ICD-11 definition : Hypoxanthine-guanine phosphoribosyltransferase (HPRT) deficiency is a hereditary disorder
of purine metabolism associated with uric acid overproduction and a continuum spectrum
of neurological manifestations depending on the degree of the enzyme deficiency. Two
forms of the disease have been described: LNS, the most severe form, with a complete
enzyme deficiency, and Lesch-Nyhan variants with partial HPRT deficiency (Kelley-Seegmiller
syndrome).;
Hypoxanthine-guanine phosphoribosyltransferase (HPRT) deficiency is a hereditary disorder
of purine metabolism associated with uric acid overproduction and a continuum spectrum
of neurological manifestations depending on the degree of the enzyme deficiency. Two
forms of the disease have been described: LNS, the most severe form, with a complete
enzyme deficiency, and Lesch-Nyhan variants with partial HPRT deficiency (Kelley-Seegmiller
syndrome).