Hyperphenylalaninemia is a medical condition characterized by mildly or strongly elevated concentrations of the amino acid phenylalanine in the blood. Phenylketonuria (PKU) can result in severe hyperphenylalaninemia.[2] Phenylalanine concentrations are routinely screened in newborns by the neonatal heel prick (Guthrie test), which takes a few drops of blood from the heel of the infant. Standard phenylalanine concentrations in unaffected persons are about 2-6mg/dl (120–360 μmol/L) phenylalanine concentrations in those with untreated hyperphenylalaninemia can be up to 20 mg/dL (1200 μmol/L). Measurable IQ deficits are often detected as phenylalanine levels approach 10 mg/dL (600 mol/L). Phenylketonuria (PKU)-like symptoms, including more pronounced developmental defects, skin irritation, and vomiting, may appear when phenylalanine levels are near 20 mg/dL (1200 mol/L).[1]Hyperphenylalaninemia is a recessive hereditary metabolic disorder that is caused by the body's failure to convert phenylalanine to tyrosine as a result of the entire or partial absence of the enzyme phenylalanine hydroxylase.[3]
Hyperphenylalaninemia is a medical condition characterized by mildly or strongly elevated concentrations of the amino acid phenylalanine in the blood...
Classical PKU, and its less severe forms "mild PKU" and "mild hyperphenylalaninemia" are caused by a mutated gene for the enzyme phenylalanine hydroxylase...
to 60 μmol/L. A (rare) "variant form" of phenylketonuria called hyperphenylalaninemia is caused by the inability to synthesize a cofactor called tetrahydrobiopterin...
symptoms.[citation needed] Biochemically, patients present with hyperphenylalaninemia, and usually have decreased levels of biopterin and neopterin in...
"Mutation in the 4a-carbinolamine dehydratase gene leads to mild hyperphenylalaninemia with defective cofactor metabolism". American Journal of Human Genetics...
because such drugs would induce the potentially highly dangerous hyperphenylalaninemia or phenylketonuria. Tyrosine hydroxylase inhibitors like metirosine...
the majority of BH4 deficiencies, AD-GTPCHD does not present with hyperphenylalaninemia, and is therefore missed during newborn screening. Furthermore,...
dehydratase deficiency in the body can lead to a less severe condition of hyperphenylalaninemia, which involves an over presence of phenylalanine in the blood....
biosynthesis. Deficiency in PAH activity due to mutations in PAH causes hyperphenylalaninemia (HPA), and when blood phenylalanine levels increase above 20 times...
presents with such symptoms as elevated levels of phenylalanine (hyperphenylalaninemia), microcephaly, hypotonus, mental retardation and epileptic seizures...
neurotransmitters. Biopterin synthesis disorders are also a cause of hyperphenylalaninemia; phenylalanine metabolism requires BH4 as a cofactor. In psychiatry...
deficiency. These may present with malignant phenylketonuria (PKU) and hyperphenylalaninemia (HPA) and lead to a lack of certain neurotransmitters (dopamine...
Phenylketonuria (PKU) Tetrahydrobiopterin (THB, BH4) Mild non-BH4-deficient hyperphenylalaninemia - disorder arising due to mutations of the DNAJC12 gene. Ponzone...
errors of amino acid metabolism Tyrosinemia II Argininemia Benign hyperphenylalaninemia Defects of biopterin cofactor biosynthesis Defects of biopterin...
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