Strategy for the screening of tetrahydrobiopterin deficiency among hyperphenylalaninaemic patients: 15-years experience.

Tetrahydrobiopterin deficiency in hyperphenylalaninaemic babies has to be rapidly recognized since the disease requires a specific treatment. Based on 15 years experience, we report on the evolution of a strategy for the detection of such patients. A total of 913 hyperphenylalaninaemic patients have been studied and 15 tetrahydrobiopterin deficiencies have been detected or confirmed. DHPR assay in dried blood samples and pteridine measurement in urine collected on filter paper combine convenient sampling and reliable tests for systematic investigation of hyperphenylalaninaemic patients for cofactor deficiency.