Lesch-Nyhan syndrome is an inheritable disorder that affects how the body builds and breaks down purines. Purines are units in RNA and DNA, which make up the body's genetic blueprint.

Lesch-Nyhan syndrome is inherited as an X-linked trait. Therefore, the disease is seen mainly in males. It is characterized by increased blood and uric acid levels and by the absence of the enzyme hypoxanthine guanine phosphoribosyltransferase (HGP).

Males with Lesch-Nyhan have delayed motor development followed by bizarre, sinuous movements and increased deep tendon reflexes. A striking feature of Lesch-Nyhan syndrome is self-destructive behavior characterized by chewing off fingertips and lips, if not restrained.

The excess uric acid levels cause children to develop gout-like swelling in some of their joints. In some cases, renal dysfunction develops because of the excess uric acid levels.

• Family history of Lesch-Nyhan syndrome
• Male infant with delayed motor development
• Movement disorder
• Destructive chewing of fingers or lips (self-destructive behavior)

A physical examination may show:

• Hyperreflexia
• Spasticity
• Choreoathetoid movements
• Compulsive self-destructive behavior
• Increased serum uric acid
• Increase excretion of uric acid, urine
• Decreased HGP levels in cultured fibroblasts

• Serum chemistry, uric acid
• Urine chemistry, uric acid
• Skin biopsy tissue culture (fibroblasts)