What a test can show
rs671 genotyping is especially informative in people of East Asian ancestry; ADH1B also contributes.
Common traits
ALDH2Alcohol flushing
Reduced-function variant rs671 can cause acetaldehyde accumulation, flushing and unpleasant symptoms after alcohol.
RELATIONSHIP VALIDITYStrong functional and population evidence
ACTIONABILITYA signal to avoid harmful exposure, not to calculate a ‘safe dose’
SOURCE CHECKLinks and claim boundaries are editorially checked; external expert review is stated only with named disclosure
Practical meaning
Flushing is not protection and should not be ‘trained away’: acetaldehyde is toxic.
Where knowledge ends
Absence of rs671 does not make alcohol safe or exclude flushing from other causes.
SOURCES AND VERSION
Verifiable, not ‘trust us’.
Updated: 14 August 2026. Any clinical interpretation requires the exact variant, testing method, family information and medical context.