N-Acetyltransferase genetics and their role in predisposition to aromatic and heterocyclic amine-induced carcinogenesis.

N-Acetyltransferases (EC 2.3.1.5) are important in both the activation and deactivation of aromatic and heterocyclic amine carcinogens. Two N-acetyltransferase isozymes (NAT1 and NAT2) encoded by NAT1 and NAT2, respectively, have been identified. Both NAT1 and NAT2 exhibit genetic polymorphisms, and recent investigations have increased our understanding of the relationship between genotype and phenotype. Several studies have shown a role for NAT1 and NAT2 acetylation polymorphisms in cancer risk in human populations, but the findings have been inconsistent. These findings may relate to variability in carcinogen exposures and to differences in acetylator genotype/phenotype determinations.