Catechol-O-methyltransferase gene polymorphism in women with polycystic ovary syndrome

Abstract

OBJECTIVE: Polycystic ovary syndrome (PCOS) is the most common cause of anovulation in women of reproductive age. One of the characteristic features of PCOS is the arrest of follicular maturation. Catechol-O-methyltransferase (COMT) is the principal enzyme in conjugation and inactivation of the catechol estrogens. Overexpression of COMT, which is prevalent in PCOS, increases the level of 2-methoxyestradiol in granulosa cells and leads to ovulatory dysfunction. The COMT gene G→A single nucleotide polymorphism at codon 158 results in substitution of methionine to valine, which is associated with 3-4 folds decreased enzyme activity. We attempted to evaluate the association between COMT gene polymorphism and PCOS. DESIGN: Case control study. MATERIALS AND METHODS: The COMT genotypes were determined in 156 PCOS patients and 116 controls by PCR-RFLP method. To evaluate the effect of the COMT genotype on the phenotype, PCOS patients were classified into four groups as follows: 1) irregular menstruation (IM), hyperandrogenism (HA) and polycystic ovary (PCO), 2) IM and PCO, 3) IM and HA and 4) HA and PCO. Chi square test was conducted as appropriate and a p value of <.05 was considered as statistically significant. RESULTS: The COMT genotype distributions in both PCOS patients and the controls were in the Hardy-Weinberg equilibrium. Genotype distribution of the COMT gene was not different between PCOS patients and the controls (G/G of 50.6% vs. 52.2%, G/A of 41.0% vs. 38.2%, and A/A of 8.3% vs. 11.2%, respectively). There was also no difference in the G and A allele frequencies between the two groups (71.2% vs. 71.6%, and 28.8% vs. 28.4%, respectively). The COMT genotype distribution of the each subgroup of PCOS patients was not statistically different from that of the controls (p values were .89 for group 1), .14 for group 2), .21 for group 3) and .81 for group 4)).Table 1Distribution of COMT gene polymorphismGroupSNP rs898611 genotypeAllele frequencyAAAGGGpAGpPCOS (n=156)13 (8.3%)64 (41.0%)79 (50.6%).474 ∗90 (28.8%)222 (71.2%).919 ∗Control (n=116)13 (11.2%)40 (38.2%)63 (52.2%)66 (28.4%)166 (71.6%)∗ χ2-test in comparison with the control group. Open table in a new tab ∗ χ2-test in comparison with the control group. CONCLUSIONS: These results suggest that codon 158 G/A polymorphism of the COMT gene is not associated with the risk of PCOS in the Korean population. Phenotype of PCOS was also not affected by the COMT genotype.