Lesch-Nyhan syndrome

Definition:

An inheritable disorder that affects purine metabolism. (Purine metabolism is involved in the body's metabolism of RNA and DNA, the proteins that make up genes and chromosomes.)

Causes, incidence, and risk factors:

Lesch-Nyhan syndrome is inherited as an X-linked trait, therefore the disease is seen only in males. The disease is characterized by increased serum and urine uric acid and by the absence of the enzyme hypoxanthine guanine phosphoribosyltransferase (HGP).

Affected males 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. Children may also develop gout-like swelling in some of their joints