Brunner syndrome
Brunner syndrome | |
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Classification and external resources | |
Specialty | Lua error in Module:Wikidata at line 446: attempt to index field 'wikibase' (a nil value). |
OMIM | 300615 |
DiseasesDB | 32391 |
Patient UK | Brunner syndrome |
Brunner syndrome is hypothesized rare genetic disorder caused by a mutation in the MAOA gene. It is characterized by lower than average IQ (typically about 85), problematic impulsive behavior (such as arson, hypersexuality and violence), sleep disorders and mood swings.[1][2] It was identified in fourteen males from one family in 1993.[1][3] It has since been discovered in two additional families.[4]
Causes
Brunner syndrome is caused by a monoamine oxidase A (MAOA) deficiency, which leads to an excess of monoamines in the brain, such as serotonin, dopamine, and norepinephrine (noradrenaline). In both mice and humans, a mutation was located on the eighth exon of the MAO-A gene, which created a dysfunctional MAO-A gene.[5][6] The regular function of MAO-A, breaking down monoamines, is disrupted, and monoamines build up within the brain. Mice that lacked a functional MAO-A gene displayed higher levels of aggression, in comparison to mice with a functional MAO-A gene.[6]
History
Brunner Syndrome was described in 1993 by H.G. Brunner et al upon the discovery of a particular genetic defect in male members of a large Dutch family.[5] Brunner found that all of the male family members with this defect reacted aggressively when angry, fearful, or frustrated. The defect discovered was later found to be a mutation in the gene that codes for monoamine oxidase A (MAOA gene).[5] Brunner said that an "MAO-A deficiency is associated with a recognizable behavioural phenotype that included disturbed regulation of impulsive aggression".[5]
A letter published by Hebebrand and Klug (1995)[7] criticized Brunner's findings for not using strict DSM criteria.
Society and culture
Brunner's findings have been used to argue that genetics, rather than decision-making processes, can cause criminal activity.[8] Evidence supporting the genetic defense stems from both Brunner's findings and a series of studies on mice.[9] To prove the correlation between MAO-A deficiency and aggression in courts, it is often contended that individuals cannot be held accountable for their genes, and as a result, should not be held responsible for their dispositions and resulting actions.[8][9]
References
- ↑ 1.0 1.1 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Online 'Mendelian Inheritance in Man' (OMIM) 300615
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