Background: Lesch-Nyhan disease is a rare X-linked neurodevelopemental metabolic disorder caused by a wide
variety of mutations in the HPRT1 gene leading to a deficiency of the purine recycling enzyme hypoxanthine-guanine
phosphoribosyltransferase (HGprt). The residual HGprt activity correlates with the various phenotypes of Lesch-Nyhan
(LN) patients and in particular with the different degree of neurobehavioral disturbances. The prevalence of this
disease is considered to be underestimated due to large heterogeneity of its clinical symptoms and the difficulty of
diagnosing of the less severe forms of the disease. We therefore searched for metabolic changes that would facilitate
an early diagnosis and give potential clues on the disease pathogenesis and potential therapeutic approaches