title: Genotypic and phenotypic spectrum in attenuated variants of Lesch-Nyhan disease.
abstract: Lesch-Nyhan disease and its attenuated variants are caused by deficiency of the purine salvage enzyme, hypoxanthine-guanine phosphoribosyltransferase (HGprt). All patients exhibit excessive production of uric acid, which increases the risk for nephrolithiasis, renal failure, gouty arthritis and tophi. The mildest phenotype includes only problems related to overproduction of uric acid. The most severe clinical phenotype includes prominent neurological abnormalities and the universal feature is self-injurious behavior. In between the mildest and most severe syndromes is a broad spectrum of phenotypes with varying degrees of neurological, neurocognitive and behavioral abnormalities. The effect of HPRT1 gene mutations on residual HGprt enzyme activity is the most relevant factor contributing to disease phenotype. Attenuated clinical phenotypes are associated with residual enzyme function, whereas the most severe phenotype is usually associated with null activity. In cases of gouty arthritis with urate overproduction, a careful evaluation for motor impairments or neurocognitive abnormalities may help to identify attenuated variants of Lesch-Nyhan disease for better management.
authors.affiliation: Department of Neurology, Emory University, Atlanta, GA, USA.
authors.forename: Rong
authors.initials: R
authors.lastname: Fu
authors.affiliation: Division of Rheumatology, Allergy and Immunology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 83301, Taiwan.
authors.forename: Chung-Jen
authors.initials: CJ
authors.lastname: Chen
authors.affiliation: Department of Neurology, Emory University, Atlanta, GA, USA; Department Human Genetics, Emory University, Atlanta, GA, USA; Department Pediatrics, Emory University, Atlanta, GA, USA. Electronic address: hjinnah@emory.edu.
authors.forename: H A
authors.initials: HA
authors.lastname: Jinnah
mesh_terms: D001519:Behavior; D056726:Genetic Association Studies; D006801:Humans; D007041:Hypoxanthine Phosphoribosyltransferase / Q000172:deficiency; D007926:Lesch-Nyhan Syndrome / Q000175:diagnosis / Q000235:genetics* / Q000473:pathology* / Q000628:therapy; D009154:Mutation / Q000235:genetics*; D014527:Uric Acid / Q000378:metabolism
chemical_list: D014527:Uric Acid; D007041:Hypoxanthine Phosphoribosyltransferase
keywords: Genotype; Lesch–Nyhan disease; Lesch–Nyhan variant; Phenotype