally, few publications have explored other genes, such as and IDH1 , PON1 [3H1 [PON1 , NAT1 [5N1 [NAT1 , GSTO1, nd GSTO2 , and AKR [AKR1C3 , in chilERCC2, MLH1, MSH3, NBN, and XRCC1. Six publications (37.5%) were performed in Europeans, five (31.25%) in Asians, four (25%) in north-Americans, and one (6.25%) in Brazilians. The majority of them focused only in ALL.The data from genotyping studies in genes related to DNA repair system are summarised in XRCC1 , which encodes a protein involved in BER pathway. Seven of them (77.8%) have shown significant associations with childhood ALL. XRCC1 194Trp allele was related to increased risk among Turkish girls [XRCC1 399Gln allele was related to increased risk for ALL among Indians [XRCC1 194Arg wild-type allele and the variant alleles ERCC2 751Gln and TYMS 3R, the XRCC1 399Gln allele was related to protection for ALL among Brazilians [Nine case-control publications –75 addresh girls , Indianssh girls , and Mexsh girls , while ish girls . No publ Indians , Thai [7 Indians , Turkish Indians . Howeverazilians .ERCC2 gene encodes a DNA helicase involved in NER pathway, and its polymorphisms (Asp312Asn and Lys751Gln), were explored in five case-control publications [ERCC2 751Gln allele was related to protection for ALL among Brazilians when combined with XRCC1 399Gln-194Trp and TYMS 3R [The ications –70, 73.  TYMS 3R . The hapNBN, which is involved in DNA repair by HR, were reported by three publications [NBN gene  were associated with protection for a subset of Bcp-ALL in north-Americans [Genetic polymorphisms of ications , 76, 77.MLH1, and MSH3, were explored in two papers [MLH1 219-Ile/Ile with genetic variants of CYP2E1 or GSTM1 and CYP1A1 increased the risk for ALL [OGG1 [MUTYH [ERCC1 [XRCC4 [APEX1, BRCA2, and RAD51 [Polymorphisms of two genes involved in MMR, o papers , 78, butLL [OGG1 , 79, MUT1 [MUTYH , ERCC1 [H [ERCC1 , XRCC4 [1 [XRCC4 , 81, APEnd RAD51  found inTo date, the majority of publications regarding regulatory genes and childhood leukaemia were performed to validate GWAS results. The main investigated gene polymorphisms are summarised in CCND1 870AA genotype (homozygous wild-type) was related to increased risk for ALL among Chinese [CDKN2A (T-222A), CDKN2B  and CDKN1B (G-1608A) were also associated with childhood pre-B ALL risk among Canadians [TP53 gene was associated with increased risk for ALL among children from the United Kingdom [BAT3 and DAXX [ATM [TERT [MDM2 [LMO1 [MLL and EP300 [Prior to GWAS publications, a few genetic polymorphisms of regulatory genes were investigated by candidate gene approach.  Chinese . PolymorCDKN1B G-08A were  Kingdom . Polymorand DAXX , ATM [84TM [TERT , MDM2 [8RT [MDM2 , LMO1 [2M2 [LMO1 , MLL andIKZF1 rs4132601, rs11978267), 10q21.2 , and 14q11.2 (CEBPE rs2239633) were associated with childhood ALL risk, specifically with B-cell acute lymphoblastic leukaemia (B-ALL), and hyperdiploid subsets, with ORs ranging from 1.34 to 1.91, and P <10–7 [CDKN2A rs3731217  with protection for ALL  was validated [ARID5B rs10821936 was associated with ALL among Blacks , mainly hyperdiploid B-ALL  in the US [IKZF1 and ARID5B, and also found associations between CDKN2A rs3731217 (OR 0.8) and CEBPE rs2239633 (OR 0.9) with ALL risk [The first two GWAS regarding genetic susceptibility to childhood leukaemia were published in 2009, which observed that SNPs in regions 7p12.2 , EPB41L2 , C2orf3 , and MAN2A1  were associated with ALL risk among Koreans (P = 0.0001) [TP63 , PTPRJ , and EPOR  were associated with ETV6/RUNX1 ALL risk among Europeans [SNPs in other genes were also identified as risk variants for ALL by other GWAS, but replication of these results are still needed:  0.0001) ; TP63 , was associated with increased risk for ALL among children with father’s smoking or at least one smoker at home [CYP2C8 and MDR1 (ABCB1) were related to increased risk for ALL when associated with paint use and indoor insecticides, respectively among Hispanics living in the US [MDR1 haplotype CGC  presented a lower risk for ALL [Few publications addressed the interaction between gene polymorphisms, environmental exposures, and childhood leukaemia. Studies performed in children exposed directly and/or indirectly throughout maternal exposures are scarce. To date, environmental exposures that have been explored were smoking (tobacco exposure), pesticides, insecticides, trihalomethanes (chlorination by-products of drinking water) alcohol consumption, paint use and x-rays. The absence of  at home . Also, hn the US . Another for ALL , indicatCYP1A1*2A/*2B increased the risk for ALL by five-fold among children exposed to pesticides during maternal pregnancy and childhood, while CYP1A1*2B was related to a protective effect among children with mothers who had smoked 1–20 cigarettes during the first trimester of pregnancy  and with fathers who had smoked >20 cigarettes between birth and diagnosis  [CYP2E1*5 , and GSTT1 deletion , in pre and post-natal periods, respectively [GSTM1-null genotype and CYP2E1*5 variant were related to increased risk for ALL among children with mothers who had consumed alcoholic beverages during the third trimester of pregnancy  and nursing period , respectively [Six publications –107 esti.04–0.9) , 103. Alectively . GSTM1-nectively . Thus, iAPEX1 (Asp148Glu) and MLH1  were associated with a protective effect for ALL among girls exposed to x-rays (one or more exposures) during postnatal period  [XRCC4 GGG haplotype, consisting of SNPs rs1193695, rs301276, and rs301287, was modulated by number of postnatal x-rays (P = 0.027) [Concerning DNA repair genes, it was observed that variants of 0.0–0.7) , 107. Al= 0.027) . Again, Great scientific advances in the understanding of paediatric leukaemia have been made. Unlike the adult, who usually develops cancer because of the cumulative effect of environmental exposures during his life, the child, which manifests leukaemia with a short latency period, does not have enough exposure time to allow the initiation of a long carcinogenic process. Thus, genetic susceptibility may play an important role in modulating environmental exposures’ effects.This systematic review gathered publications up to 2013 and was an attempt to overview the risk associations between several gene polymorphisms and paediatric AL. It was possible to collect from the selected studies significant amount of data, which is considered to be a fair representation of international scientific literature on this subject. The vast majority of studies so far focused on evaluating the magnitude of risk of genetic polymorphisms in ALL, mainly because Bcp-ALL is the most frequent type of leukaemia in children. In this context, we also realised that there is still a great need for further investigations on the risk factors for paediatric AML.CYP2E1, GSTM1, NQO1, NAT2, and ABCB1 (MDR1) were more frequently associated with childhood leukaemia risk, which also showed interaction effect with environmental exposures such as paints, household pesticides, insecticides, smoking, alcohol, and trihalomethanes. Gene polymorphisms related to DNA repair have been little investigated in paediatric leukaemia, maybe because of its association with genetic diseases. However, it was noticed that XRCC1 polymorphisms play an important role in the development of ALL, and postnatal exposure to x-rays can modulate leukaemia risk in the presence of APEX1, MLH1, and XRCC4 gene variants. While interpreting these results, one has to consider that fetuses and infants are naturally more affected than adults by a variety of environmental toxicants, mainly because of differential exposure and physiologic immaturity, which makes them more susceptible to suffer from DNA damage and less capable of detoxifying carcinogenic compounds [Regarding the xenobiotic system, gene polymorphisms of ompounds . And so,Some limitations were observed in the studies that might make the consolidation of scientific evidence difficult, such as: 1) relatively small number of cases, making it difficult to obtain statistically significant results; 2) ethnic and racial differences between populations, which are reflected in distinct polymorphic allele frequencies and patterns of exposure to environmental agents; 3) little information regarding the effect of gene polymorphisms on the encoded protein; 4) and few considerations about gene–environment interactions. Also, we could observe that the majority of associations provided low risk estimates (OR <2.0), which showed that gene polymorphisms are of low penetrance, and conceptually, are minor parts of multifactorial pathways to childhood leukaemia .IKZF1 and ARID5B, which were subsequently replicated in independent studies. As a result, we see genetic susceptibility clearly contributes to childhood leukaemia risk, mainly through gene–gene and gene–environment interactions. Further studies are still needed to confirm the observed associations in different populations and to characterise environmental agents as risk factors for childhood leukaemia.More recently, GWAS have identified new gene polymorphisms potentially related to paediatric ALL, particularly involving The authors declare no conflict of interest.The study was designed by GDB, LRA, and MSPO. The literature search and data analysis were carried out by GDB, with the supervision of LRA and MSPO. The manuscript was prepared by GDB, LRA, and MSPO.


Tissue inhibitor of metalloproteinase (TIMP2) is involved in the regulation of matrix metalloproteinase 2 (MMP2) and shown to implicate in cancer development and progression. The results from the published studies based on the association between TIMP2 -418 G>C polymorphism and cancer risk are inconsistent. In this meta-analysis, we aimed to evaluate the potential association between TIMP2 -418 G>C polymorphism and cancer risk.We searched PubMed (Medline) and EMBASE web databases to cover all studies based on relationship of TIMP2 -418 G>C polymorphism and risk of cancer until October 2013. The meta-analysis was performed for selected case-control studies and pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated for all genetic models.A total of 2225 cancer cases and 2532 controls were included from ten eligible case-control studies. Results from overall pooled analysis suggested no evidence of significant risk between TIMP2 -418 G>C polymorphism and cancer risk in any of the genetic models, such as, allele , homozygous , heterozygous , dominant  and recessive  models. No evidence of publication bias was detected during the analysis.The present meta-analysis suggests that the TIMP2 -418 G>C polymorphism may not be involved in predisposing risk factor for cancer in overall population. However, future larger studies with group of populations are needed to analyze the possible correlation. Cancer is a multifactorial disease which results from complex interactions between various genetic and environmental factors Tissue inhibitor of matrix metalloproteinase  is a secretory protein, which inhibits the proteolytic activity of matrix metalloproteinase 2 (MMP2), a member of protease family principally involved in the degradation of the extracellular matrix (ECM) Considering the vital role of TIMP2 in carcinogenesis, several molecular epidemiological case-control studies have been performed to investigate the possible association between the TIMP2 -418 G>C polymorphism and cancer susceptibility in various neoplasm in different populations This meta-analysis was organized and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement . We searArticles included in the present meta-analysis had to meet all the following criteria: a) must evaluated the association between TIMP2 (-418 G>C) polymorphism and risk of cancer, b) used a case-control study design and were conducted in human beings, c) published in the English language, d) have available genotype frequency in cases and controls. Inclusion criteria for cases and controls were, a) cancer cases should confirmed histologically or pathologically, b) controls should be healthy and free of any type malignancy, c) both, the controls and the cases should have similar ethnicity. Additionally, when the same patient population was appeared in more than one publication, then only the most recent or complete study was included in this meta-analysis. The main reasons for study exclusion were, overlapping of the data, case-only studies, review articles, and genotype frequencies or numbers of the subjects were not reported. The supporting information related to the selection procedure (showing inclusion and exclusion criteria) of the studies has been appended as For each retrieved publication, the methodological quality assessment and data extraction were independently abstracted in duplicate by two independent investigators employing a standard protocol. The data-collection form was used to ensure the accuracy of the collected data by strictly adopting the inclusion criteria as mentioned above. The main characteristics abstracted from the retrieved studies included the name of the first author, year of research publication, the country of origin, the number of cases and controls, type of cancer, genotype frequencies for cases and controls and source of genotyping. Cases related with conflict or disagreement on any item of the data from the collected studies was fully debated with investigators to attain a final consensus.2 statistics was employed to efficiently test the heterogeneity http://www.meta-analysis.com/pages/comparisons.html. The Comprehensive Meta-Analysis (CMA) version 2 software program from Biostat Inc., NJ, USA was utilized for performing all statistical analysis involved in the present meta-analysis. All p-values were two sided and statistical significance level was considered as p-value less than 0.05 for this meta-analysis.In order to evaluate the strength of association between TIMP2 -418 G>C polymorphism and cancer risk, pooled ORs and their corresponding 95% CIs were calculated According to the inclusion and exclusion criteria, a total ten research articles were finally included in this meta-analysis through literature search from the PubMed (Medline) and EMBASE web databases. We excluded one article during our study selection procedure, which was published in the Chinese language Begg's funnel plot and Egger's test were carried out to review the publication bias among the selected publications for the meta-analysis. The appearance of the shape of Begg's funnel plots was seemed symmetrical in all the genetic models of this study . The Egg2 statistics were employed. Heterogeneity was observed in all the genetic models, i.e., allele (C vs. G), homozygous (CC vs. GG), heterozygous (GC vs. GG), dominant (CC+GC vs. GG) and recessive (CC vs. GG+GC). Thus, random effects model was applied to synthesize the data for this analysis , homozygous , heterozygous , dominant  and recessive  comparison models  and 2.In order to evaluate the robustness of our meta-analysis results, we performed sensitivity analysis to determine whether the inclusion criteria of this meta-analysis affected the results or not The treatment and assessment of the risk and progression of cancer remains a grave problem, as it recurs despite of its removal via surgery, and chemotherapy does not decrease cancer incidence. It has been already established that genetic factors play an important role in the etiology of cancer and several low penetrance genes are involved in the progression of cancer. Therefore, genetic marker based risk assessment might offer some benefit to better predict the risk of cancer and early detection of the disease. TIMP2 hampers the growth of endothelial cells induced by basic fibroblast growth factor, thus suppressing angiogenesis and regulating apoptosis, indicates a negative role in cancer To the best of our knowledge, this is the first meta-analysis study investigating the association between TIMP2 -418 G>C gene polymorphism and overall cancer risk. The associations for the allele contrast, dominant and recessive model were examined in the meta-analysis. The results indicated that -418 G>C polymorphism is not significantly associated with the susceptibility of cancer compared with GG genotype in overall populations. One of the possible explanations is that TIMP2 gene has several other SNPs and each polymorphism to cancer risk might be due to linkage disequilibrium (LD). It is well established that multiple SNPs perhaps act independently, collectively or interact with each other to influence the occurrence of cancer. Therefore, it is possible that multiple alleles or genes contribute the susceptibility to cancer risk and TIMP2 -418 G>C analyzed variant do not influence individually. Nevertheless, genetically complex diseases differ from simple Mendelian diseases and cancer etiology is polygenic, a single genetic variant is usually insufficient to predict the risk of this deadly disease that has a complex disease phenotype.Heterogeneity is a crucial issue while interpreting the results of any meta-analysis study. Although, heterogeneity can be minimized by performing random-effects model Despite the significant findings from our current analysis, we still have to acknowledge some of the limitations of this analysis. First, we only included studies published in English language, abstracted and indexed by the selected electronic databases were included for data analysis; it is possible that some pertinent articles published in other languages and/or indexed in some other electronic databases may have missed. Second, the result of this meta-analysis was based on unadjusted ORs because not all selected eligible studies stated adjusted ORs. Third, the role of gene-environment interactions and subgroup analysis were not considered in this study because of limited publications and insufficient data. In spite of this, our current meta-analysis has some advantage. First, there was no clear evidence of publication bias through qualitative funnel plot and quantitative Egger linear regression, which indicated that our results are statistically robust. Second, we used explicit criteria for study inclusion and performed strict data extraction and analysis to make satisfactory and reliable conclusion.In conclusion, a meta-analysis is an extremely valuable and powerful approach of data-analysis which pools both statistically significant and non-significant data from individual studies and generates a precise and absolute conclusion. The present meta-analysis evaluated the relationship of TIMP2 -418 G>C polymorphism with the risk of cancer and suggested that the TIMP2 -418 G>C polymorphism did not contribute increased or decreased risk of cancer. Further well designed large-scale studies with the consideration of gene-gene and gene-environment interactions should be encouraged to investigate the possible association. Here, we only analyzed the -418 G>C variant for cancer risk without considering the interaction between several other SNPs. In future, we will further explore the other pertinent interactions to facilitate the discovery of the pathogenesis of cancer.Figure S1(PRISMA 2009 Flow Diagram): Flow chart displaying the identification and selection of the studies for the present meta-analysis.(TIF)Click here for additional data file.Figure S2Funnel plots of the Egger's test to detect publication bias in five different genetic models. Each point represents a separate study. The OR was plotted on a logarithmic scale against the precision of the each study.(TIF)Click here for additional data file.Figure S3Sensitivity analysis of TIMP2 -418 G>C polymorphism.(TIF)Click here for additional data file.Checklist S1(PRISMA 2009 Checklist).(DOC)Click here for additional data file.


Objective. To investigate the association between bone morphogenetic protein 4 (BMP4) rs17563 polymorphism and nonsyndromic cleft lip with or without palate (NSCL/P) risk. Methods. Four online databases were researched and the related publications were collected. Odds ratio (OR) with 95% confidence interval (CI) was applied to assess the relationship; publication bias, metaregression, and sensitivity analysis were conducted to guarantee the strength of results. Results. Six published case-control studies were collected. Overall, no significant association between BMP4 rs17563 polymorphism and NSCL/P risk was found. It was notable that significant susceptibility on different ethnicity was observed in the stratified analysis. For Chinese population, the BMP4 rs17563 polymorphism was a significantly increased risk for NSCL/P . On the contrary, significantly protective effects were found in Brazilian population . Conclusion. This meta-analysis indicated that BMP4 rs17563 polymorphism could play a different role during the development of NSCL/P based on ethnicity diversity. Nonsyndromic cleft lip with or without palate (NSCL/P) is among the most common birth defects. NSCL/P occurs in approximately 1/700 to 1/1,000 live births in different areas and ethnicities worldwide .Epidemiological studies have indicated that NSCL/P development is due to the interaction between genetic and environmental factors. Genetic mutation, unhealthy habits , vitamin deficiency, and pollution increase the risk of NSCL/P. For genetic factors, approximately 20 genes are involved in the etiology of NSCL/P, including TGF-beta, MTHFR, AXIN2, IRF6, and MSX1 –6.Animal models showed that the bone morphogenetic protein 4 gene (BMP4) is among the potential candidate genes for NSCL/P . Liu et BMP4 is located at chromosome 14q22-23, contains a cDNA of 1227b with four exons, and encodes the BMP4 protein . One of In 2008, the first molecular epidemiological study was reported by Lin et al. . SignifiFour electronic databases  were searched to collect related studies. Only studies in English and Chinese were selected. The research terms included “bone morphogenetic protein 4,” “BMP4,” “nonsyndromic cleft lip with or without palate,” “cleft,” “palate,” and “polymorphism.” Furthermore, the bibliographies of some review articles were retrospectively used as complements to identify potential studies.All selected studies met the following inclusion criteria: (1) case-control or cohort design study on NSCL/P; (2) focus on BMP4 rs17563 polymorphism; (3) sufficient genotype frequency to estimate the odds ratio (OR) and 95% confidence interval (CI); and (4) being published in English or Chinese. Exclusion criteria include (1) review articles; (2) case reports; (3) preliminary results that do not include BMP4 rs17563 gene polymorphism or outcome; and (4) animal models researchers. The largest or most recently published studies were selected when similar or overlapping data are present.Data, that is, senior author's name, year of publication, sources of controls, country where the study was conducted, ethnicity of participants (such as Asian or Caucasian), genotyping method, and number of different genotypes of cases and controls, were extracted from relevant studies collected. The abovementioned data was independently completed by two reviewers (Hu and Qin). A third reviewer (Deng) examined all discrepancies in the analyses for consistency. Hardy-Weinberg equilibrium (HWE) was calculated based on the genotypes in the controls.Q statistic and I2 method. The strength of the association between the NSCL/P and BMP4 rs17563 polymorphism risk was assessed by crude ORs with 95% confidence intervals (CIs), which comprised the following models: allele contrast (C versus T); codominant (TC versus TT and CC versus TT); dominant (TC + CC versus TT); and recessive (CC versus TT + TC). If the P value < 0.10 or I2 was greater than 40%, the summary OR estimation was calculated with a random-effect model (DerSimonian and Laird method). Otherwise, the fixed-effect model (Mantel-Haenszel method) was adopted. Cumulative meta-analyses and sensitivity analysis were conducted to evaluate the stability of the results for each model. Potential publication bias was evaluated by Egger's linear regression and Begg's funnel plots. To adjust for multiple comparisons, we applied Bonferroni method with R software. Statistical analysis was performed using STATA version 11.0  and R software (version 3.1.1). All P values were two-sided. P < 0.05 was considered significant.Heterogeneity was assessed using Cochran's Thirty-three relevant studies were selected based on the search words. The flow chart of study selection is presented in P < 0.01, I2 = 0%; codominant model, CC versus TT: OR = 2.58, 95% CI = 1.74–3.82, P < 0.01, I2 = 0%; dominant model, TC + CC versus TT: OR = 1.45, 95% CI = 1.14–1.84, P < 0.01, I2 = 0%, P < 0.01, I2 = 47.0%). By contrast, significantly protective effects were found in the Brazilian population . The subsequently stratified analysis indicated that heterogeneity was absent in the Asian population  showed different susceptibilities to NSCL/P development. For the Chinese population, BMP4 rs17563 polymorphism possibly contributed to a significant increase in NSCL/P risk .Funnel plot and Egger's test were performed to estimate the publication bias of the studies. The shapes of the funnel plots in all genetic models failed to reveal any asymmetrical evidence. NSCL/P is the most common congenital malformation of the oral and maxillofacial region and is caused by a combination of genetic and environmental factors. Molecular research showed that many signaling pathways participate in the connection and fusion of the epithelium during the development of lip and palate. MTHFR, IRF6, MSX1, and TGF are proven risk factors for NSCL/P.Recently, a number of studies focused on the mechanism of BMP4 during NSCL/P development. Immunohistochemical studies show that BMP4 could be expressed in the edge epithelium at the fusion of the maxillary prominence, which forms the lateral parts of the upper lip and the secondary palate , 18. In β) superfamily. In 1999, Mangino first reported a promising candidate SNP in the human BMP4 gene, in which the amino acid valine was replaced by alanine in exon 4  [P = 0.002). The same results were also found in the overlapping and expanding data of Jianyan and colleagues [P = 0.042) [P = 0.00018). Antunes et al. [BMP4, located at chromosome 14q22-23, is a member of the BMP family and belongs to the transforming growth factor-beta TGF-l152Ala)  were thelleagues . However= 0.042) . Further= 0.042) , 13. Two2Ala  werIn our meta-analysis, the nucleotide mutation form T to C of BMP4 rs17563 will increase the risk of developing NSCL/P in Chinese population; on the contrary, the protective effects of T allele were found in Brazilian population. The different or adverse results indicated that the BMP4 rs17563 polymorphism maybe play a different role during the development of NSCL/P in different ethnicity.This meta-analysis has several limitations. First, all results were from unadjusted estimates and lacked the original data from the included studies. The relationship between gene-environment interactions and NSCL/P development was not explained. Second, because of the small sample size and the limited number of publications, the exact association between BMP4 rs17563 C mutation and NSCL/P risk was not revealed. Third, only studies on Chinese and Brazilian populations were included in our meta-analysis, thereby suggesting the presence of ethnicity bias.In summary, our meta-analysis primarily indicated that BMP4 rs17563 polymorphism may serve an important function in the development of NSCL/P based on ethnicity differences. Future case-control studies with large sample sizes are required to investigate the potential mechanism between BMP4 rs17563 polymorphism and NSCL/P.


Interleukin-23R gene polymorphism and Crohn's disease (CD) in Caucasians is still controversial. Thus, a meta-analysis was performed to evaluate the correlation between this gene variant and CD risk. We retrieved the available data from EMBASE and PUBMED until May 1, 2014, and evaluated the effect of rs7517847 in Caucasians. The significant associations were confirmed between rs7517847 and CD risk in dominant models , allelic model , homozygote comparison , heterozygote comparison , and recessive model . In conclusion, this meta-analysis demonstrates that rs7517847 is associated with the risk of CD in Caucasians. These findings show that IL-23R genes confer susceptibility to CD in the Caucasians.The association between  Crohn's disease (CD) is a form of inflammatory bowel disease (IBD) that primarily affects the Caucasian population , 2. It iβ1 and an IL-23R chain [ IL23R gene, are associated with CD occurring rate [Interleukin 23 (IL-23) plays an important role in the inflammatory response against infection as a regulator of immune cells . IL-23R 3R chain . Recentl3R chain –9. Studiing rate , 11. HowTo better understand the association of IL-23R polymorphisms and CD susceptibility in Caucasians, we conducted a meta-analysis of all eligible studies and hope to yield more accurate and robust estimates.We searched for relevant studies in the following databases: EMBASE and PUBMED. Available studies for IL-23R polymorphism and CD were collected by different combinations of various key words: Interleukin-23 receptor, IL-23R; polymorphism, variant, or mutation; Crohn's disease, CD. Languages restriction was not imposed in this research and only published studies with full text were included in this meta-analysis.In the meta-analysis, the following inclusive selection criteria were set: (a) study design evaluating the association between IL-23R polymorphism and CD risk; (b) case control design; (c) Caucasians design. The following exclusive selection criteria were set: (a) no control cases; (b) duplication of the previous publication; (c) no available genotype frequency; for studies with overlapped or repeated data (d) no Caucasians.Eligible studies were extracted by 2 reviewers (Li Zhang and Yunjie Lu) independently according to the predesigned data collection form. The following information was extracted: first author's name, publication year, country, ethnicity, immune suppressive protocol, number of cases and controls, and genotype distribution in both groups. Disagreement was resolved by discussion with a third reviewer (Guozhong Yao).Z test was performed to assess the significance of the pooled OR. Between-study heterogeneity was assessed by the Cochran's Q statistic and I2 tests [Q test exhibited a P < 0.05 or the I2 test showed >50%. Otherwise, the fixed effects model would be conducted. For publication bias, the Begg's funnel plot and Egger's linear regression test were conducted, and P < 0.05 was considered significant.For each trial, odds ratio (OR) with the 95% confidence interval (95% CI) of the survival rate was derived and calculated. Increased or decreased risk of CD was indicated by 95% CI without 1 for OR. The pooled ORs were estimated for allelic model , homozygote comparison (TT versus GG) and heterozygote comparison (TG versus GG), dominant models (TT/TG versus GG), and recessive model (TT versus TG+GG). 2 tests . The ranA fixed-effect model (based on Mantel-Haenszel method) was utilized to pool the data from different studies if the between-study heterogeneity was absent, or a random-effect model (based on DerSimonian and Laird method) was applied.P values are two-side.The statistical analysis was performed by STATA 10.0 . All The flow diagram of studies selection and exclusion reasons were represented in The OR from all models indicated a significant association between rs7517847 and CD. After pooling all the eligible studies in Begg's funnel plot and Egger's test were both performed to assess the publication bias of this meta-analysis. The shape of the funnel plots for homozygote comparison models seemed symmetrical . Then, tCD is associated with JAK2 signaling pathway which is activated by IL-23 and IL-23R receptor . PreviouOne previous study showed that rs7517847 is a protective factor in rheumatoid arthritis (RA) in European population. Interestingly, RA is a systemic autoinflammatory disease which is associated with PTPN22/C1858T, while the organ-specific autoimmune disease CD is not , 29. ThuWe should also mention the limitations of this meta-analysis. Primarily, all the studies were limited to the Caucasian. The allelic frequencies may be different in other ethnic groups. Secondly, publication bias might occur even if there is no significance in statistical test due to extracting published studies. Ultimately, owing to methodological limitations, this meta-analysis is retrospective. Two independent authors performed the process of study selection and data extraction and a third author resolved the discrepancy to minimize the bias.In conclusion, our meta-analysis suggests that IL-23R rs7517847 confers susceptibility to CD in the Caucasians. Furthermore, more studies with larger scale are required to confirm these associations.


HMGA1) gene has been previously identified as a potential novel candidate gene for susceptibility to insulin resistance and type 2 diabetes (T2D) mellitus. For this reason, several studies have been conducted in recent years examining the association of the HMGA1 gene variant rs146052672  with T2D. Because of non-univocal data and non-overlapping results among laboratories, we conducted the current meta-analysis with the aim to yield a more precise and reliable conclusion for this association. Using predetermined inclusion criteria, MEDLINE, PubMed, Web of Science, Scopus, Google Scholar and Embase were searched for all relevant available literature published until November 2014. Two of the authors independently evaluated the quality of the included studies and extracted the data. Values from the single studies were combined to determine the meta-analysis pooled estimates. Heterogeneity and publication bias were also examined. Among the articles reviewed, five studies  met the predetermined criteria for inclusion in this meta-analysis. The combined adjusted odds ratio estimates revealed that the rs146052672 variant genotype had an overall statistically significant effect on increasing the risk of development of T2D. As most of the study subjects were Caucasian, further studies are needed to establish whether the association of this variant with an increased risk of T2D is generalizable to other populations. Also, in the light of this result, it would appear to be highly desirable that further in-depth investigations should be undertaken to elucidate the biological significance of the HMGA1 rs146052672 variant.The high-mobility group A1 ( Type 2 diabetes (T2D) mellitus is a heterogeneous complex disease in which both predisposing genetic factors and precipitating environmental factors contribute to the development of the disease ,2. BecauSo far, over 50 gene variants have been associated with an increased risk of developing T2D. Whereas most of them are involved in pancreatic beta-cell function, which means in insulin secretion defects, some of them have been related to peripheral insulin resistance, which impairs peripheral glucose uptake ,7, a pheHMGA1 gene has been recently associated with increased risk of insulin resistance and T2D [HMGA1 gene encodes the nuclear architectural factor HMGA1, a non-histone basic protein that binds to AT-rich sequences of DNA via AT hooks, facilitating the assembly and stability of multicomponent enhancer complexes, the so-called ‘‘enhanceosomes”, that drive gene transcription in response to multiple extracellular and intracellular signals [HMGA1 gene [In this context, a new rare variant, rs146052672, which consists of a C insertion at position −13 of exon 6 (c.136-14_136-13insC) of the  and T2D . The HMG signals ,11. The  signals –18. Cons signals ,19,20, wGA1 gene .HMGA1 rs146052672 variant was first detected in ~8% of patients with T2D in three separate populations of white, European descent  [HMGA1 rs146052672 variant was significantly associated with T2D in a Chinese population study [HMGA1 rs146052672 variant and T2D risk, and the conclusions remain controversial rather than conclusive.The  France) . Associa France) . Later, on study , whereason study ,25. FurtHMGA1 rs146052672 variant and T2D susceptibility.Meta-analysis provides a quantitative way to combine the results of different studies on the same research question, and to estimate and explain their diversity. Therefore, conclusions from a meta-analysis are more robust than those from a single study. In addition, meta-analysis is useful to investigate the consistency or heterogeneity of the associations across studies . With thMeta-analysis was undertaken in accordance with guidelines for meta-analysis of observational studies in epidemiology (MOOSE) . ResultsHMGA1 rs146052672 variant and T2D. A comprehensive search of MEDLINE, PubMed, Web of Science, Scopus, Google Scholar and Embase databases was conducted from inception until November 2014. The following keywords in different combinations were used: “type 2 diabetes”, “high-mobility group A1 or HMGA1 or HMGI(Y)”, “variant or polymorphism” as both medical subject heading terms and text words. No language restrictions were applied in the search or study selection. Also, in order to identify additional undetected published studies, we implemented this search by carefully screening the reference list of all retrieved articles, plus the most recent review articles, and the PubMed option “Related Articles”.We sought to identify all studies that investigated the association between HMGA1 rs146052672 variant with T2D, separating results according to ethnic groups; (d) odds-ratio (OR) estimates were reported with 95% confidence intervals (CIs), or sufficient data were available to calculate these estimates; (e) method of genotyping used should have been explained or linked to a reference; (f) studies were published through November 2014. Conversely, studies would be excluded if they were case-only studies or studies of type 1 diabetes, review articles, case reports, letters, comments, editorials and duplicate publications. When the same patient population was reported in several publications, only the most recent or complete study was used. Studies published as abstracts only were excluded. Sample size or the absence of allele frequencies among cases and controls were not exclusion criteria.Two of the authors independently reviewed all potentially relevant publications to determine whether an article met the inclusion/exclusion criteria. Disagreements were discussed at a team meeting where a final decision was reached. Studies were included in the meta-analysis only if they met all the following criteria: (a) they reported original data from case-control studies performed in the adult population, regardless of the clinical/non-clinical setting where cases and controls were recruited; (b) the outcome was T2D ; (c) they investigated the association of In order to reach an assessment of the quality of each study, two of the authors independently reviewed the studies included in the meta-analysis. All eligible articles were carefully read and scored for quality, and to reduce the possibility of bias, investigators, institutions, country, and journal were blinded for each article. The Newcastle-Ottawa Scale (NOS)  was used2 test or Fisher’s exact test, where appropriate, and only in control groups. P value < 0.05 was considered significant departure from HWE. According to the quality score assessment, a study scoring < 10 was considered a “low-quality” study, whereas a score ≥ 10 represented a “high-quality” study. The lowest score was 0, and the highest score was 15 [The quality of the included publications was also evaluated according to a scale for methodological quality assessment, specifically designed for genetic studies, which was extracted and modified from previously published studies ,35. In te was 15 .The authors discussed their evaluation, and if disagreement did occur, it was solved by re-reading of the text and extensive discussion. To avoid selection bias, no study was excluded based on these quality criteria.HMGA1 gene and T2D risk; (h) type of ethnicity .Data from each included article were independently extracted by two of the authors, using a standardized data collection form. Discrepancies were resolved by discussion and, when necessary, through consultation among the investigators. We attempted to contact the authors of studies if missing data or inconsistencies were detected. The following information was recorded from each study: (a) the first author’s last name, year of publication and country of population studied; (b) study design; (c) definition of disease used in the study; (d) number of participants; (e) any confounding factors for matching or adjustment; (f) method of genotyping used; (g) OR estimates with the corresponding 95% CI for the association between the rs146052672 variant in HMGA1 rs146052672 variant compared with those without the variant. A dominant genetic model was adopted on the basis of previous observations indicating that: no statistical difference in results was observed between dominant and additive models [2 test, which gives the percentage of variation between the study estimates due to heterogeneity rather than chance. An I2 between 25 and 50% indicates low heterogeneity, between 50 and 75% moderate heterogeneity and > 75% high heterogeneity [The primary outcome was the odds of T2D in those with the e models ,25; onlye models ,22; no ce models , 22–26. e models , that cae models  was alsoogeneity ,40.HMGA1 mutations. Univariate meta-regressions were also performed to identify the major sources of between-studies variation in the results, using the previously mentioned factors as the possible sources of heterogeneity. Finally, publication bias was examined through the visual inspection of funnel plots and a scattergraph of individual studies effect against a measure of its precision [The studies included in the meta-analysis differed according to several parameters, such as study quality, ethnicity and method of genotyping. Therefore, we performed separate meta-analyses by grouping studies on the basis of quality ratings, group’s ethnicity (for Caucasians and Hispanics), and the use of TaqMan allelic discrimination confirmed by direct-sequencing as a method to detect recision , employirecision ,43. All HMGA1 gene variant rs146052672 was observed by Karnes et al. [We identified a total of 163 potentially relevant references about HMGA1 and T2D, but on obtaining and reading the articles, only five studies ,22–25 mes et al. , with res et al. ,45. Hisps et al. . All stus et al. ,22–24. FBased on the NOS, overall quality ratings of the studies ranged from 7 to 8, with a median NOS score of 7 . All stuHMGA1 rs146052672 variant on T2D. When all extracted data were pooled, 27,249 individuals were eligible for this analysis. HMGA1 rs146052672 variant on T2D risk. The combined adjusted OR estimates revealed that the rs146052672 variant genotype had an overall statistically significant effect on increasing the risk of T2D . A moderate heterogeneity was detected in the analysis . Statistical significance of the association between the HMGA1 rs146052672 variant and T2D risk was maintained also when the largest  interviewed Italian control group was included in the meta-analysis in place of the smaller (n = 784) not interviewed Italian control group  .The objective of all five selected studies was to analyze the effect of  = 0.02) . The tesHMGA1 rs146052672 variant on T2D risk, a pooled analysis was performed for potential sources of heterogeneity by combining studies that showed similar characteristics. The pooled OR estimate for all sensitivity analyses performed did not modify substantially the conclusions of the overall meta-analysis. To determine whether modification of the inclusion criteria affected the results of this meta-analysis, we initially performed sensitivity analysis excluding the study by Karnes et al. [2 = 51.3%, Q = 8.2, df = 4, P = 0.084). Meta-analysis based on high-quality studies  gave a pooled OR estimate of 1.36    and, the2 = 65.3%, Q = 8.6, df = 3, P = 0.035) , and low heterogeneity  after the exclusion of one study (22) for which genotyping was by HRM  . The tes = 0.031 . Resultss by HRM .HMGA1 rs146052672 variant’s effect on T2D. However, we cannot exclude a type II error due to the small number of studies. The I2 statistic test of homogeneity  found a high heterogeneity across the various studies, and none of the characteristics investigated appeared to modify significantly the results. Funnel plots showing ORs of the individual studies vs the reciprocal of their standard errors did not exhibit any patent asymmetry for studies exploring the effect of HMGA1 rs146052672 variant on T2D  than that seen with the TCF7L2 risk alleles (OR = 1.31–1.71) [In this meta-analysis, we evaluated the association of the rs146052672 variant in ulations ,22–25. Owww.cdc.gov/diabetes/pubs/statsreport14/national-diabetes-report%20web.pdf), more than 29 million people of the US population have diabetes. Significantly, according to the report, one in four people may not know they are diabetics. The report also indicates that 86 million Americans aged 20 years or older have prediabetes, a condition where blood glucose is higher than normal but not high enough to be diagnosed as T2D [The choice of choosing a suitable control group is of considerable significance and one of the most difficult aspects of case-control design , in whicd as T2D –52. Accod as T2D . Thus, td as T2D , includid as T2D –57. Consd as T2D , than inHMGA1 gene mutations, and ethnicity. Although we were not able to completely rule out heterogeneity in the sensitivity analysis, this analysis allowed us to elucidate the extent to which each of the covariates investigated contributed to the overall heterogeneity, and, indeed, heterogeneity was eliminated when the method used for genotyping was involved. We are conscious that heterogeneity among ethnic groups may have impact on the results, and this is especially critical considering the disparate frequencies of the mutation among ethnic groups. However, subgroups analysis may be provided only for Caucasians and for Hispanics, as data on Asians and Africans were each from a single study. Although we were not able to reduce heterogeneity in the sensitivity analysis by ethnic groups, due to the small number of studies, we cannot exclude to have failed to find a difference. More studies in different ethnic groups are needed.A word of caution to the interpretation of our data is appropriate in view of the heterogeneity we found in our analysis. To address this point, we conducted sensitivity analysis and meta-regression according to characteristics retrieved from the single studies and that could have affected the overall results, such as control population recruitment, TaqMan allelic discrimination confirmed by direct sequencing as a method to analyze HMGA1 rs146052672 variant and the risk of T2D, we perceive this as an ulterior strength of this work that should trigger further research in this direction. Conversely, as limitations of this study, we should mention that the association between HMGA1 rs146052672 variant and T2D is not widely studied and, therefore, the number of analyzed articles was small, thus introducing a problem of inadequate statistical power, as frequently occurs in studies evaluating the role of genetic polymorphism. Nevertheless, when all extracted data were pooled, a sizeable number of subjects were eligible for analysis. Also, as this meta-analysis was based on data from case-control studies that are susceptible to selection bias, failure to consider potential confounders cannot be ruled out.A particular strength of the present work lies in the rigorous methods used to select studies and evaluation of potential risk of bias. We did not find any evidence of publication bias in the studies reviewed here, which decreases the likelihood that our findings were due to our method of article selection. Furthermore, as this is the first meta-analysis to report an association between HMGA1 rs146052672 variant and T2D risk. However, although an impact of the HMGA1 rs146052672 variant on risk of T2D is supported in this meta-analysis, biological evidence for this association is still lacking; while reductions in both HMGA1 mRNA and protein expression were reported in both blood monocytes and transformed lymphoblasts obtained from diabetic patients carrying the rs146052672 variant [HMGA1 mRNA expression only in subcutaneous fat of healthy Scandinavian subjects with the variant [In accordance with the interim guidelines for epidemiologic credibility in the assessment of cumulative evidence on genetic associations , our met variant , this fi variant , and by  variant . Though  variant ,60, therHMGA1 gene might increase the risk of development of T2D. Given that the number of available published studies focusing on this issue was limited and most of the study subjects were Caucasian, further investigation is needed to see whether these findings can be generalized to other populations.This meta-analysis provides supporting evidence that the rs146052672 variant in the S1 Supporting Information(DOCX)Click here for additional data file.S2 Supporting Information(DOCX)Click here for additional data file.S3 Supporting Information(DOC)Click here for additional data file.


Background. Controversy remains for the association between hepatocyte nuclear factor 4α (HNF-4α) P2 promoter polymorphism rs1884613 and type 2 diabetes (T2D). There was no association test of this polymorphism with prediabetes and T2D in the Chinese population. Moreover, an updated meta-analysis in various ethnic groups is needed to establish the contribution of rs1884613 to T2D risk. Methods. Using the Sequenom MassARRAY platform approach, we genotyped rs1884613 of HNF-4α in the P2 promoter region among 490 T2D patients, 471 individuals with prediabetes, and 575 healthy controls. All the individuals were recruited from 16 community health service centers in Nanshan district in Shenzhen province. Using STATA 11.0 software, meta-analysis was performed to summarize the overall contribution of rs1884613 to T2D risk. Results. Polymorphism rs1884613 was associated with genetic susceptibility to prediabetes in the whole samples  and the female subgrouped samples  after adjusting for age and body mass index (BMI). In contrast, there was no association of rs1884613 with T2D in the whole samples and male in our case-control study and meta-analysis. Conclusions. Our results suggest that rs1884613 contributes to susceptibility to prediabetes, whereas this polymorphism may not play an important role in the development of T2D. The prevalence rate of type 2 diabetes (T2D) is increasing rapidly, with 8.4% of the global prevalence rate of the adults according to the International Diabetes Federation . T2D is β-cells, hepatocyte nuclear factor 4α (HNF-4α) is differentially expressed in many tissues including the liver and pancreas [ HNF-4α spans 29 kb on chromosome 20q13.1-13.2 [ HNF-4α was shown to play a significant role in the development of maturity-onset diabetes of the young-1, which is characterized by impaired insulin secretion [As a pivotal transcription factor in the progress and functions of the pancreatic pancreas . HNF-4α 3.1-13.2 , which iecretion . HNF-4α P2 promoter, which is about 45.6 kb upstream of the transcription start site and regulates the primary splicing form of HNF-4α in the pancreatic β-cell [Polymorphism rs1884613 is located in thec β-cell . Strong c β-cell . HNF-4α was tested with T2D susceptibility in various ethnicities but not in the Chinese Han population. Considering the diverse genetic background among different populations, for which they may have a different predisposing genetic risk, the influence of rs1884613 on T2D susceptibility in the Chinese population remained to be identified. Therefore we studied the association of rs1884613 among 490 T2D subjects, 471 prediabetes subjects, and 575 healthy controls to extend knowledge in different populations.P2 promoter polymorphism rs1884613 ofWinckler et al. demonstrated the significant association of rs1884613 in the P2 promoter region in >3,400 patients and controls from Sweden, Finland, and Canada; however they did not confirm the significant association in an additional sample of 4,470 patients from North America and Poland (trended in the opposite direction) . The inc2), 471 were prediabetes subjects , and 575 were healthy controls .The participants in the current study came from 16 community health service centers (CHSC) in Nanshan district under the supervision of Shenzhen Nanshan Center for Chronic Disease Control. We applied a two-stage sampling method and a simple random procedure according to the sequence of computer-generated random numbers. Among those 1516 subjects, 490 had T2D : 24.95 ± 3.46 kg/mT2D and prediabetes were diagnosed according to the criteria of the American Diabetes Association guidelines in 2010 . InformeThe blood samples (5 mL) were collected after overnight fasting at morning without stasis in EDTA vacutainers. Polymorphism rs1884613 was genotyped using Sequenom's MassARRAY iPLEX system according to the manufacturers' instructions. Primers for the PCR and single base extension were designed using the Sequenom software. DNA sequences of primers were 5′-ACGTTGGATGACTCTGTCGTGGCTCCAGTA-3′ and 5′-ACGTTGGATGAATTGGCTTGTGGACATCCG-3′. Thermocycling was carried out under the following conditions: 94°C for 15 min followed by 45 cycles at 94°C for 20 s, 56°C for 30 s, and 72°C for 1 min, with a final incubation at 72°C for 3 min.χ2 test. To prevent the influence from genetic assumptions on the inheritance models, additive, recessive, and dominant models were applied for the association tests. Binary logistic regression analysis was used to calculate the odds ratios (ORs) and 95% confidence intervals (CIs) after being adjusted by age and BMI. Bonferroni's adjustment was applied to the significance thresholds, and a P value of <0.008 was adopted as the significant threshold  was assessed by hreshold . Power aHNF-4α” or “polymorphism” or “variant” or “rs1884613” and in combination with “diabetes” or “T2D.” The reference lists in the involved articles were also checked for additional relevant publications. Two investigators independently extracted the following data: the first author's name, year of publication, country, ethnicity, source of controls, number of cases and controls, the available genotype, and allele frequencies. Any disagreement was resolved by discussion. ORs with 95% CIs were estimated to assess the strength of association; the significance was determined using the Z test . Subgroup analyses were performed based on ethnicity (Caucasian or Asian) and source of control groups . Heterogeneity was measured using Cochran's Q test and I2 test [P > 0.10), the fixed-effect model was used to evaluate the summary ORs and 95% CIs. Otherwise, the random-effect model was applied. The I2 was used to estimate the heterogeneity quantitatively, with I2 < 25%, 25–75%, and >75% represented as low, moderate, and high degrees of inconsistency, respectively. Meta-analysis was conducted with the STATA software .Eligible studies were identified by searching PubMed, Embase, Cochrane Library, and Science Citation Index Expanded databases for articles published in English until July 10, 2014. We applied the following search terms: “P values presented were corrected for multiple testing (with P < 0.008 as significant threshold). According to power calculations, our sample size provided > 90% power (at ∂ = 0.05) to detect the relative associations for rs1884613 with prediabetes risk.The characteristics of the case-control subjects were shown in P = 0.0001) and in female samples (P = 0.003). However, no association was found for the relationship between rs1884613 and T2D in the whole and male samples under the Bonferroni's correction . No significant associations were observed in the stratified analyses by source of controls and ethnicity  with T2D in Scandinavians and Caucasian Americans [Consistent with our study, Winckler et al. and Bagwell et al. reported no association ofmericans , 18, altmericans , the Ashmericans , the Mexmericans , and themericans . The oppmericans , 16. It mericans , 0.18 inmericans , 0.27 inmericans , and 0.4There may be some unknown susceptibility functional variants that are in linkage disequilibrium (LD) with rs1884613 in the populations with positive findings. The conflicting results in other studies may be due to the varying LD patterns in different tested populations. Polymorphisms rs4810424, rs1884613, rs1884614, and rs2144908 were in almost complete LD in the Finnish and Ashkenazi Jewish populations; however the four polymorphisms are not situated in any confirmed functional regions , suggestHNF-4α T130I polymorphism is a rare nonsynonymous variant that was shown to regulate HNF-4α gene expression and thus was shown to be associated with T2D risk [ PPARG Pro12Ala and HNF-4α rs2144908 was shown to postchallenge insulin secretion [ HNF-4α [ HNF-4α variants to T2D risk is not alone.T2D risk , 24. Furecretion . Trip3 g[ HNF-4α . The aboP = 0.0004) [In order to confirm the association between rs1884613 and T2D susceptibility, we performed a meta-analysis among 8569 cases and 8528 controls from 8 studies including ours. Our meta-analysis showed there was no significant association between rs1884613 and T2D risk. Compared with the previous two meta-analyses , 17, the 0.0004) . HNF-4α with T2D and prediabetes should be further evaluated in future studies with different populations. Secondly, some populations in our meta-analysis consisted of the T2D cases from families with history of T2D. This may have confounded the results of the current meta-analysis. Thirdly, due to a lack of the detailed genotype frequency in most studies, the current meta-analysis only adopted the additive model that may not be the best heritable mode for this polymorphism. Fourthly, only a few studies had prediabetes subjects; therefore we were not able to perform the meta-analysis between rs1884613 and prediabetes risk. Last but not least, large heterogeneity was observed in the population-based subgroup meta-analysis. Since the hospital-based studies usually tend to have higher heterogeneity, the high heterogeneity in population-based studies may be due to the fact that some of the patients came from the families with history of T2D.There are some limitations to be noted. Firstly, we only genotyped rs1884613 under the hypothesis that rs1884613 may be in LD with other P2 promoter variants. It may not stand for the whole P2 promoter variants in the Han Chinese population, although previous findings have shown the P2 promoter variants are in high LD with each other in Europeans ; therefo HNF-4α is associated with prediabetes in Han Chinese population, whereas this polymorphism may not play an important role in the risk of T2D according to our case-control study and the updated meta-analysis. Future study is warranted to explore the LD patterns in the P2 region among the T2D patients from different ethnic populations.In conclusion, our results suggest that rs1884613 of