Enzyme deficient in Lesch-Nyhan syndrome?

Ans. D. Hypoxanthine Guanine Phosphoribosyl Transferase. (Ref. Harper 26th/294, Vasudevan pg. 464)Lesch-Nyhan syndrome is defective purine salvage due to absent HGPRT, which converts hypoxanthine to IMP and guanine to GMP. Results in excess uric acid production and de novo purine synthesis. X-linked recessive.Findings: intellectual disability, self-mutilation, aggression, hyperuricemia, gout, dystonia.Treatment: allopurinol or febuxostat (2nd line).HPRTase DEFICIENCY# HGPRTase is predominantly present in liver and involved in purine metabolism# HPRT DEFICIENCY is X-linked recessive.# Affected males are hemizygous for the mutant gene; carrier females are asymptomatic.# A complete deficiency of HPRT, the Lesch-Nyhan syndrome, is characterized by:# Hyperuricemia,0# Self-mutilative behavior,0# Choreoathetosis,# Spasticity, and# Mental retardation.# A partial deficiency of HPRT, the Kelley-Seegmiller syndrome, is associated with:# Hyperuricemia# But no CNS manifestations.# In both disorders, the hyperuricemia results from urate overproduction and can cause uric acid crystalluria, nephrolithiasis, obstructive uropathy, and gouty arthritis.# Early diagnosis and appropriate therapy with allopurinol can prevent or eliminate all the problems attributable to hyperuricemia but have no effect on the behavioral or neurologic abnormalities.