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: Dental
Self-inﬂicted bites are seen in: 
Select and explain. 
A. Lesch-Nyhan syndrome, B. Friese Maria syndrome, C. Cockayne syndrome, D. Brodie syndrome
A: Lesch-Nyhan syndrome
Answer: A: Lesch-Nyhan syndrome 
Explanation: Lesch-Nyhan syndrome:

Inherited X-linked recessive disorder, affects only males.
Enzyme defect – hypoxanthine guanine phosphoribosyl transferase (HGPRT)
Characterized by excess production of uric acid leading to GOUT.
Self-mutilation – bite their fingers and lips.
Neurological abnormalities like mental – retardation, aggressive behavior, learning disability occur.
Neurological symptoms may be due to dependence of brain on the salvage pathway.
Nephrolithiasis – leads to renal failure.