rs1229984

rs1229984 is a missense variant in ADH1B causing an arginine-to-histidine substitution (His48, historically numbered Arg47His) in alcohol dehydrogenase 1B, the liver enzyme that oxidizes ethanol to acetaldehyde. The His48 allele has substantially higher catalytic activity than the ancestral Arg form, causing much faster conversion of ethanol to acetaldehyde and the associated flushing, nausea, and rapid-intoxication response; it is common in East Asian populations and is protective against alcohol dependence. It is used directly to describe individual variation in the speed of alcohol metabolism.