Tetrahydrobiopterin (BH4) has been recently approved as a treatment of patients with phenylketonuria. However, as a confirmation of BH4-responsiveness, it might require a very expensive trial treatment with BH4 or prolonged BH4-loading procedures. The selection of patients eligible for BH4-therapy by means of genotyping of the PAH gene mutations may be recommended as a complementary approach. A...

BACKGROUND Neonatal screening is helpful to prevent serious disability and sufferings caused by congenital or inherited disease. This study was to review the status of neonatal screening for congenital hypothyroidism (CH) and phenylketonuria (PKU) in China. METHODS We analyzed data of neonatal screening for CH and PKU in the past two decades which were obtained from the national network of ne...

OBJECTIVES To compare the neurocognitive outcomes of patients with phenylketonuria (PKU) to determine whether decreasing phenylalanine (Phe) levels to <240 is preferable to the use of 360 μmol/L as an upper-target Phe level. An additional aim was to establish the influence of biochemical indices other than Phe on neurocognitive outcomes. STUDY DESIGN Patients with PKU (n = 63; mean age 10.8 ±...

Phenylketonuria (PKU) is an inborn error in the metabolism of the amino acid phenylalanine (Phe) due to the deficiency of an enzyme phenylalanine hydroxylase (PAH). Current therapy consists of a Phe – restricted diet for life to ensure the healthiest development. It is particularly important for PKU women in the reproductive age group to comply with the diet, since elevated maternal blood Phe l...

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 360-2420 μmol/L), the single dose of 20 mg/kg (Kuvan®) and duration of 24 h was used. RESULTS Among the 4 different catego...

The hepatic phenylalanine hydroxylase system is complex, consisting of at least two enzymes and two non-protein cofactors. In classical phenylketonuria (PKU) the affect component has been shown to be the enzyme, phenylalanine hydroxylase. Recently, several variant forms of PKU have been identified which are due to deficiencies of two of the other components of the hydroxylase system, dihydropte...

UNLABELLED The effect of energy, protein, fat, and phenylalanine on serum phenylalanine concentrations during pregnancy for a set of identical twins with phenylketonuria (PKU) was examined. Blood samples were collected one to two times per week. The subjects completed a 3-d food record prior to each blood collection. The effect of the factors on serum phenylalanine levels was evaluated statisti...

Phenylketonuria (PKU) is caused by deficient activity of the enzyme phenylalanine hydroxylase, needed to convert the essential amino acid (AA) phenylalanine (phe) to tyrosine. In order to prevent neurological damage, lifelong adherence to a low-phe diet that is restricted in natural foods and requires ingestion of a phe-free AA formula to meet protein needs is required. The goal of nutritional ...

The hydroxylase is a trimer of approximately 150 kDa of identical subunits and is located predominantly in the liver. The enzyme has been mapped to human chromosome 12q22-24.1, where the gene comprises 13 exons extending over 90 kb of genomic DNA. Deletions in the gene are not common. A frequent cause among northern Europeans (~40%) is a G-to-A transition at the 5′ donor splice site in intron 1...

We report prenatal diagnosis of phenylketonuria by linkage analysis of the markers linked to the phenylalanine hydroxylase (PAH) gene. Three markers comprising STR (TCTAT)n in intron 3, VNTR (30bp long cassette) in the 3' UTR and Xmn1 RFLP were ascertained in the affected child, the parents and the chorionic villi sample. The foetus was confirmed to be heterozygous for the mutant allele. The di...