Lesch-Nyhan disease (LND) is a rare X-linked inherited neurogenetic disorder of purine metabolism affecting 1 in 380,000 people, and caused by deficiency of the soluble cytoplasmic hypoxanthine-guanine phosphoribosyltransferase (HGprt) enzyme (EC. Here, HPRT1 is linked to Lesch-Nyhan syndrome.