EVIDENCE FOR A GENETIC ASSOCIATION BETWEEN ALLELES OF MONOAMINE-OXIDASE A GENE AND BIPOLAR AFFECTIVE-DISORDER

We present evidence of a genetic association between bipolar disorder and alleles at 3 monoamine oxidase A (MAOA) markers, but not with alle les of a monoamine oxidase B (MAOB) polymorphism, The 3 MAOA markers, including one associated with low MAOA activity, show strong allelic a ssociation with each other but surprisingly not with MAOB, Our results are significant only for females, though the number of males in our s ample is too small to draw any definite conclusions, Our data is consi stent with recent reports of reduced MAOA activity in patients with ab normal behavioral phenotypes, The strength of the association is weak, but significant, which suggests that alleles at the MAOA locus contri bute to susceptibility to bipolar disorder rather than being a major d eterminant. (C) 1995 Wiley-Liss, Inc.