This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
The enzyme deficient is Lesch-Nyhan syndrome is 
Select and explain. 
A. GTRT, B. Glutaminase, C. Transcarboxylase, D. HGPRT
D: HGPRT
Answer: D: HGPRT 
Explanation: Lesch-Nyhan syndrome is due to complete deficiency of hypoxanthine-guanine phosphoribosyl transferase (HGPRT).