hypoxanthine guanine phosphoribosyltransferase partial deficiency (MONDO_0010299, a Monarch Disease Ontology id) can be described as follows. Kelley-Seegmiller syndrome (KSS) is the mildest form of hypoxanthine-guanine phosphoribosyltransferase (HPRT) deficiency, a hereditary disorder of purine metabolism, and is associated with uric acid overproduction (UAO) leading to urolithiasis, and early-onset gout. Also known as: HPRT deficiency, grade I, HPRT partial deficiency, HPRT-related gout, HPRT-related hyperuricemia, HPRT1 partial deficiency, Kelley-Seegmiller syndrome, hyperuricemia, HRPT-related, X-linked recessive, hypoxanthine guanine phosphoribosyltransferase 1 partial deficiency.