Association of rs10830963 and rs10830962 SNPs in the melatonin receptor (MTNR1B) gene among Han Chinese women with polycystic ovary syndrome

The aim of the present study was to determine whether or not the 'melatonin receptor (MTNR1B)' gene polymorphisms are associated with a predisposition for polycystic ovary syndrome (PCOS). The single-nucleotide polymorphisms (SNPs), rs10830963 and rs10830962, in the MTNR1B gene were detected in 526 patients with PCOS and 547 healthy Chinese Han women. The association between MTNR1B gene variants and plasma glucose and insulin levels during the oral glucose tolerance test (OGTT) and hormone levels was investigated. The frequencies of three genotypes and two allelotypes of the SNP, rs10830963, differed significantly between women with PCOS and healthy controls (P < 0.001 and P < 0.001, respectively). The SNP, rs10830963, was significantly associated with higher fasting plasma glucose concentrations (P < 0.001) and increased the area under the curve of plasma glucose levels during the OGTT (P < 0.001), as well as increased homeostasis model assessment of insulin resistance (HOMA-IR; P = 0.027). No significant differences were observed in the genotypes and allele distributions of rs10830962 polymorphisms between the PCOS and the control groups (P = 0.311 and P = 0.178, respectively). There was no significant difference in the clinical and the metabolic characteristics in women with PCOS with different genotypes in the SNP, rs10830962 (all P > 0.005). The present study suggest that the SNP, rs10830963, in the MTNR1B gene is not only associated with susceptibility to PCOS, but also contributes to the PCOS phenotype.