FTO and polycystic ovary syndrome: In subgroup analysis stratified by ethnicity, significant association between FTO 9939609 A/T and PCOS risk was observed in Caucasian and Asian populations under dominant model (OR = 1.33, 95% CI = 1.08–1.64, P = 0.008; OR = 1.43, 95%CI = 1.29–1.59, P < 0.00001, respectively).