Tetrahydrobiopterin responsiveness in a series of 53 cases of phenylketonuria and hyperphenylalaninemia in Iran

To determine the prevalence of 6R-Tetrahydrobiopterin (BH4) responsive phenylketonuria (PKU) in 53 cases of patients with various classification of hyperphenylalaninemia and PKU Excluding the BH4 deficient type referring to children's medical center in Iran (phenylalanine 360–2420μmol/L), the single dose of 20mg/kg (Kuvan®) and duration of 24h was used.