Lesch-Nyhan syndrome is characterized by

• A. Hyperuricemia, spastic cerebral palsy, mental retardation, and self-mutilation
• B. Hyperimmune deficiency
• C. Self-mutilation with normal uric acid levels
• D. Diabetes insipidus

Answer: (A)

Lesch-Nyhan syndrome comes from a deficiency of HGPRT, the enzyme that salvages purines. When this salvage pathway is defective, purines are broken down into excess uric acid, causing hyperuricemia and related problems like gout and kidney stones. The same enzyme defect also affects brain networks that regulate movement and behavior, leading to severe motor impairment with spasticity and cognitive difficulties, plus a distinctive self-injurious tendency such as biting. The combination of high uric acid and the characteristic neurobehavioral picture is the hallmark of this condition, which is inherited in an X-linked pattern and typically affects males.

Hyperimmune deficiency isn’t part of this syndrome, and describing self-mutilation with normal uric acid would miss the metabolic cause. Diabetes insipidus is unrelated to Lesch-Nyhan.