What physical sign may indicate Lesch-Nyhan syndrome?

Lesch-Nyhan syndrome is a rare genetic disorder caused by a deficiency of the enzyme hypoxanthine-guanine phosphoribosyltransferase (HPRT). This condition is characterized by a triad of symptoms: uric acid overproduction leading to gout, neurological and behavioral disturbances, and self-injurious behaviors.

The presence of self-injurious behavior in individuals with Lesch-Nyhan syndrome is particularly significant as it sets this condition apart from other disorders. Patients may bite themselves, often resulting in serious injury, and exhibit compulsive behaviors. This behavior is thought to arise from dysfunctions within certain brain pathways, particularly those associated with motor control and impulse regulation.

While other signs such as hypotonia (reduced muscle tone), chorea (involuntary dance-like movements), or features of muscular dystrophy may occur in various neurological conditions, they are not hallmarks of Lesch-Nyhan syndrome. The distinctive combination of symptoms and, most importantly, the self-injurious behavior are crucial for diagnosing this specific condition.