Gene Therapy Correction of Aldehyde Dehydrogenase 2 Deficiency

Aldehyde dehydrogenase 2 (ALDH2) deficiency causes "Asian flush syndrome," presenting as alcohol-induced facial flushing, tachycardia, nausea, and headaches. One of the most common hereditary enzyme deficiencies, it affects 35%-40% of East Asians and 8% of the world population. ALDH2 is the key enzyme in ethanol metabolism; with ethanol challenge, the common ALDH2*2 (E487K) mutation results in accumulation of toxic acetaldehyde. heterozygotes have increased risk for upper digestive tract cancers, compounded by smoking and drinking alcohol. We hypothesized that a one-time administration of an adeno-associated virus (AAV) gene transfer vector expressing the human coding sequence (AAVrh.10hALDH2) would correct the deficiency state. AAVrh.10hALDH2 was administered intravenously to knockout ( ) and E487K knockin homozygous ( ) mice. Following acute ethanol ingestion, untreated ALDH2-deficient mice had elevated acetaldehyde levels and performed poorly in behavioral tests. In contrast, treated and mice had lower serum acetaldehyde levels and improved behavior. Thus, AAV-mediated ALDH2 therapy may reverse the deficiency state in individuals, eliminating the Asian flush syndrome and reducing the risk for associated disorders.