Table 3

Examples of NAT2 genotype/phenotype misclassifications

NAT2 genotypea (comprehensive)Deduced phenotypea (comprehensive)NAT2 genotypeb (simple)Deduced phenotypeb (simple)
*4/*5C Intermediate Wt/Wt Rapid
*4/*12C Rapid Wt/M1 Intermediate
*4/*14A Intermediate Wt/Wt Rapid
*4/*14B Intermediate Wt/Wt Rapid
*4/*14E Intermediate Wt/Wt Rapid
*5B/*5C Slow Wt/M1 Intermediate
*5B/*14A Slow Wt/M1 Intermediate
*5B/*14B Slow Wt/M1 Intermediate
*5C/*6A Slow Wt/M2 Intermediate
*5C/*7B Slow Wt/M3 Intermediate
*5C/*12A Intermediate Wt/Wt Rapid
*5C/*13 Intermediate Wt/Wt Rapid
*6A/*12C Intermediate M1/M2 Slow
*6A/*14A Slow Wt/M2 Intermediate
*6A/*14B Slow Wt/M2 Intermediate
*12A/*14B Intermediate Wt/Wt Rapid
*13/*14B Intermediate Wt/Wt Rapid
*14A/*14A Slow Wt/Wt Rapid
  • a Examples of NAT2 genotypes and deduced phenotypes from ongoing studies in our laboratory. The frequency of the genotypes varies with ethnic origin.

  • b The original NAT2 nomenclature identified a wild type (Wt) allele and three mutant M1, M2, and M3 alleles. Deduced phenotypes are defined as follows: rapid acetylators, Wt/Wt; intermediate acetylators, Wt/mutant; slow acetylators, mutant/mutant. A“ simple” NAT2 genotype method distinguishes only these alleles.