Rs671

rs671 is a classic SNP, well known in a sense through the phenomena known as the "alcohol flush", also known as the "Asian Flush" or "Asian blush", in which certain individuals, often of Asian descent, have their face, neck and sometimes shoulders turn red after drinking alcohol.

The rs671(A) allele of the ALDH2 gene is the culprit, in that it encodes a form of the aldehyde dehydrogenase 2 protein that is defective at metabolizing alcohol. This allele is known as the ALDH*2 form, and individuals possessing either one or two copies of it show alcohol-related sensitivity responses including facial flushing, and severe hangovers (and hence they are usually not regular drinkers). Perhaps not surprisingly they appear to suffer less from alcoholism and alcohol-related liver disease. [PMID 511165, PMID 16046871]

Disulfiram (Antabuse) is probably an ineffective treatment for alcohol dependence in people who have the Asian Flush.

Tests for the alcohol flush reaction at deCODEme are based on rs671.

23andMe blog carriers of the A allele are prone to esophageal cancer, which is also known as upper aerodigestive tract (UAT) cancer, due to acetaldehyde from smoking.

Alcohol Consumption, Smoking and Risk of Esophageal Cancer