Lesch-Nyhan syndrome: a case report.

Lesch-Nyhan syndrome (LNS) is a rare X-linked recessive disorder caused by a mutation in the hypoxanthine phosphoribosyltransferase 1 (HPRT1) gene. This syndrome is characterized by excessive production of uric acid, mental retardation, self-mutilation, choreoathetosis, and spasticity. The most distinctive symptom is compulsive self-mutilation. For patients with LNS, different methods have been tried to reduce self-biting behaviors including restraints, behavioral treatment, medications, deep brain stimulation, tooth extraction and botulinum toxin A injection. In this report, we present a case of LNS undergoing cheiloplasty due to self-mutilation and tooth extraction of the left deciduous maxillary canine.