One of the most bizarre congenital birth defects is Lesch-Nyhan Syndrome. This is an X-linked recessive disorder that is caused by a nearly complete absence of the enzyme HPRT, which results in an extreme overproduction of uric acid and the related symptoms of gout and renal dysfunction. In addition, all patients have neurological abnormalities including involuntary spastic movements, difficulty in articulating words, and (of the greatest fascination) a unique compulsion to self-injure, abuse others (physically and verbally) and to lie and curse. (Hmmmm... perhaps Dick Cheney should be tested for this?) The symptoms are so severe that patients are unable to sit or stand without assistance. The muscles controlling vocal production are similarly affected and their speech can be understood only with great difficulty. Self-injury starts as young as 2 years of age with lip and finger biting being the most typical. As they grow older, patients injure themselves in any way they can devise! (Is it any wonder there's a metal band called Lesch-Nyhan?)
Generally, the first symptom of Lesch-Nyhan Disease is "orange sand" in the diapers, which can occur with babies as young as one week of age. This is a symptom of accumulation of uric acid leading to secretion of urinary urate. By three months of age developmental problems become noticeable. The first sign is usually a "limp baby" unable to lift his head. By six months the parents may notice an unusual arching of the back. At nine months they are unable to pull themselves into a standing position and do not crawl. At twelve months they are not walking and by eighteen months they evidence involuntary movements that seem jerky and twisting and have odd posturing of the arms and legs and torso.
Self-mutilating behavior is the hallmark of this disease. Children begin to bite their fingers, lips, and the insides of their mouths as early as 2 years of age. As children grow, self-injury becomes increasingly compulsive and severe. Eventually, mechanical physical restraints will be necessary to prevent head and leg banging, nose gouging, loss of fingers and lips from biting, loss of vision from eye rubbing, etc. In addition to self-injury, older children and teens will become physically and verbally aggressive. Many patients have their teeth extracted to eliminate the danger caused by biting. For some patients, the less extreme measure of wearing dental guards can be used instead.
The cause of these bizarre behaviors is not entirely understood. However, some experts believe it is related to abnormalities in brain chemicals called neurotransmitters. It is apparent that the child does not want to hurt himself or others, but is incapable of preventing these behaviors. People with Lesch-Nyhan syndrome have been described as doing the opposite of what they really want.
The average life expectancy is somewhere in the early to mid twenties. Kidney failure was once the main cause of death but medication can now control the damage to kidneys and patients are living much longer lives. Intellectually, those suffering from this syndrome are reasonably intact. They have an excellent memory, their emotional life is appropriate, they have good concentration, they are capable of abstract reasoning, they have good self-awareness and are highly social.