The molecular basis of phenylalanine hydroxylase deficiency in Croatia

Molecular genetics of tetrahydrobiopterin-responsive phenylalanine hydroxylase deficiency.

Mutations in the phenylalanine hydroxylase (PAH) gene result in phenylketonuria (PKU). Tetrahydrobiopterin (BH(4))-responsive hyperphenylalaninemia has been recently described as a variant of PAH deficiency caused by specific mutations in the PAH gene. It has been suggested that BH(4)-responsiveness may be predicted from the corresponding genotypes. Data from BH(4) loading tests indicated an in...

Wild-type phenylalanine hydroxylase activity is enhanced by tetrahydrobiopterin supplementation in vivo: an implication for therapeutic basis of tetrahydrobiopterin-responsive phenylalanine hydroxylase deficiency.

We previously proposed a novel disease entity, tetrahydrobiopterin (BH4)-responsive phenylalanine hydroxylase (PAH) deficiency, in which administration of BH4 reduced elevated levels of serum phenylalanine [J. Pediatr. 135 (1999) 375-378]. Subsequent reports indicate that the prevalence of BH4-responsive PAH deficiency is much higher than initially anticipated. Although growing attention surrou...

Genotype-predicted tetrahydrobiopterin (BH4)-responsiveness and molecular genetics in Croatian patients with phenylalanine hydroxylase (PAH) deficiency.

Specific mutations in the gene encoding phenylalanine hydroxylase (PAH), located on chromosome 12q22-24.1, are linked to tetrahydrobiopterin (BH4; sapropterin)-responsive phenylketonuria (PKU). Diagnosis is usually done through the newborn screening for PKU, followed by a BH4 loading test. So far, more than 60 mutant alleles, presenting with a substantial residual PAH activity (average approxim...

Tetrahydrobiopterin responsiveness of patients with phenylalanine hydroxylase deficiency.

OBJECTIVE To identify patients responsive to tetrahydrobiopterin (BH4) in a sample of Brazilians with hyperphenylalaninemia due to phenylalanine hydroxylase deficiency (HPA-PAH). METHODS Interventional study, convenience sampling. The inclusion criteria were: diagnosis of HPA-PAH; age ≥ 7 years; phenylalanine-restricted diet and phenylalanine (Phe) levels ≥ 6 mg/dL in all blood tests 1 year b...

Phenylalanine Hydroxylase, Tyrosine Hydroxylase, and Tryptophan Hydroxylase