Although the frequency of the CT genotype of MTHFR C677T polymorphism was not statistically varied among PCOS and control females before and after adjusting age and ethnicity, the frequency of TT genotype was notably greater in PCOS women contrasted to controls before and after setting lifetime and ethnicity and risk of PCOS was 1.7 fold greater in women with TT genotype after setting lifetime and ethnicity [OR, 1.7 (95% CI 1.1 to 2.7); P = 0.02]. The gene discussed is MTHFR; the disease is polycystic ovary syndrome.