Genotype-phenotype agreement of aldehyde dehydrogenase 2 in 120 healthy Japanese.

An individual genotype of aldehyde dehydrogenase 2 was observed using nail clippings by an improved method consisting of DNA extraction with guanidium thiocyanate, genomic DNA amplification by non-isotopic polymerase chain reaction, and gel electrophoresis of the DNA fragment. The results were consistent with those obtained using the corresponding peripheral blood samples. The individual phenotype was also determined by the Tokyo-University ALDH2-Phenotype Screening Test. Both types of ALDH2 were observed in 120 healthy Japanese and 48% were the typical or normal homozygote, 43% were the heterozygote, and 9% were the atypical or mutant homozygote of ALDH2. Among 57 individuals of both sexes with the typical homozygote, 88% were the phenotype of a non-flusher. Similarly 76% of the 63 heterozygote/atypical homozygotes had the phenotype of a flusher.