Because the ALDH2*504Lys allele reduces activity in heterozygotes, though with a less severe phenotype than homozygous ALDH2*504Lys individuals, we have also considered the combined distribution of both homozygotes and heterozygotes (i.e., 2pq + q2). Figure 2 shows the distribution of this ALDH2*504Lys “carrier” frequency. The high frequency area of the “carriers” is much wider than the high frequency area of the allele, as expected, indicating that more populations may be at risk for the associated disorders.
