INFORMATION ON CHOREOACANTHOCYTOSIS

Choreoacanthocytosis (Lesch-Nyhan) syndrome is a rare genetic disorder that affects males. Males with this syndrome develop physical handicaps, mental retardation, and kidney problems. It is caused by the full absence of a particular enzyme. Self injury is a classic feature of this genetic disease.

CAUSES OF CHOREOACANTHOCYTOSIS

The syndrome is caused by a severe change (mutation) in the HPRT gene. Since the HPRT gene is situated on the X chromosome, Lesch-Nyhan syndrome is considered an X-linked disorder and therefore only affects males.

The HPRT gene is responsible for the production of the enzyme called hypoxanthine-guanine phosphoribosyltransferase (HPRT). HPRT catalyzes a reaction that is necessary to prevent the buildup of uric acid. A severe mutation in the HPRT gene leads to an absence of HPRT enzyme activity which, in turn, leads to markedly elevated uric acid levels in the blood (hyperuricemia). This buildup of uric acid is toxic to the body and is linked to the symptoms associated with the disease. Absence of the HPRT enzyme activity is also thought to change the chemistry of certain parts of the brain, such as the basal ganglia, affecting neurotransmitters (chemicals used for communication between nerve cells),

SYMPTOMS OF CHOREOACANTHOCYTOSIS

At birth, males with Lesch-Nyhan syndrome appear entirely normal. Development is generally normal for the first few months. Symptoms develop between three to six months of age. Sand-like crystals of uric acid in the diapers may be one of the first symptoms of the disease. The baby may be curiously irritable. normally, the first sign of nervous system impairment is the inability to lift their head or sit up at an appropriate age. Many patients with Lesch-Nyhan will never learn to walk. By the end of the first year, writhing motions (athetosis), and spasmodic movements of the limbs and facial muscles (chorea) are clear proof of defective motor development.

The compulsive self-injury connected with Lesch-Nyhan syndrome begins, on average, at three years. The self-injury begins with biting of the lips and tongue. As the disease progresses, affected individuals frequently develop finger biting and head banging. The self-injury can increase during times of stress.

Males with Lesch-Nyhan disease may also develop kidney damage due to kidney stones. Swollen and tender joints (gout) are another common problem. Acids, and other chemicals. This change in the nervous system is also related to the symptoms connected with Lesch-Nyhan syndrome.

TREATMENT OF CHOREOACANTHOCYTOSIS

There are no known treatments for the neurological defects of Lesch-Nyhan. The medication Allopurinol can lower blood uric acid levels. This medication does not correct many of the symptoms. Some patients with Lesch-Nyhan syndrome have their teeth removed to prevent self-injury. Restraints are recommended to decrease self-destructive behaviors.