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Lesch-Nyhan syndrome
Definition
Lesch-Nyhan syndrome is an inheritable disorder that affects how the body builds and breaks down purines. Purines are a normal part of human tissue and help make up the body's genetic blueprint. They are also found in many different foods.
Causes
Lesch-Nyhan syndrome is inherited as an X-linked trait. It mostly occurs in boys. Persons with this syndrome are missing or are severely lacking an enzyme called hypoxanthine guanine phosphoribosyltransferase 1 (HGP). The body needs this enzyme to recycle purines. Without it, abnormally high levels of uric acid build up in the body.
The condition affects about 1 in 380,000 people.
Symptoms
The excess uric acid levels cause children to develop gout-like swelling in some of their joints. In some cases, kidney and bladder stones develops because of the high uric acid levels.
Males with Lesch-Nyhan have delayed motor development followed by bizarre, sinuous movements and increased deep tendon reflexes. A striking feature of Lesch-Nyhan syndrome is self-destructive behavior characterized by chewing off fingertips and lips, if not restrained. It is unknown how the enzyme deficiency causes these problems.
Exams and Tests
There may be a family history of this condition.
The doctor will perform a physical exam. The exam may show:
Blood and urine tests may reveal high uric acid levels. Askin biopsy may show decreased levels of the HGP enzyme.
Treatment
No specific treatment exists for Lesch-Nyhan syndrome. The gout medication allopurinol successfully decreases uric acid levels, but does not improve the neurological outcome.
Some symptoms may be relieved with the drugs carbidopa/levodopa, diazepam, phenobarbital, or haloperidol.
Outlook (Prognosis)
The outcome is likely to be poor. Persons with this syndrome usually require assistance walking and sitting and generally need a wheelchair to get around.
Possible Complications
Severe, progressive disability is likely.
When to Contact a Medical Professional
Call your health care provider if signs of this illness appear in your child or if there is a history of Lesch-Nyhan syndrome in your family.
Prevention
Genetic counseling for prospective parents with a family history of Lesch-Nyhan syndrome is recommended. Testing can be done to see if a woman is a carrier of this syndrome.
References
Harris J. Disorders of Purine and Pyrimidine Metabolism.In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 18th ed. Philadelphia, Pa: Saunders Elsevier; 2007: Chap. 89.
Review Date:
5/8/2008
Reviewed By:
Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc. The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997-
A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited. | 
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