Lesch-Nyhan Disease and Related Disorders of Purine Metabolism

Lesch-Nyhan disease is the most severe or complete phenotype of deficiency in hypoxanthine-guanine phosphoribosyl transferase (HPRT). Other variant enzymes are found in patients without abnormality in behavior or mental development; and there are intermediate phenotypes in which enzyme activity is intermediate. A considerable number and variety of mutations in the HPRT gene have been discovered.