Project:Alcohol Flush Genotyping: Difference between revisions

''ALDH2'' is a ~43 kb gene on chromosome 12 consisting of 13 exons and encodes the ALDH2 enzyme found in the mitochondria, it has two alleles ''ALDH2*1'' and ''ALDH2*2''. The [http://www.ncbi.nlm.nih.gov/SNP/snp_ref.cgi?rs=rs671 rs671 SNP] ([[#rs671 FASTA sequence|FASTA]]), in which a guanine in the ancestral ''ALDH2*1'' is substituted for an adenine in ''ALDH2*2'' is responsible for these two alleles. The G -> A substitution in ''ALDH2*2'' causes the amino acid lysine to be expressed instead of glutamate and causes an inactive ALDH2 enzyme to be expressed. ''ALDH2*2'' is considered nearly dominant as heterozygous individuals have almost no detectable ALDH2 activity in the liver and people who carry two copies of the ''ALDH2*2'' allele have no detectable activity.

''ALDH2*2'' is relatively common in people of Chinese, Japanese, and Korean descent but is essentially absent in people of European or African descent and is strongly associated with a drastic reduction in the likelihood of an individual becoming alcohol dependent.