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. Phenylalanine concentrations ((phe)) 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.
Hyperphenylalaninemia (HPA) and phenylketonuria (PKU) are the result of impaired enzymatic action of phenylalanine-4-hydroxylase (PAH). Underlying the PAH malfunction, however, is an array of direct and indirect mechanisms ultimately linked to tetrahydrobiopterin (BH4) deficiency. BH4 is a cofactor for PAH, tyrosine-3-hydroxylase (TH), and tryptophan-5-hydroxylase (TPH). Impaired hydroxylation.
Define hyperphenylalaninemia. hyperphenylalaninemia synonyms, hyperphenylalaninemia pronunciation, hyperphenylalaninemia translation, English dictionary definition of hyperphenylalaninemia. n. Abbr. PKU A genetic disorder in which the body lacks the enzyme necessary to metabolize phenylalanine to tyrosine. Left untreated, the disorder can cause. Hyperphenylalaninemia - definition of.Hyperphenylalaninemia is a term encompassing various clinical entities that arise due to phenylalanine accumulation. Deficiency of phenylalanine hydroxylase and tetrahydrobiopterin (in a smaller number of cases) due to genetic mutations transferred by an autosomal recessive pattern is the underlying cause. Genetic testing and determination of phenylalanine levels in the blood are necessary for.This article summarizes the present knowledge, recent developments, and common pitfalls in the diagnosis, classification, and genetics of hyperphenylalaninemia, including tetrahydrobiopterin (BH4.
Medical definition of hyperphenylalaninemia: the presence of excess phenylalanine in the blood (as in phenylketonuria).Read More
Hyperphenylalaninemias. Hyperphenylalaninemias are a group of disorders that result in excessive levels of phenylalanine in the blood. The best-known and most common type is phenylketonuria (), which is commonly screened for at birth in the USA and many other developed countries. However, there are various other rare types of non.Read More
Introduction The classification of phenylketonuria and related hyperphenylalaninemias usually includes a variant defined as 'hyperphenylalaninemia with transamination defect' (1-6). Individual cases of this type of metabolic defect are occasionally observed (7-10), and show clinical and biochemical features that are sufficiently similar to justify placing them in a distinct category. It may.Read More
Phenylketonuria (PKU) is the prototype treatable genetic disorder and most advanced countries have been performing newborn screening for more than 40 years. Institution of a low-protein diet early in life can reduce the concentration of phenylalanine in the blood and the brain, and prevent the severe learning and behavioral difficulties that were historically associated with PKU.Read More
Most people with hyperphenylalaninemia have a normal life expectancy. Clinical signs include impaired cognitive function, and behavioral and developmental disorders. In the United States, there are approximately 15-75 cases of hyperphenylalaninemia per 1,000,000 births. Hyperphenylalaninemia occurs in all races and affects both sexes equally.Read More
Today, most neonates are screened for hyperphenylalaninemia, which includes PKU. The incidence of PKU is on average one in 10 000 births. A low-phenylalanine diet introduced within the first weeks of life prevents the symptoms of this disease provided the treatment is well controlled and blood phenylalanine does not exceed normal levels too frequently during the first 8 years of life.Read More
Types of Maternal hyperphenylalaninemia including less common types and symptoms and diagnosis of the correct subtype.Read More
Benign hyperphenylalaninemia (H-PHE) is a mild form of phenylketonuria. It is considered an amino acid condition because people with H-PHE have problems breaking down an amino acid, a building block of proteins, known as phenylalanine. Most people with this condition experience mild symptoms or no symptoms. Condition Type. Amino Acid Disorders. Frequency. The number of people affected with H.Read More
Test description. The Invitae Hyperphenylalaninemia Panel analyzes 6 genes that are known to cause increased plasma phenylalanine levels. Hyperphenylalaninemia is most commonly due to impaired function of phenylalanine hydroxylase (PAH), the enzyme that catabolizes the amino acid phenylalanine to tyrosine, but it can also be due to defects in the regeneration or biosynthesis of the enzyme.Read More
Non-PKU hyperphenylalaninemia, sometimes called benign hyperphenylalaninemia or mild hyperphenylalaninemia, is a mild form of phenylketonuria (PKU), a rare genetic disorder where the body has trouble breaking down a specific protein building block called phenylalanine. People with PKU usually need to limit the amount of phenylalanine in their diet and drink special medical formulas that are.Read More