Nephrocalcinosis and Renal Failure in Lesch-Nyhan Syndrome: Report of Two Familial Cases and Review of the Literature.

Lesch-Nyhan syndrome is an X-linked recessive inborn error of purine metabolism, due to deficiency of the enzyme HPRT (hypoxanthine-guanine phosphoribosyl transferase) and underlying HPRT gene mutations (over 300 mutations identified up to date). It is characterized by a wide range of neurological symptoms and signs (mainly a combination of spastic diplegia with choreoathetosis and an overall psychomotor redardation). Herein, we report of two cousins with Lesch-Nyhan syndrome and a confirmed novel HPRT gene mutation: c.65T>C, who both developed nephrocalcinosis and renal failure, findings not been previously published in children with HPRT deficiency.