Lesch-Nyhan syndrome
Definition
Lesch-Nyhan syndrome is a disorder that is passed down through families (inherited). It affects how the body builds and breaks down chemicals called purines. Purines are a normal part of human tissue that help make up the body's genetic blueprint. They are also found in many different foods.
Causes
Lesch-Nyhan syndrome is passed down as an X-linked, or sex-linked trait. It occurs mostly in boys. People with this syndrome are missing or severely lacking an enzyme called hypoxanthine guanine phosphoribosyltransferase (HPRT). 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.
People 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.
Exams and Tests
There may be a family history of this condition.
The health care provider will perform a physical exam. The exam may show:
- Increased reflexes
- Spasticity (having spasms)
Blood and urine tests may show high uric acid levels. A skin biopsy may show decreased levels of the HPRT1 enzyme.
Treatment
No specific treatment exists for Lesch-Nyhan syndrome. Medicine for treating gout can lower uric acid levels. However, treatment does not improve the nervous system outcome (for example, having increased reflexes and spasms).
Some symptoms may be relieved with these medicines:
- Carbidopa/levodopa
- Diazepam
- Phenobarbital
- Haloperidol
Self-harm can be reduced by removal of teeth or by using a protective mouth guard designed by a dentist.
You can help a person with this syndrome using stress-reduction and positive behavioral techniques.
Outlook (Prognosis)
The outcome is likely to be poor. People with this syndrome usually need help walking and sitting. Most need a wheelchair.
Possible Complications
Severe, progressive disability is likely.
When to Contact a Medical Professional
Contact your 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, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:chap 108.
Katz TC, Finn CT, Stoler JM. Patients with genetic syndromes. In: Stern TA, Freudenreich O, Smith FA, Fricchione GL, Rosenbaum JF, eds. Massachusetts General Hospital Handbook of General Hospital Psychiatry. 7th ed. Philadelphia, PA: Elsevier; 2018:chap 35.
Paller AS, Mancini AJ. Inborn errors of metabolism. In Paller AS, Mancini AJ, eds. Paller and Mancini � Hurwitz Clinical Pediatric Dermatology. 6th ed. St Louis, MO: Elsevier; 2022:chap 24.
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Review Date:
2/17/2024 Reviewed By: Charles I. Schwartz, MD, FAAP, Clinical Assistant Professor of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, General Pediatrician at PennCare for Kids, Phoenixville, PA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team. |
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