Lesch-Nyhan syndrome

Definition

Lesch-Nyhan syndrome is a disorder passed down through families 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, incidence, and risk factors

Lesch-Nyhan syndrome is passed down through families (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 substance to recycle purines. Without it, abnormally high levels of uric acid build up in the body.

Symptoms

Too much uric acid can cause gout-like swelling in some of the joints. In some cases, kidney and bladder stones develop.

Males with Lesch-Nyhan have delayed motor development followed by abnormal movements and increased reflexes. A striking feature of Lesch-Nyhan syndrome is self-destructive behavior including chewing off fingertips and lips. It is unknown how the disease causes these problems.

Signs and tests

There may be a family history of this condition.

The doctor or nurse will perform a physical exam. The exam may show:

Blood and urine tests may show high uric acid levels. A skin biopsy may show decreased levels of the HGP enzyme.

Treatment

No specific treatment exists for Lesch-Nyhan syndrome. Gout medication (allopurinol) can lower uric acid levels. However, treatment does not improve the neurological outcome.

Some symptoms may be relieved with the following medicines:

  • Carbidopa/levodopa
  • Diazepam
  • Phenobarbital
  • Haloperidol

Expectations (prognosis)

The outcome is likely to be poor. Persons with this syndrome usually need help walking and sitting and generally need a wheelchair.

Complications

Severe, progressive disability is likely.

Calling your health care provider

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 JC. Disorders of purine and pyrimidine metabolism. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 83.

Revision

Last reviewed 5/16/2012 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. Health Solutions, Ebix, Inc.

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