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$Unique_ID{BRK03931}
$Pretitle{}
$Title{Lesch-Nyhan Syndrome}
$Subject{Lesch-Nyhan Syndrome Hereditary Hyperuricemia Hyperuricemia
Choreoathetosis Self-mutilation syndrome Hyperuricemia-Oligophrenia Nyhan
syndrome Juvenile Gout Choreoathetosis Mental Retardation syndrome }
$Volume{}
$Log{}
Copyright (C) 1986, 1990 National Organization for Rare Disorders, Inc.
255:
Lesch-Nyhan Syndrome
** IMPORTANT **
It is possible the main title of the article (Lesch-Nyhan syndrome) is
not the name you expected. Please check the SYNONYMS listing to find the
alternate names and disorder subdivisions covered by this article.
Synonyms
Hereditary Hyperuricemia
Hyperuricemia, Choreoathetosis, Self-mutilation syndrome
Hyperuricemia-Oligophrenia
Nyhan syndrome
Juvenile Gout, Choreoathetosis, Mental Retardation syndrome
General Discussion
** REMINDER **
The information contained in the Rare Disease Database is provided for
educational purposes only. It should not be used for diagnostic or treatment
purposes. If you wish to obtain more information about this disorder, please
contact your personal physician and/or the agencies listed in the "Resources"
section of this report.
Lesch-Nyhan syndrome is a sex-linked hereditary neurological disorder
caused by an enzymatic defect. Onset occurs during infancy and it progresses
to cause aggressive behavior (including self-mutilation) and mental
retardation.
Symptoms
Onset of Lesch-Nyhan syndrome occurs during infancy in males. Babies
affected by the disorder usually appear normal and healthy until they are a
few months old when their condition begins to deteriorate. The defect in the
enzyme that causes Lesch-Nyhan syndrome can be detected with almost 100%
accuracy in people affected by the syndrome and in carriers through a
biochemical study on cultured cells. This defect causes a marked elevation
of uric acid in their blood (hyperuricemia). Affected male babies can be
detected before birth through the same test.
Orange sand (from the urine) in the diaper is usually the first sign of
the disorder. Stones in the urine (urolithiasis) and the appearance of
chalky deposits of sodium urate (tophi) around joints and under the skin
occur as early as age 8 years. As a consequence, kidney disease and
arthritis (gout) may develop. Patients exhibit a startle reaction with
arching of the head and back in response to sudden noise. They suffer from
muscular weakness and perform ceaseless slow writhing movements of the
fingers, arms, toes and face. Speech and swallowing becomes impaired.
Patients vomit frequently.
Most children with the Lesch-Nyhan syndrome are severely underweight,
and many are quite short. In addition, part of the respiratory tract is
constricted and the breath makes a whistling sound (aspiration). Pneumonia
is common in patients with this disorder. A peculiar characteristic of this
syndrome is outbursts of aggressive behavior including self-mutilation. The
children must be protected from themselves.
Causes
Lesch-Nyhan syndrome is an X-linked hereditary disorder caused by a lack of
hypoxanthine-guanine posphoribosyl transferase enzyme which participates in
the metabolism of acid purines. (Human traits including the classic genetic
diseases, are the product of the interaction of two genes for that condition,
one received from the father and one from the mother. X-linked recessive
disorders are conditions which are coded on the X chromosome. Females have
two X chromosomes, but males have one X chromosome and one Y chromosome.
Therefore in females, disease traits on the X chromosome can be masked by the
normal gene on the other X chromosome. Since males have only one X
chromosome, if they inherit a gene for a disease present on the X, it will be
expressed. Men with X-linked disorders transmit the gene to all their
daughters, who are carriers, but never to their sons. Women who are carriers
of an X-linked disorder have a fifty percent risk of transmitting the carrier
condition to their daughters, and a fifty percent risk of transmitting the
disease to their sons.)
People affected with the disorder, or carriers, can be detected through
biochemical studies on cultured cells, even before birth. Female siblings
and maternal aunts can be carriers of the disorder, but usually only males
get Lesch-Nyhan syndrome.
Affected Population
Lesch-Nyhan syndrome affects only males, though females can be genetic
carriers of the disorder.
Therapies: Standard
Allopurinol is used to treat the symptoms related to excessive production of
uric acid in Lesch-Nyhan syndrome. Children with this disorder require
physical restraints such as hip, chest and elbow restraints so they do not
hurt themselves. Elbow restraints keep the hands free. Biting of fingers
and/or lips can be prevented by extracting teeth.
Therapies: Investigational
Investigational studies with a mouse virus are underway. If this virus is
injected into humans, it is hoped that it may trigger production of the
enzyme lacking in patients with Lesch-Nyhan syndrome. This study is in its
initial stages, and it may be some years before the technique moves out of
the laboratory and into clinical trials.
This disease entry is based upon medical information available through
April 1990. Since NORD's resources are limited, it is not possible to keep
every entry in the Rare Disease Database completely current and accurate.
Please check with the agencies listed in the Resources section for the most
current information about this disorder.
Resources
For more information on Lesch-Nyhan Syndrome, please contact:
National Organization for Rare Disorders (NORD)
P.O. Box 8923
New Fairfield, CT 06812-1783
(203) 746-6518
Lesch-Nyhan Syndrome Registry
Dr. Lowell Anderson
New York University School of Medicine
Bellevue Hospital Medical Center
Dept. of Psychiatry
550 First Ave.
New York, NY 10012
(212) 263-6458
NIH/National Institute of Neurological Disorders & Stroke (NINDS)
9000 Rockville Pike
Bethesda, MD 20892
(301) 496-5751
(800) 352-9424
Dr. William L. Nyhan
Professor of Pediatrics
UC School of Medicine, San Diego CA
La Jolla, CA 92093
(619) 534-4150
Research Trust for Metabolic Diseases in Children
Golden Gates Lodge, Weston Rd.
Crewe CW1 1XN, England
Telephone: (0270) 250244
For information on genetics and genetic counseling referrals, please
contact:
March of Dimes Birth Defects Foundation
1275 Mamaroneck Avenue
White Plains, NY 10605
(914) 428-7100
Alliance of Genetic Support Groups
35 Wisconsin Circle, Suite 440
Chevy Chase, MD 20815
(800) 336-GENE
(301) 652-5553
References
Disorders of Purine and Pyrimidine Metabolism: Nyhan, in: Practice of
Pediatrics: Kelley, Harper & Row (1982).