Arylamine N-acetyltransferase (NAT2) genotypes in Africans:: the identification of a new allele with nucleotide changes 481C>T and 590G>A

This study was carried out to characterize the distribution of NAT2 allelic variants among a sample of three African populations. We determined the frequencies of major NAT2 allele clusters (NAT2*5, * 6, * 7 and * 14) using PCR/restriction fragment length polymorphism and sequencing techniques. The genotypes predict slow acetylator phenotypes of 49, 38 and 52% among Tanzanians, Venda and Zimbabweans, respectively. The most common genotype was NAT2*4/*5. NAT2*5 was the most common allele while NAT2*7 was the least common. A new allele with two base changes occurring together, 481 C>T and 590G>A, is reported. The frequency of the occurrence of the combination 481 C>T and 590G>A, was found to be 9% (30/326),7% (14/192) and 8% (18/234) among Zimbabweans, Venda and Tanzanians, respectively. The allele has been named NAT2*6E. Among Africans, the change 481 C>T is not only associated with 341 C>T (i.e. the NAT2*5 allele cluster) as in other populations, but also with 590G>A on the same allele.