ASSOCIATION OF MONOAMINE-OXIDASE (MAO) ACTIVITY WITH ALCOHOLISM AND ALCOHOLIC SUBTYPES

A familial/genetic study of platelet monoamine oxidase (MAO) activity in alcoholics was carried out. MAO activities were determined using ph enylethylamine (PEA) as substrate at K-m concentration (1.2 mu M) and at saturating concentration (12.0 mu M). Complex segregation analysis of familial data indicated a single major gene mode of transmission of activity at both substrate concentrations. In addition, the present s ample size (13 families, 108 members) proved sufficient to allow corre lation analysis of enzyme activity with affection status and clinical subtypes of affecteds. MAO activity was significantly correlated with alcoholism at both K-m and saturating substrate concentrations and a s ignificant correlation between low MAO activity and Cloninger Type II alcoholism was seen at K-m substrate concentration. These results conf irm a hierarchical cosegregation of platelet MAO activity and alcoholi sm suggesting that MAO activity warrants continued status as a marker in alcoholism. (C) 1993 Wiley-Liss, Inc.