Kim JJ, Hwang KR, Shin S, Yoon JH, Kim BJ, Choi YM, Roh EY. Association of polycystic ovarian syndrome with human leukocyte antigen polymorphism in Korean women. APMIS 2011.Although several studies have demonstrated the genetic contribution to polycystic ovarian syndrome (PCOS), the cause of this syndrome remains unclear. The aim of this study was to elucidate the relationship between human leukocyte antigen (HLA) systems and PCOS in Koreans. We compared the HLA‐A, B and DRB1 genotype distribution of 52 PCOS patients and 67 healthy Korean women. In addition, we investigated the association of HLA with free‐testosterone level. HLA‐A*11, A*31 and B*54 showed increased phenotype frequencies (PFs) in PCOS women compared to controls (p = 0.032, OR 2.79; p = 0.019, OR 6.05; p = 0.002, OR 6.40). HLA‐DRB1*15 showed negative correlations with the free‐testosterone concentration both in total subjects and PCOS patients (p = 0.024 and p = 0.008). The results of the study suggest mild associations of HLA alleles with pathophysiology of PCOS and/or testosterone production in PCOS. Further investigation in a large number of subjects, including subdivision and multi‐population studies, will need to be conducted to prove the consistent or variable association in PCOS.