What is mild Hyperphenylalaninemia?
What is mild Hyperphenylalaninemia?
Disease definition. A rare form of phenylketonuria, an inborn error of amino acid metabolism, characterized by blood phenylalanine (Phe) concentrations of 120-600 micromol/L with or without clinical manifestations of impaired cognitive function, and behavioral and developmental disorders.
What causes Hyperphenylalaninemia?
Hyperphenylalaninemia is a recessive inherited metabolic condition, caused by the inability of the body to convert phenylalanine (Phe) to tyrosine, due to the total or partial absence of the enzyme phenylalanine hydroxylase. Phenylalanine is an essential amino acid found in protein-rich foods.
What is Sapropterin used for?
Sapropterin is used to lower phenylalanine levels in the blood of patients with phenylketonuria (PKU). High levels of phenylalanine (an amino acid) in the blood can cause severe brain damage, including severe mental retardation, seizures, tremors, or decreased learning ability.
How common is Hyperphenylalaninemia?
EPIDEMIOLOGY AND RISK FACTORS. Hyperphenylalaninemia due to BH4 deficiency is rare and accounts for 2% of all PKU cases.
How is Hyperphenylalaninemia diagnosed?
Hyperphenylalaninemia most is commonly diagnosed by newborn screening and must be distinguished from classic PKU by confirmatory testing at an experienced center. Some cases in adult women have been detected using maternal screening programs or following birth of children with birth defects.
How is Hyperphenylalaninemia inherited?
To learn more about genetic conditions, visit MedlinePlus Genetics. Non-PKU hyperphenylalaninemia is an autosomal recessive condition. Babies inherit it when each parent passes down a nonworking PAH gene to their baby. Only babies with two nonworking PAH genes—one from the mom and one from the dad—have this condition.
Is sapropterin a drug?
Sapropterin is in a class of medications called cofactors. It works by helping the body to break down phenylalanine so it will not build up in the blood.
Is there a generic for Kuvan?
Par’s sapropterin dihydrochloride tablets and powder for oral solution are the generic version of Kuvan® tablets and powder for oral solution and are the first, and currently the only, generic versions available.
How is Hyperphenylalaninemia treated?
Hyperphenylalaninemia may be corrected using a low phenylalanine diet or, in deficiencies of GTP cyclohydrolase, 6PTPS and pterin 4α-carbinolamine, by administration of oral BH4 (0.5–40 mg/d). BH4 is usually ineffective in DHPR deficiency.
What does too much phenylalanine do to the body?
Phenylalanine can cause intellectual disabilities, brain damage, seizures and other problems in people with PKU . Phenylalanine occurs naturally in many protein-rich foods, such as milk, eggs and meat. Phenylalanine is also sold as a dietary supplement.
How is hyperphenylalaninemia corrected?
Hyperphenylalaninemia may be corrected using a low phenylalanine diet or, in deficiencies of GTP cyclohydrolase, 6PTPS and pterin 4α-carbinolamine, by administration of oral BH4 (0.5–40 mg/d). BH4 is usually ineffective in DHPR deficiency.
What is the Recommended Dietary treatment for phenylalanine levels?
Practices of dietary treatment vary in children with phenylalanine levels in the intermediate range of 7-11 mg/dL (425-660 µmol/L). Most centers in the United States recommend restricting dietary phenylalanine when levels exceed 10 mg/dL (600 µmol/L). Some also recommend treatment for levels that exceed 8-9 mg/dL (480-545 µmol/L).
What is the treatment for hyperphenylalaninemia BH4 deficiency?
Therapy for the hyperphenylalaninemia BH4 defects includes a low-phenylalanine diet, correction of central monoamine deficits, and prevention of folate deficiency. Oral BH4 (5 mg/kg) will correct the peripheral metabolism of phenylalanine when the defect is not due to a DHPR deficiency.
How does hyperphenylalaninemia cause encephalopathy?
Hyperphenylalaninemia causes a neonatal-onset chronic encephalopathy as a result of defects in phenylalanine metabolism, including phenylalanine hydroxylase (PAH) deficiency, tetrahydrobiopterin (BH4) synthesis deficiency, and GTP cyclohydrolase (GTPC) deficiency.
