Lesch-Nyhan syndrome

• Causes, incidence, and risk factors

  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 develop 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.

• Signs and tests

  There may be a family history of this condition.

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

  • Overexaggerated reflexes
  • Spasticity

  Blood and urine tests may reveal high uric acid levels. A skin 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.

• Expectations (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.

• 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 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.