Twenty-five subjects (23.8 %; CI: 15.7-32.0 %) had PCOS with higher prevalence of OHSS (40 % vs. 7.6 %; p < 0.001), younger age [30.5(0.7) vs. 33.3 (0.5); p = 0.005] and higher basal AMH levels [7.1(0.7) vs. 3.3(0.3); p < 0.001]. The gene discussed is AMH; the disease is polycystic ovary syndrome.