Arylamine N-acetyltransferase 1 (NAT1) genotypes in a Lebanese population.

The frequency distributions of human N-acetyltransferase 1 (NAT1*) alleles in various ethnic groups are largely unknown. This lack of information is in contrast to the many studies of ethnic differences in NAT2* alleles and phenotypes. Increasing interest in NAT1 due to its potential roles in carcinogen metabolism and cancer risk makes it desirable to know the distribution of NAT1* alleles in various populations. Using a polymerase chain reaction-restriction fragment length polymorphism genotyping assay, the frequency of NAT1* alleles in a Lebanese population was determined. Of 84 NAT1* alleles assayed, 56% were NAT1*4. Alleles NAT1*3, *10, and *14 were found at frequencies of 0.036, 0.107, and 0.238, respectively. Five additional alleles (6%) differed from previously reported alleles. Nearly 50% of the population were heterozygous for a NAT1*14 allele. The unusually high frequency of NAT1*14 alleles in Lebanese may be useful for epidemiological studies of the effects of the NAT1 polymorphism in this population.