In-silico analysis of non-synonymous SNPs in insulin binding site of insulin receptor and screening in Indian PCOS women

Insulin resistance (IR) is one of the major patho-physiology of polycystic ovary syndrome (PCOS) among women of reproductive age. Generally, PCOS women with IR incur metabolic syndrome consisting of high blood glucose, cholesterol, and insulin levels due to mutations in the insulin receptor gene. Our study aimed at identifying putative deleterious nsSNPs on the insulin binding site of the INSR gene using in silico tools and screening these SNPs in the Indian PCOS women diagnosed with metabolic syndrome. The INSR gene with a total of 7142 SNPs were retrieved from dbSNP, with six non-synonymous SNPs found at the insulin-binding site. Three out of six nsSNPs (i.e. rs1294314902, rs1568448566, rs1353116498) were pathogenic as predicted using SIFT, PROVEAN, PolyPhen2, SNAP2 tools, whilst the stability and structural changes were validated using Project HOPE, MutPred2, and MuPro tools. Further, structural modelling, docking, and simulation were employed, which resulted in a wide difference between the docking scores of insulin ligand binding with wild-type and mutant proteins, indicating potential deleteriousness of the nsSNPs and their functional and structural implications. Further, SNPs were examined by utilizing Sanger sequencing using the primers specific to the insulin binding site of the INSR gene in sixty-three PCOS women diagnosed with high blood glucose and insulin resistance. However, none of these nsSNPs were found in the cohorts.