Self-inflicted bites are seen in:

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.