The genetic susceptibility profile of the South Indian women with polycystic ovary syndrome and the universality of the lack of association of type 2 diabetes genes

Abstract

We explored genetic susceptibility profile of the South Indian women with a large set of SNPs and tested if the lack of association of type 2 diabetes genes with PCOS, recently observed in a number of studies, holds true for this Indian population and suggest probable universality of this phenomenon. A prioritized set of 92 SNPs that belong to important reproductive and metabolic pathway genes were genotyped on 250 PCOS cases and 299 ethnically matched controls, representing the southern Indian population of Hyderabad, using SEQUENOM MassARRAY iPLEX™ platform. These data were analyzed both for individual SNP association patterns as well as for gene-gene interactions, besides obtaining cumulative risk score and the ROC curve with the help of appropriate statistical packages such as PLINK, SNPAssoc of R-program, Haploview, GMDR and SPSS. The analysis of 72 of the 92 SNPs, after excluding 20 of those that showed either minor allele frequency < 1% and/or deviated from Hardy Weinberg Equilibrium (p < .001), suggested that only 13 were associated with PCOS at p ≤ .05, but none after correction for multiple testing. Further, neither any of the diabetic genes nor the interactions between diabetic and reproductive pathway genes were found to be significant even at p ≤ .05.The lack of association of any of the SNPs with PCOS and/or the gene-gene interactions among them may be because of the minor effects of each of them on the phenotype(OR < 2). Further, that none of the type 2 diabetes genes were associated with PCOS in the present study as well as in the earlier studies from different ethnic groups may indicate probable universality of this pattern. It is possible that there are still other genetic variants, novel as well as already known, which may confer greater risk than the ones considered in this study and further studies are warranted to ascertain this both in the present population as well as in other ethnic and/or geographic groups of the Indian subcontinent.