Lesch-Nyhan syndrome (LNS) is the most severe form of hypoxanthine-guanine phosphoribosyltransferase (HPRT) deficiency, a hereditary disorder of purine metabolism, and is associated with uric acid overproduction (UAO), neurological troubles, and behavioral problems. The disease is Lesch-Nyhan syndrome (Monarch Disease Ontology id MONDO_0010298). Also known as: HG-PRT deficiency, HPRT complete deficiency, HPRT deficiency grade IV, Lesch - Nyhan syndrome, Lesch Nyhan Syndrome, Lesch-Nyhan syndrome, X-linked recessive, X-linked hyperuricemia, X-linked hyperuricemia (disorder) [ambiguous].