Catechol-O-methyltransferase (COMT) single nucleotide polymorphisms and haplotypes are not major risk factors for polycystic ovary syndrome

► Catechol-O-methyltransferase gene (COMT) variants are not significantly associated with polycystic ovary syndrome. ► No significant correlations between COMT genotypes and total testosterone, non-SHBG bound testosterone and BMI were found. ► COMT haplotypes associated with reduced enzyme activity were associated with higher prolactin levels in PCOS women. ► COMT haplotypes associated with higher enzyme activity were associated with lower prolactin levels. ► Significant associations between COMT haplotypes and prolactin may reflect a role of COMT variation in the stress response.