Lesch-Nyhan syndrome is a genetic disorder. It affects the metabolism of purines in the body. Purines are protein molecules that are important for the metabolism of RNA and DNA, which make up our genetic codes. Lesch-Nyhan syndrome is characterized by uric acid build-up, neurologic disability,
behavioral problems, including
self-injury. It is a rare condition.
Lesch-Nyhan syndrome is caused by a mutation or change in a gene. This change results in the absence of the enzyme hypoxanthine-guanine phosphoribosyltransferase (HPRT). HPRT is needed to metabolize uric acid. Without this enzyme, uric acid builds up in the central nervous system, kidneys, and other areas of the body.
This gene mutation occurs on the X chromosome. It can either be a new mutation in the affected person or inherited from the person's mother, who is a carrier.
Lesch-Nyhan syndrome is more common in men. Having male family members with Lesch-Nyhan syndrome (on the mother's side) also increases the risk.
The first symptom of Lesch-Nyhan syndrome
orange-colored crystal-like deposits in the diaper. This may occur in children as young as 3 months. These deposits are caused by increased uric acid in the urine. Other symptoms include:
Nervous system impairment:
4 to 6 months—lack of muscle tone and inability to lift the head
6 months—unusual arching of the back
9 months—inability to crawl or stand
12 months—inability to walk
12+ months—spasms of the limbs and facial muscles
Behavioral problems occur in all cases and self injury in about 85%
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 old.
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, and loss of vision from eye rubbing, among others. In addition to self-injury, older children and teens will become physically and verbally aggressive.
The cause of these behaviors is not entirely understood. However, some experts believe it is related to abnormalities in brain chemicals called neurotransmitters. It should be stressed 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.
You will be asked about your child's symptoms, behavior traits, and medical history. A physical exam will be done.
Your child's bodily fluids may be tested. This can be done with blood tests. Reduced levels of the HPRT enzyme will confirm the diagnosis.
There is no treatment to cure Lesch-Nyhan. However,
good hydration and
certain medications may help to alleviate some of its symptoms. These may include:
The following medications may be used:
Allopurinol—to control excessive levels of uric acid in the body
Medications to reduce muscle spasms
Behavioral problems may also be managed with a combination of behavioral modification techniques and medication.
S-adenosylmethionine—2 reports suggests that administration of s-adenosylmethionine, a food supplement, may reduce self-mutilating behaviors in adults with this syndrome. This supplement, which is available in health food stores, is naturally synthesized by the human body and important for many bodily processes. Talk to a doctor before taking any supplements.
With treatment, the average life expectancy is early- to mid-20s. There may be an increased risk of sudden death due to respiratory causes. However, many people live longer with good medical and psychological care.
There are no guidelines to prevent Lesch-Nyhan syndrome. If you have a family history of this condition, you can talk to a genetic counselor when deciding whether to have children.
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