Brunner H G
Department of Human Genetics, Nijmegen University Hospital, The Netherlands.
Ciba Found Symp. 1996;194:155-64; discussion 164-7. doi: 10.1002/9780470514825.ch9.
We have recently described an association between abnormal behaviour and monoamine oxidase A (MAOA) deficiency in several males from a single large Dutch kindred. Affected males differed from unaffected males by borderline mental retardation and increased impulsive behaviour (aggressive behaviour, abnormal sexual behaviour and arson). Nevertheless, a specific psychiatric diagnosis was not made in four affected males who had psychiatric examination. Since MAOA deficiency raises 5-hydroxytryptamine (5-HT) levels, it provides an interesting exception to the low 5-HT paradigm of impulsive aggression. Even if the possible relationship between MAOA deficiency and abnormal behaviour is confirmed in other kindreds, the data do not support the hypothesis that MAOA constitutes an "aggression gene'. In fact, because genes are essentially simple and behaviour is by definition complex, a direct causal relationship between a single gene and a specific behaviour is highly unlikely. In the case of MAOA deficiency, some of the complexities are illustrated by the variability in the behavioural phenotype, as well as by the highly complex effects of MAOA deficiency on neurotransmitter function. Thus, the concept of a gene that directly encodes behaviour is unrealistic.
我们最近描述了来自一个荷兰大家族的几名男性中，异常行为与单胺氧化酶A（MAOA）缺乏之间的关联。受影响的男性与未受影响的男性的区别在于边缘智力迟钝和冲动行为增加（攻击行为、异常性行为和纵火）。然而，接受精神检查的四名受影响男性并未作出特定的精神病学诊断。由于MAOA缺乏会提高5-羟色胺（5-HT）水平，这为冲动攻击的低5-HT范式提供了一个有趣的例外情况。即使MAOA缺乏与异常行为之间的可能关系在其他家族中得到证实，这些数据也不支持MAOA构成“攻击基因”这一假设。事实上，由于基因本质上是简单的，而行为根据定义是复杂的，单个基因与特定行为之间的直接因果关系极不可能。就MAOA缺乏而言，行为表型的变异性以及MAOA缺乏对神经递质功能的高度复杂影响说明了其中一些复杂性。因此，直接编码行为的基因概念是不现实的。
