title: Meta-analysis of the relationship between common type 2 diabetes risk gene variants with gestational diabetes mellitus.
abstract: BACKGROUND
  A number of case-control studies were conducted to investigate the association of common type 2 diabetes (T2D) risk gene polymorphisms with gestational diabetes mellitus (GDM). However, these studies have yielded contradictory results. We therefore performed a meta-analysis to derive a more precise estimation of the association between these polymorphisms and GDM, hence achieve a better understanding to the relationship between T2D and GDM.
  
  
  METHODS
  PubMed, EMBASE, ISI web of science and the Chinese National Knowledge Infrastructure databases were systematically searched to identify relevant studies. Data were abstracted independently by two reviewers. A meta-analysis was performed to examine the association between 9 polymorphisms from 8 genes and susceptibility to GDM. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated. Heterogeneity among articles and their publication bias were also tested.
  
  
  RESULTS
  We identified 22 eligible studies including a total of 10,336 GDM cases and 17,445 controls. We found 8 genetic polymorphisms were significantly associated with GDM in a random-effects meta-analysis. These polymorphisms were in or near the following genes: TCF7L2 (rs7903146), MTNR1B (rs10830963), IGF2BP2 (rs4402960), KCNJ11 (rs5219), CDKAL1 (rs7754840), KCNQ1 (rs2237892 and rs2237895) and GCK (rs4607517); while no association was found for PPARG with GDM risk. Similar results were also observed under dominant genetic model for these polymorphisms.
  
  
  CONCLUSIONS
  This meta-analysis found 8 genetic variants associated with GDM. The relative contribution and relevance of the identified genes in the pathogenesis of GDM should be the focus of future studies.
authors.affiliation: Department of Gynecology and Obstetrics, Qidong People's Hospital, Jiangsu, People's Republic of China.
authors.forename: Hongyan
authors.initials: H
authors.lastname: Mao
authors.forename: Qin
authors.initials: Q
authors.lastname: Li
authors.forename: Shujun
authors.initials: S
authors.lastname: Gao
mesh_terms: D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000235:genetics*; D016640:Diabetes, Gestational / Q000235:genetics*; D005260:Female; D005796:Genes; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D006801:Humans; D020641:Polymorphism, Single Nucleotide; D011247:Pregnancy; D012306:Risk