Abnormal behavior associated with a point mutation in the structural gene for monoamine oxidase A

Science. 1993 Oct 22;262(5133):578-80. doi: 10.1126/science.8211186.


Genetic and metabolic studies have been done on a large kindred in which several males are affected by a syndrome of borderline mental retardation and abnormal behavior. The types of behavior that occurred include impulsive aggression, arson, attempted rape, and exhibitionism. Analysis of 24-hour urine samples indicated markedly disturbed monoamine metabolism. This syndrome was associated with a complete and selective deficiency of enzymatic activity of monoamine oxidase A (MAOA). In each of five affected males, a point mutation was identified in the eighth exon of the MAOA structural gene, which changes a glutamine to a termination codon. Thus, isolated complete MAOA deficiency in this family is associated with a recognizable behavioral phenotype that includes disturbed regulation of impulsive aggression.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Aggression*
  • Cell Line
  • Cells, Cultured
  • Female
  • Genes*
  • Humans
  • Intellectual Disability / enzymology
  • Intellectual Disability / genetics*
  • Male
  • Monoamine Oxidase / deficiency
  • Monoamine Oxidase / genetics*
  • Pedigree
  • Phenotype
  • Point Mutation*
  • Skin / enzymology
  • Syndrome
  • X Chromosome


  • Monoamine Oxidase