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Lesch-Nyhan Syndrome
What is Lesch-Nyhan Syndrome?
Lesch-Nyhan syndrome (LNS) is a rare, inherited disorder caused by a
deficiency of the enzyme hypoxanthine-guanine phosphoribosyltransferase (HPRT).
LNS is an X-linked recessive disease-- the gene is carried by the mother and
passed on to her son. LNS is present at birth in baby boys. The lack of HPRT
causes a build-up of uric acid in all body fluids, and leads to symptoms such as
severe gout, poor muscle control, and moderate retardation, which appear in the
first year of life. A striking feature of LNS is self-mutilating behaviors –
characterized by lip and finger biting – that begin in the second year of life.
Abnormally high uric acid levels can cause sodium urate crystals to form in the
joints, kidneys, central nervous system, and other tissues of the body, leading
to gout-like swelling in the joints and severe kidney problems. Neurological
symptoms include facial grimacing, involuntary writhing, and repetitive
movements of the arms and legs similar to those seen in Huntington’s disease.
Because a lack of HPRT causes the body to poorly utilize vitamin B12, some boys
may develop a rare disorder called megaloblastic anemia.
Is there any treatment?
Treatment for LNS is symptomatic. Gout can be treated with allopurinol to
control excessive amounts of uric acid. Kidney stones may be treated with
lithotripsy, a technique for breaking up kidney stones using shock waves or
laser beams. There is no standard treatment for the neurological symptoms of LNS.
Some may be relieved with the drugs carbidopa/levodopa, diazepam, phenobarbital,
or haloperidol.
What is the prognosis?
The prognosis for individuals with LNS is poor. Death is usually due to
renal failure in the first or second decade of life.
What research is being done?
The gene associated with LNS is known. The NINDS supports and conducts
research on genetic disorders such as LNS in an effort to find ways to prevent
and treat these disorders.
Organizations
Purine Research Society
5424 Beech Avenue
Bethesda, MD 20814-1730
purine@erols.com
http://www.purineresearchsociety.org
Tel: 301-530-0354
Fax: 301-564-9597
National Organization for Rare Disorders (NORD)
P.O. Box 1968
(55 Kenosia Avenue)
Danbury, CT 06813-1968
orphan@rarediseases.org
http://www.rarediseases.org
Tel: 203-744-0100 Voice Mail 800-999-NORD (6673)
Fax: 203-798-2291
Source: National Institutes of Health; National Institute of
Neurological Disorders and Stroke
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