The genic variants homozygotes for ADH2*2, ADH3*1 and CYP2RB digested by RsaI c2 are isoforms with great activity enzymatic, whereas polymorphism ALDH2*2 is one isoform with loss or null activity, this suggests one modulation of the metabolism of the ethanol and acetaldehyde that they influence in the pharmacokinetics of the alcohol consumption that it takes to a possible protection or predisposition to the alcoholism in some populations like for example those of the Far Asia, Mexican, Israelite Asquenazí, Sefardites and Russian immigrants 3. This evidence concerns the gene ALDH2 and alcohol dependence.