Phenotypic Expression of Polycystic Ovary Syndrome in South Asian Women

Polycystic ovary syndrome (PCOS) occurs in 6% to 10% of women and, as the most common worldwide endocrinopathy of reproductive-aged women, is linked to a constellation of reproductive and metabolic abnormalities, including anovulatory infertility, hirsutism, acne, and insulin resistance in association with metabolic syndrome. Despite a genetic component to PCOS, ethnicity plays an important role in the phenotypic expression of PCOS, with South Asian PCOS women having more severe reproductive and metabolic symptoms than other ethnic groups. South Asians with PCOS seek medical care at an earlier age for reproductive abnormalities; have a higher degree of hirsutism, infertility, and acne; and experience lower live birth rates following in vitro fertilization than do whites with PCOS. Similarly, South Asians with PCOS have a higher prevalence of insulin resistance and metabolic syndrome than do other PCOS-related ethnic groups of a similar body mass index. Inheritance of PCOS appears to have a complex genetic basis, including genetic differences based on ethnicity, which interact with lifestyle and other environmental factors to affect PCOS phenotypic expression.