Table 2.

The five phase-resolved NAT2 molecular data sets investigated.

Population sample	Proportion of phase-unknown multiple heterozygotesa	NAT2 gene diversityb	Deviation from the Hardy-Weinberg equilibrium (exact p-value)c
258 Spanish [45]	66.7%	0.65	0.012
137 Nicaraguans [30]	59.1%	0.70	0.072
112 UK Caucasians [24]	52.7%	0.69	0.222
101 Black South Africans [24]	63.4%	0.86	0.122
1000 Koreans [31]	50.0%	0.52	0.016

All population samples were genotyped for the same seven nucleotide changes (G191A, C282T, T341C, C481T, G590A, A803G, G857A), except Koreans where the C190T mutation was investigated instead of G191A.

^aProportion of multiply heterozygous individuals with ambiguous genotype whose phase has been resolved molecularly.

^bExpected heterozygosities for the NAT2 haplotyped system were estimated as where n is the number of gene copies in the sample, and pi is the sample frequency of the i-th haplotype.

^cThe significance of deviations from Hardy-Weinberg equilibrium was tested for genotypic data with known gametic phase using the random-permutation procedure implemented in the Arlequin package [51]: a Fisher's exact test using a Markov chain random walk algorithm was performed for each data set. The resulting p-values were considered significant if inferior to 0.05 (significant p-values are shown in bold).