Polymorphisms in insulin receptor substrate-1 gene are not associated with gestational diabetes

OBJECTIVE: Previous investigators have shown an association belueen polymorphisms at nucleotides nlS and 972 of the insulin receptor substratr-1 (IRS-1) and non-insulin-dependent diabetes mellitus. Our objective was to determine the frequency of these two polymorphisms in a population with gestationa! diabetes mellitus (GDM). STUDY DESIGN: UNA was extracted from whole blood of "18 patients with gestational diabetes mellitus. diagnosed bv 2 abnormal values on a 3 hour oral glucose tolerance lest, and 71 gravid women without a diagnosis of gestational diabetes. Polvmerase chain reaction (PC'R) was used to amplify codons 513 and 972. Allele-speciiic restriction was used for the polymorphism anaKsis. βs/A7 for 972A and DRAIII for 513C. RESULTS: IRS-1 Allele Frequencies V72 72A 13C, 513C GDM n = 58 94f/f (>% 98% 2% Ciontrols n = 89% 11% 98% 2% Published Controls n = 147 98% 2% 99% 1% CONCLUSIONS: We did not find an association between these polymorphisms in IRS-1 and GDM. Furthermore, the allele frequency diffeience between our population and published controls from Denmark suggest ethnic variation in this gene which ma\ confound association studies.