GENETIC-POLYMORPHISM OF LIVER ALCOHOL-DEHYDROGENASE IN SPANISH SUBJECTS - SIGNIFICANCE OF ALCOHOL-CONSUMPTION AND LIVER-DISEASE

Class I alcohol dehydrogenase (ADH) phenotypes have been studied by st arch gel electrophoresis and activity analysis in liver tissue obtaine d at necropsy from 61 non-alcoholic subjects with normal liver (contro ls), and in biopsies from 60 chronic alcoholics with liver disease and from 24 subjects with non-alcoholic liver disease. Twenty-three per c ent of controls exhibited the ADH(2)(2-1) phenotype, which represents the highest frequency for atypical ADH found in a Caucasian population . Both alcoholic and non-alcoholic patients with liver disease showed a lower frequency of the atypical phenotype (6.6% and 8.8%, respective ly). No differences in the ADH(2) locus were detected among groups of patients with different severity of alcoholic and non-alcoholic liver disease. The allele frequencies of the ADH(3) locus for the controls ( ADH(3)(I) = 0.63, ADH(3)(2) = 0.37) are common to those of other Cauca sian populations. Similar ADH(3) allele frequencies were observed in p atients with alcoholic and non-alcoholic liver disease. Discrepancies between the various phenotyping and genotyping studies now known for s everal populations suggest that local differences may exist in the dis tribution of the ADH polymorphism in even geographically close regions , and that the effect of ADH polymorphism on vulnerability towards alc ohol may not be identical in different populations.