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 does Hyperphenylalaninemia mean?
Hyperphenylalaninemia is broadly defined as the presence of blood phenylalanine levels that exceed the limits of the upper reference range (2 mg/dL or 120 µmol/L) without treatment but that are below the level found in patients with phenylketonuria (PKU).
When there is a deficiency of phenylalanine hydroxylase?
Phenylalanine hydroxylase deficiency (PAH deficiency), also called phenylketonuria (PKU), is an inherited disease in which the body cannot properly process the amino acid phenylalanine due to a deficient enzyme called phenylalanine hydroxylase.
What is Hyperphe?
Mild Hyperphe (BPH) is an inherited condition in which a person’s body is unable to properly utilize one part of protein found in food. This condition causes mildly increased levels of phenylalanine in the blood.
What is the life expectancy of a person with phenylketonuria?
PKU does not shorten life expectancy, with or without treatment. Newborn screening for PKU is required in all 50 states. PKU is usually identified by newborn screening. A child’s outlook is very good if she strictly follows the diet.
What causes Hyperphenylalaninemia?
Abnormally high maternal Phe concentrations underlie the clinical effects found in children with this disorder. PKU and hyperphenylalaninemia are caused by mutations in the PAH gene (12q22-q24. 2). Phenylketonuria is transmitted in an autosomal recessive manner.
What causes low phenylalanine?
A defective gene (genetic mutation) causes PKU, which can be mild, moderate or severe. In a person with PKU, this defective gene causes a lack of or deficiency of the enzyme that’s needed to process phenylalanine, an amino acid.
What is normal level of phenylalanine?
Normal levels of phenylalanine in the blood are less than 2 milligrams per deciliter (mg/dL). More than 4 mg/dL of phenylalanine in the blood is considered high and may mean your child has PKU.
Why is PKU testing mandatory?
Although PKU is rare, all newborns in the United States are required to get a PKU test. The test is easy, with virtually no health risk. But it can save a baby from lifelong brain damage and/or other serious health problems. If PKU is found early, following a special, low-protein/low-Phe diet can prevent complications.
What happens when someone with PKU eat protein?
A dangerous buildup of phenylalanine can develop when a person with PKU eats protein-rich foods, such as milk, cheese, nuts or meat, and even grains such as bread and pasta, or eats aspartame, an artificial sweetener. This buildup of phenylalanine results in damage to nerve cells in the brain.
Why does phenylketonuria cause brain damage?
Any amino acids that are not needed are broken down further and removed from the body. People with PKU cannot break down the amino acid phenylalanine, which then builds up in their blood and brain. This can lead to brain damage.
Which is the best treatment for hyperphenylalaninemia?
Hyperphenylalaninemia. Genetic testing and determination of phenylalanine levels in the blood are necessary for diagnosis. Therapy consists of dietary restriction of this amino acid and tetrahydrobiopterin administration.
How does hyperphenylalaninemia affect psychomotor development?
Patients also show increased excretion of 7-biopterin. Affected individuals are asymptomatic and show normal psychomotor development, although transient neurologic deficits in infancy have been reported (Thony et al., 1998).
What are the symptoms of hyperphenylalaninemia ( PKU )?
Eczema PKU-like symptoms include eczema and fair hair and skin coloring. Causes Genetic defects in phenylalanine hydroxylase cause most cases of hyperphenylalaninemia.[emedicine.medscape.com]
What causes hyperphenylalaninemia type IV and V?
Hyperphenylalaninemia types IV and V are due to disorders of tetrahydobiopterin (BH4) metabolism. The patient has features of phenylketonuria (PKU) with low birth weight, extrapyramidal syndrome, and occasional hyperthermia.