[Investigation for polymorphism of ALDH2 exon12 in several Asian areas].

Mitochondrial aldehyde dehydrogenase (ALDH2) shows genetic polymorphism (Glu487Lys substitution) among Mongoloid populations, and the substitution is responsible for flushing symptom after alcohol intake. Recently, new ALDH2 alleles (ALDH23 and ALDH22Taiwan) in exon12 were reported in North American Indians and in Chinese from Taiwan by Novoradskey et al (1995). In the present study, we investigated the new allelic variants in exon12 for the five different ethnic groups (Mongolian, North Chinese, South Chinese, Myanmar, Japanese) by using PCR-SSCP and PCR-direct sequencing. Also, Glu 487 Lys substitution was analyzed to obtain additional information on gene geography of ALDH2 alleles in Asia reported so far. No new variants were found in the five population groups, but ALDH22 allele showed different frequencies among these groups. Especially, the frequencies of ALDH22 in Myanmer (0.02) and Mongolian (0.05) were significantly lower than other populations.