Fig. 1

The genetic variant ALDH2*2. The ALDH2*2 variant is present in 540 million people in the world mainly of Han Chinese descent. The variant is identifiable by the phenotypic response of facial flushing after alcohol consumption. People heterozygotic for the genetic variant (ALDH2 *1*2) have at least a 60 % decrease in enzymatic activity while those homozygotic (ALDH2 *2*2) have greater than a 95 % decrease in enzymatic activity