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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

Support Groups

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. 19th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 83.

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    Encyclopedia content is provided as information only and not intended to replace the advice and instruction from your personal physician.