DIAGNOSISThe diagnosis of Lesch-Nyhan syndrome may be confirmed by a thorough clinical evaluation, including a detailed patient history and specialized blood tests. Children with this disorder have abnormally high concentrations of uric acid in the blood. The absence of the HPRT enzyme in cells from any tissue confirms the diagnosis. Molecular genetic testing for the HPRT1 gene is available to determine the specific disease-causing mutation. Carrier testing for Lesch-Nyhan syndrome is possible using molecular genetic testing.Prenatal diagnosis and preimplantation genetic diagnosis are possible if the disease-causing HPRT1 gene mutation has been identified in an affected family member. Prenatal diagnosis can also be done by enzyme analysis.