Bite Me
Recently I became aware of a genetic mutation in humans that produces something called Lesch-Nyhan syndrome. Seems that in the human genome of 20,000 to 25,000 active genes, approximately 99% of them are identical in all humans. The remaining 1%, or so, vary slightly, producing the uniqueness in each of us. In about 1 in 380,000 persons, the HPRT1 gene -- located between DNA base pairs 133,421,922 to 133,462,361 on the "X" chromosome -- is different by as little as a single base pair, resulting in males that exhibit Lesch-Nyhan syndrome.
The manifestation of these rare deviations from the norm in the HPRT1 gene appear in both physical and behavioral forms. On the physical side, the affected individuals are unable to walk, have involuntary muscle movements, are subject to gouty arthritis, kidney stones and bladder stones. They typically have reduced intellectual capacities. The deviate HPRT1 gene, which is responsible for recycling DNA material, allows abnormally large amounts of uric acid to be produced. Persons with Lesch-Nyhan typically die young, most before reaching 40 years of age.
The behavioral manifestations in affected individuals, however, are most remarkable and, of these, self mutilation is perhaps the most striking. Beginning at 2 or 3 years of age, persons with Lesch-Nyhan syndrome begin to uncontrollably bite away their fingers and lips. Some progress to destroying their nose, nasal passages and the roof of their mouth. Others bang their head against walls. At the most extreme, a few have even disgorged their eyes. They experience the same pain as would you or I. The only difference is that they cannot, of their own free will, stop themselves from performing these acts of self mutilation. They can -- and most do -- asked to be physically restrained and many have had their teeth extracted.
A second behavioral manifestation involves their interaction with other people. Specifically, they lash out at the very people they like most by cursing at them, spitting or vomiting on them, and acting aggressively toward them. In fact, those affected by Lesch-Nyham syndrome are kindest to those person they least like. Again, they are unable to control this behavior, of their own free will.
Like hemophilia, Lesch-Nylan Syndrome is an X-linked recessive genetic disorder: the gene is carried by the mother and passed on to her son. Unlike hemophilia, Lesh-Nylan produces behavioral characteristics over which the affected person has no free will to control.
So, here is the big question Lesch-Nylan Syndrome raises: If a mutation of as little as a single DNA base pair on a single gene can produce such a radical change in behavior over which the affected person has no control, how much of our behavior is genetically determined by the other hundreds of million of DNA base pairs in other tens of thousands of genes. More specifically, how much -- if any -- free will do we have in the conduct of our lives? How many other behaviors -- serial murder, alcohol and other drug abuse, homosexuality, child abuse, serial robbery, and the like -- that my be considered outside the behavioral norms of the societies in which they occur are genetically linked? And, finally, how do those societies deal with such behaviors that might prove to be genetically linked to the extent the affected have no free will to control them?
The manifestation of these rare deviations from the norm in the HPRT1 gene appear in both physical and behavioral forms. On the physical side, the affected individuals are unable to walk, have involuntary muscle movements, are subject to gouty arthritis, kidney stones and bladder stones. They typically have reduced intellectual capacities. The deviate HPRT1 gene, which is responsible for recycling DNA material, allows abnormally large amounts of uric acid to be produced. Persons with Lesch-Nyhan typically die young, most before reaching 40 years of age.
The behavioral manifestations in affected individuals, however, are most remarkable and, of these, self mutilation is perhaps the most striking. Beginning at 2 or 3 years of age, persons with Lesch-Nyhan syndrome begin to uncontrollably bite away their fingers and lips. Some progress to destroying their nose, nasal passages and the roof of their mouth. Others bang their head against walls. At the most extreme, a few have even disgorged their eyes. They experience the same pain as would you or I. The only difference is that they cannot, of their own free will, stop themselves from performing these acts of self mutilation. They can -- and most do -- asked to be physically restrained and many have had their teeth extracted.
A second behavioral manifestation involves their interaction with other people. Specifically, they lash out at the very people they like most by cursing at them, spitting or vomiting on them, and acting aggressively toward them. In fact, those affected by Lesch-Nyham syndrome are kindest to those person they least like. Again, they are unable to control this behavior, of their own free will.
Like hemophilia, Lesch-Nylan Syndrome is an X-linked recessive genetic disorder: the gene is carried by the mother and passed on to her son. Unlike hemophilia, Lesh-Nylan produces behavioral characteristics over which the affected person has no free will to control.
So, here is the big question Lesch-Nylan Syndrome raises: If a mutation of as little as a single DNA base pair on a single gene can produce such a radical change in behavior over which the affected person has no control, how much of our behavior is genetically determined by the other hundreds of million of DNA base pairs in other tens of thousands of genes. More specifically, how much -- if any -- free will do we have in the conduct of our lives? How many other behaviors -- serial murder, alcohol and other drug abuse, homosexuality, child abuse, serial robbery, and the like -- that my be considered outside the behavioral norms of the societies in which they occur are genetically linked? And, finally, how do those societies deal with such behaviors that might prove to be genetically linked to the extent the affected have no free will to control them?
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