Psychology

To explain the behaviour of a large family in the Netherlands, where the males are affected by a syndrome of borderline mental retardation and abnormal violent behaviour.

• 5 males of the family.
• Data collection from analysis of urine over 24 hours.

• Showed a deficit of the enzyme monoamine oxidase A. MAOA.
• A mutation in the X chromosome of the gene was responsible for production of Monoanime oxidase A.

Serotonin metabolism.

responsible for the mental retardation in the family and in turn account for the violent behaviour.

Monoamine oxidase A deficiency accounted for their inability to regulate their aggression.