Approximately 45% of East Asians, particularly Japanese, are carriers of the ALDH2*2 allele (Glu504Lys, rs671) that encodes the inactive ALDH2 enzyme. After consumption of small quantities of alcohol by these individuals the toxin acetaldehyde rapidly accumulates, resulting in the very unpleasant flushing syndrome (facial flushing, tachycardia, sweating, headaches, nausea), colloquially called ‘Asian Glow’ or ‘Asian Blush’, that is protective against heavy drinking and therefore alcoholism [20]. The inactive ALDH2 variant is also associated with increased risk of esophageal cancer [21]. The ALDH2*2 allele is unique to East Asian populations.
