This man’s face has flushed red after drinking alcohol. A harmless enough side-effect, one might think, but it’s actually a tell-tale sign of a genetic abnormality – a sign that might save his life. Up to 36% of people from East Asia experience ‘alcohol flushing’ due to a genetic mutation affecting an enzyme called aldehyde dehydrogenase-2 (ALDH2). ALDH2 is required to fully break down (metabolise) alcohol – having insufficient ALDH2 leaves the reaction incomplete, turning the alcohol to acetaldehyde, a harmful carcinogen. Alcohol drinkers deficient in ALDH2 have a vastly increased risk of developing throat cancers such as squamous cell carcinoma. For the estimated 8% of the world’s population who are ALDH2-deficient, facial flushing is a clear sign to stay off the booze, and may save thousands of lives.
Written by John Ankers
BPoD stands for Biomedical Picture of the Day. Managed by the MRC London Institute of Medical Sciences the website aims to engage everyone, young and old, in the wonders of biomedicine. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.
BPoD is also available in Catalan at www.bpod.cat with translations by the University of Valencia.