Monoamine oxidase-A deficiency is a very rare recessive X-linked biogenic amine metabolism disorder characterized clinically by mild intellectual deficit, impulsive aggressiveness, and sometimes violent behavior and presenting from childhood. The disease is Monarch Disease Ontology entry MONDO_0010379 (Brunner syndrome). Also known as: Brunner syndrome, X-linked recessive, antisocial behavior, X-linked recessive, monoamine oxidase A deficiency.