Figure 1From: Long-term follow-up of patients with phenylketonuria treated with tetrahydrobiopterin: a seven years experience Results of the 48 h-BH4 loading test (20 mg/kg/day) of the 19 HPA responder subjects according to their phenotypic class. Cumulative data at each time-point are shown as mean ± SD, except for the 2 cPKU patients where only mean value is represented.Back to article page