Arylamine N-acetyltransferase 2 slow acetylator polymorphisms in unrelated Iranian individuals.

Objective: To determine the frequency of mutations at the polymorphic gene coding for arylamine N-acetyltransferase 2 (NAT2, EC 2.3.1.5) and NAT2 genotypes associated with slow acetylation in healthy Iranian individuals.

Methods: The polymorphisms in the NAT2 gene from 88 unrelated healthy subjects (48 men/40 women) from the general Tehran population were discriminated using polymerase chain reaction (PCR) with allele-specific primers (341 C > T) and PCR-restriction fragment length polymorphism analysis (481 C > T, 590 G > A, and 857 G > A).

Results: Frequencies of the studied polymorphisms showed the most common alleles to be NAT2*4 (0.43) and NAT2*5, 481 C > T (0.32), followed by NAT2*6 (0.19) and NAT2*7 (0.06), previously referred to as WT, M1, M2, and M3, respectively. The most prevalent genotypes were NAT2*4/*5 [(31.8%; 95% confidence interval (CI): 29-34%] and *4/*4 (18.2%; 95% CI: 16-21%). When grouped according to the expected phenotypical effects, the resulting genotypes revealed the significant prevalence of the subjects with slow (32.9%) and intermediate (48.9%) acetylation status compared with wild-type rapid (18.2%) acetylators (P < 0.01).

Conclusions: The overall allele pattern and acetylator status distribution in Iranians displayed the considerable prevalence of "slow acetylators" over "rapid acetylators," similar to those of Caucasians except for a minor difference observed in the frequency of the NAT2*7 allele. Nucleic acid testing for common NAT2 mutations might be a potentially useful tool for an accurate phenotype interpretation and identification of Iranian individuals at risk.