Phenylketonuria: Difference between revisions
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== Phenylketonuria == | |||
[[File:L-Phenylalanin_-_L-Phenylalanine.svg|thumb|right|Chemical structure of L-Phenylalanine]] | |||
'''Phenylketonuria''' ('''PKU''') is a rare [[genetic disorder]] characterized by the inability to metabolize the amino acid [[phenylalanine]]. This condition is caused by a deficiency in the enzyme [[phenylalanine hydroxylase]], which is necessary for converting phenylalanine to [[tyrosine]]. | |||
PKU is | |||
== | == Genetics == | ||
[[File:Autorecessive.svg|thumb|left|Autosomal recessive inheritance pattern]] | |||
PKU is inherited in an [[autosomal recessive]] pattern, meaning that an individual must inherit two copies of the defective gene, one from each parent, to be affected by the disorder. The gene responsible for PKU is located on chromosome 12. | |||
PKU is | |||
== | == Pathophysiology == | ||
In individuals with PKU, the accumulation of phenylalanine in the body can lead to a variety of health problems. High levels of phenylalanine can cause damage to the [[brain]] and [[nervous system]], leading to intellectual disability and other neurological issues. | |||
== | == Clinical Features == | ||
== | [[File:NIH_microcephaly.jpg|thumb|right|Microcephaly is a possible feature of untreated PKU]] | ||
Symptoms of PKU can vary but often include intellectual disability, [[microcephaly]], [[seizures]], and behavioral problems. If untreated, PKU can lead to severe developmental delays and neurological complications. | |||
== Diagnosis == | |||
[[File:Phenylketonuria_testing.jpg|thumb|left|Newborn screening for PKU]] | |||
PKU is typically diagnosed through [[newborn screening]] programs, which test for elevated levels of phenylalanine in the blood. Early detection is crucial for preventing the adverse effects of the disorder. | |||
== Treatment == | |||
The primary treatment for PKU is a [[phenylalanine-restricted diet]], which involves limiting the intake of foods high in phenylalanine, such as meat, dairy, and nuts. Special medical formulas and foods are often used to ensure adequate nutrition while maintaining low phenylalanine levels. | |||
== Complications == | |||
If PKU is not managed properly, individuals may experience severe intellectual disability, behavioral problems, and other neurological issues. Pregnant women with PKU must maintain strict control of their phenylalanine levels to prevent [[maternal PKU syndrome]], which can affect the developing fetus. | |||
== Prevention == | |||
[[File:Phenylalanine_warning_for_phenylketonurics.jpg|thumb|right|Warning label for phenylketonurics]] | |||
Genetic counseling is recommended for families with a history of PKU. Prenatal testing and carrier screening can help identify at-risk pregnancies and individuals. | |||
== Related Pages == | |||
* [[Inborn errors of metabolism]] | |||
* [[Amino acid metabolism]] | |||
* [[Genetic disorders]] | |||
[[File:Inborn_errors_of_metabolism_of_phenylalanine_and_tyrosine.svg|thumb|left|Metabolic pathway of phenylalanine and tyrosine]] | |||
== See Also == | |||
* [[Tyrosinemia]] | |||
* [[Alkaptonuria]] | |||
* [[Maple syrup urine disease]] | |||
{{Medical resources}} | |||
[[Category:Genetic disorders]] | [[Category:Genetic disorders]] | ||
[[Category:Metabolic disorders]] | [[Category:Metabolic disorders]] | ||
[[Category: | [[Category:Autosomal recessive disorders]] | ||
Revision as of 14:23, 21 February 2025
Phenylketonuria

Phenylketonuria (PKU) is a rare genetic disorder characterized by the inability to metabolize the amino acid phenylalanine. This condition is caused by a deficiency in the enzyme phenylalanine hydroxylase, which is necessary for converting phenylalanine to tyrosine.
Genetics

PKU is inherited in an autosomal recessive pattern, meaning that an individual must inherit two copies of the defective gene, one from each parent, to be affected by the disorder. The gene responsible for PKU is located on chromosome 12.
Pathophysiology
In individuals with PKU, the accumulation of phenylalanine in the body can lead to a variety of health problems. High levels of phenylalanine can cause damage to the brain and nervous system, leading to intellectual disability and other neurological issues.
Clinical Features

Symptoms of PKU can vary but often include intellectual disability, microcephaly, seizures, and behavioral problems. If untreated, PKU can lead to severe developmental delays and neurological complications.
Diagnosis
PKU is typically diagnosed through newborn screening programs, which test for elevated levels of phenylalanine in the blood. Early detection is crucial for preventing the adverse effects of the disorder.
Treatment
The primary treatment for PKU is a phenylalanine-restricted diet, which involves limiting the intake of foods high in phenylalanine, such as meat, dairy, and nuts. Special medical formulas and foods are often used to ensure adequate nutrition while maintaining low phenylalanine levels.
Complications
If PKU is not managed properly, individuals may experience severe intellectual disability, behavioral problems, and other neurological issues. Pregnant women with PKU must maintain strict control of their phenylalanine levels to prevent maternal PKU syndrome, which can affect the developing fetus.
Prevention
Genetic counseling is recommended for families with a history of PKU. Prenatal testing and carrier screening can help identify at-risk pregnancies and individuals.