Frequency of ALDH2 Gene Polymorphism (rs671) in Dayak, Javanese, Minahasan, and Papuan Ethnic Populations

The rs671 is a single nucleotide polymorphism in the ALDH2 gene which resulted in the ALDH2 enzyme inactive so that the acetaldehyde detoxification is disrupted. Individuals carrying the ALDH2*2 allele are at increased risk of diseases associated with alcohol consumption. The rs671 polymorphism is very common in East Asia and is strongly suspected to originate from the Han-Chinese ethnic group. Research in Indonesia shows that the frequency of ALDH2*2 alleles is quite wide and high (15.5 to 72.6%). This raises the question of why the prevalence of the ALDH2*2 allele in Indonesia is much higher than China. The aim of this study was to determine the genotypic and allele frequencies of rs671 of Indonesian with different ethnic background, namely the Dayak, Javanese, Minahasan and Papuan ethnic groups. SNP rs671 was detected by the Taqman SNP genotyping assay method using the QuantStudio 5 Applied Biosystems real-time PCR. The genotypic frequencies of typical homozygous, heterozygous, and atypical homozygous in the Minahasan ethnic group were 97.8%, 2.2% and 0%, respectively. The frequency of the ALDH2*2 allele is only 1.1%. The genotypic frequencies of the Dayak, Javanese and Papuan ethnic groups were 100% typical homozygotes (ALDH2*1/*1), the ALDH2*2 allele was not found. This study shows that rs671 is very rarely found among Indonesian with different ethnic background. The results of this study are in accordance with distribution patterns in East Asia, Southeast Asia and Oceania.