Expert: Chris - 11/30/2002

Question
I am a non-scientist, and this is not an academic question.  I read about the "crime gene".  Is it theoretically possible (IN FUTURE), through technology not yet conceivable, to eliminate such gene from human system, or even a specific individual?

Answer
Hi, I'm afraid there is no such thing as a "crime" gene. What you are probably referring to is a gene called MAO (monoamine oxidase). There has been one (human) family where both copies of hte gene was mutated: the males were profoundly mentally retarded, violent, and prone to commit arson and rape. However, you must realise that this is not a "crime" gene. Rather, this behaviour results from an inbalance in "brain chemistry" caused by the defective genes. Remember, these individuals are profoundly mentally retarded. In mouse models of this condition, the mice are more aggressive, and do not seem to be able to regulate their behaviour the way normal mice are thought to.

Genes give us tendencies - we are more or less likely to have a trait if we have one version of a gene rather than another. In only a very few cases is the gene linked categorically to a result - if you have this version, you will have this condition. So the idea of a "crime" gene is absurd. Our environment (ie any non-genetic factors we experience) is at least as important in how we behave as our genes.

As to whether we could eliminate a gene: not really. A major stumbling block is that you would have to alter every cell in a human body to remove or alter a gene - that's about 5 billion cells! Impossible. You could do it via IVF, where embryos are screened for certain gene variants, and rejected if they have them; however, because most genetic effects are probabilistic (ie they give us a greater/lesser chance of having something), you cannot be sure - at best you would have a percentage based on a wide population.

Hope this helps

Chris