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Abnormal behavior associated with a point mutation in the structural gene for monoamine oxidase A
H G Brunner1, M Nelen, X O Breakefield
1Department of Human Genetics, University Hospital Nijmegen, The Netherlands.
Science (New York, N.Y.)
|October 22, 1993
Summary
Genetic studies revealed a link between a specific enzyme deficiency and abnormal behavior in males. This research highlights the role of monoamine oxidase A (MAOA) deficiency in impulsive aggression and other behavioral issues.
Area of Science:
- Neurogenetics
- Behavioral Genetics
- Metabolic Disorders
Background:
- A large kindred presented with a syndrome of borderline mental retardation and abnormal behaviors.
- Affected males exhibited impulsive aggression, arson, attempted rape, and exhibitionism.
Purpose of the Study:
- To investigate the genetic and metabolic basis of a behavioral syndrome in a kindred.
- To identify the specific molecular cause of the observed behavioral abnormalities.
Main Methods:
- Genetic analysis of affected individuals.
- Metabolic profiling using 24-hour urine samples.
- Enzymatic activity assays for monoamine oxidase A (MAOA).
Main Results:
- Markedly disturbed monoamine metabolism was observed in affected males.
- A complete and selective deficiency of monoamine oxidase A (MAOA) enzymatic activity was identified.
- A point mutation in the MAOA gene (eighth exon) was found in all five affected males, leading to a glutamine to termination codon change.
Conclusions:
- Isolated complete MAOA deficiency is associated with a distinct behavioral phenotype.
- The identified MAOA gene mutation is causative for the syndrome.
- Disturbed regulation of impulsive aggression is a key feature of this MAOA deficiency syndrome.