Premium
Long‐term follow‐up of patients with phenylketonuria receiving tetrahydrobiopterin treatment
Author(s) -
Trefz Friedrich K.,
Scheible D.,
FrauendienstEgger G.
Publication year - 2010
Publication title -
journal of inherited metabolic disease
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.462
H-Index - 102
eISSN - 1573-2665
pISSN - 0141-8955
DOI - 10.1007/s10545-010-9058-x
Subject(s) - tetrahydrobiopterin , phenylalanine hydroxylase , phenylalanine , medicine , hyperphenylalaninemia , endocrinology , phenylketonurias , anabolism , catabolism , chemistry , metabolism , amino acid , biochemistry , nitric oxide synthase , nitric oxide
Treatment with tetrahydrobiopterin (BH 4 ), the natural cofactor of phenylalanine hydroxylase (PAH), can reduce blood phenylalanine (Phe) levels in patients with BH 4 ‐responsive phenylketonuria (PKU). A number of studies has reported on the short‐term BH 4 treatment of patients with PKU, but long‐term data are lacking. Here, we describe the effects of long‐term treatment with BH 4 on 16 patients, who showed a >28% reduction in blood Phe following testing for BH 4 overload. The mean dose of BH 4 was 16 mg/kg body weight (range 5–36 mg/kg body weight). The mean treatment duration was 56 months (range 24–110 months). Of 16 patients, 14 achieved long‐term Phe control with BH 4 treatment, with a mean blood Phe concentration of 321 ± 236 µmol/l. The mean decrease from baseline in blood Phe levels in these 14 patients was 54.6%. Of the seven patients who required continued dietary restriction, Phe intake increased from 200–300 mg/day to 800–1000 mg/day. Factors that may cause fluctuation of Phe levels in BH 4 ‐treated patients include patients’ PAH genotype, Phe intake, changes in protein catabolism or anabolism, and periods of illness or infection.