Lack of association between endometriosis and N-acetyl transferase 1 (NAT1) and 2 (NAT2) polymorphisms in a Japanese population.

OBJECTIVE: We investigated the association between endometriosis and polymorphisms in the N-acetyltransferase 1 (NAT1) and N-acetyltransferase 2 (NAT2) genes in a Japanese population, having previously demonstrated a positive association with NAT2 polymorphisms in a UK population. METHODS: Genotyping for NAT1 alleles *3, *4, *10, and *11, and NAT2 alleles *4, *5A, *5B, *5C, *6A, and *7B was performed using polymerase chain reaction-restriction fragment-length polymorphism (PCR-RFLP) and allele-specific PCR (AS-PCR) analysis in 145 ethnically Japanese, endometriosis patients and 182 controls. The NAT1 and NAT2 allele and genotype frequencies were compared in cases and controls using the Fisher exact test. RESULTS: No significant differences between cases and controls were observed in the frequencies of the NAT1 and NAT2 alleles (P = .13; P = .91) and genotypes (P = .24; P = .79), and the NAT2 acetylation phenotypes (P = .46). Dividing the cases into a subgroup, consisting of women with severe disease only (n = 80), had no effect on the results. CONCLUSION: The distribution of NAT1 and NAT2 allele and genotype frequencies were not significantly different between Japanese cases and controls. Our findings suggest that polymorphisms in NAT1 and NAT2 are unlikely to be associated with an increased risk of endometriosis in the Japanese population.