What happens to phenylalanine hydroxylase in PKU?
Phenylketonuria (PKU) is an inherited error of metabolism caused by a deficiency in the enzyme phenylalanine hydroxylase. Loss of this enzyme results in mental retardation, organ damage, unusual posture and can, in cases of maternal PKU, severely compromise pregnancy.
Which enzyme is deficient in phenylketonuria?
PKU is characterized by absence or deficiency of an enzyme called phenylalanine hydroxylase (PAH), responsible for processing the amino acid phenylalanine. Amino acids are the chemical building blocks of proteins, and are essential for proper growth and development.
What is the main cause of phenylketonuria?
PKU is caused by mutations in the gene that helps make an enzyme called phenylalanine hydroxylase (pronounced fen-l-AL-uh-neen hahy-DROK-suh-leys), or PAH. This enzyme is needed to convert the amino acid phenylalanine into other substances the body needs.
What is a deficiency of the enzyme 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.
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. PAH deficiency is caused by mutations in the PAH gene.
What does a deficiency in phenylalanine hydroxylase cause?
If individuals with PAH deficiency do not get treatment, phenylalanine can accumulate to harmful levels, which can cause irreversible intellectual disability, seizures, developmental delay, and behavioral problems. PAH deficiency causes a spectrum of disorders ranging from severe to nearly asymptomatic.
What is the expected result of a deficiency in the enzyme phenylalanine hydroxylase?
As Phe is an essential amino acid, having inadequate phenylalanine leads to growth restriction, microcephaly, and developmental problems. The safety of dietary restriction of Phe for individuals with the milder PAH deficiency has not been systematically studied.
What causes phenylalanine hydroxylase deficiency?
How is phenylalanine hydroxylase treated?
The mainstay of treatment for hyperphenylalaninemia involves a low-protein diet and use of a phenylalanine-free medical formula. This treatment must commence as soon as possible after birth and should continue for life. Regular monitoring of plasma phenylalanine and tyrosine concentrations is necessary.