Human Genome Epidemiology (HuGE) Review Meta-Analysis of Vitamin D Receptor Polymorphisms and Type 1 Diabetes: A HuGE Review of Genetic Association Studies

Several polymorphisms in the vitamin D receptor (VDR) gene have been reported to be associated with the risk of developing type 1 diabetes, yet published findings have been conflicting. In this study, the authors attempted to evaluate the evidence regarding the association. They searched all relevant reports from original papers published from 1997 to December 2005. Predefined criteria were used to identify 1) case-control association studies exam-ining the Fok I (11 studies), Bsm I (13 studies), Apa I (9 studies), and Taq I (7 studies) polymorphisms and 2) a few family-transmission studies with analysis of these four polymorphisms. In random-effects modeling, the 95% confidence intervals of the summary odds ratios for all four polymorphisms included 1, indicating no effect. Except for Fok I, no heterogeneity was found. The 95 % confidence intervals of the transmission proportions all included 0.5, indicating no effect. Thus, the authors found no evidence for an association between VDR gene polymor-phisms and type 1 diabetes risk in either case-control studies or family-transmission studies. In fact, a reanalysis of previously published data (McDermott et al., Diabetologia 1997;40:971–5) indicated no evidence of an association as reported. association; diabetes mellitus, type 1; epidemiology; genetics; meta-analysis; polymorphism, genetic; receptors, calcitriol;VDR Abbreviations: CI, confidence interval; SNP, single nucleotide polymorphism; VDR, vitamin D receptor. Editor’s note: This article is also available on th