Impact of population diversity on the prediction of 7-SNP NAT2 phenotypes using the tagSNP rs1495741 or paired SNPs.

A novel NAT2 tagSNP (rs1495741) and a 2-SNP genotype (rs1041983 and rs1801280) have been recently shown to accurately predict the NAT2 acetylator phenotypes in populations of exclusive or predominant European/White ancestry. We confirmed the accuracy of the tagSNP approach in White Brazilians, but not in Brown or Black Brazilians, sub-Saharan Mozambicans, and Guarani Amerindians. The combined rs1041983 and rs1801280 genotypes provided considerably better prediction of the NAT2 phenotype in Guarani, but no consistent improvement in Brown or Black Brazilians and Mozambicans. Best predictions of the NAT2 phenotype in Mozambicans using NAT2 SNP pairs were obtained with rs1801280 and rs1799930, but the accuracy of the estimates remained inadequate for clinical use or for investigations in this sub-Saharan group or in Brazilians with considerable African ancestry. In conclusion, the rs1495741 tagSNP cannot be applied to predict the NAT2 acetylation phenotype in Guarani and African-derived populations, whereas 2-SNP genotypes may accurately predict NAT2 phenotypes in Guarani, but not in Africans.