Medical Dictionary

Lesch–Nyhan syndrome

noun Lesch–Ny·han syndrome \ˈlesh-ˈnī-ən-\

Medical Definition of Lesch–Nyhan syndrome

  1. :  a rare and usually fatal genetic disorder of male children that is inherited as an X-linked recessive trait and is characterized by hyperuricemia, mental retardation, spasticity, compulsive biting of the lips and fingers, and a deficiency of hypoxanthine-guanine phosphoribosyltransferase—called also Lesch-Nyhan disease

Biographical Note for lesch–nyhan syndrome




(1939–2008), and



William Leo

(born 1926), American pediatricians. Nyhan held the position of professor of pediatrics at several medical schools, including Johns Hopkins. He had a major interest in the disorders of amino acid metabolism and routinely analyzed blood and urine for amino acids. The urine of a pair of patients, two brothers, was found to contain urate crystals. In addition, the brothers were suffering from an obvious but unknown neurological disorder. Nyhan, aided by Lesch, a student research assistant, began investigating urate metabolism and the characteristics of the previously unrecognized genetic disorder exhibited by their two cases. Lesch published a description of the Lesch-Nyhan syndrome in 1964. This report laid the groundwork for the discovery in 1967 of the absence of hypoxanthine-guanine phosphoribosyltransferase in children affected with the syndrome.

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feeling or affected by lethargy

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