II. Epidemiology
- Incidence: 1:15000
III. Pathophysiology
- Autosomal-recessive disorder
-
Phenylalanine hydroxylase gene mutation
- Enzyme converts Phenylalanine to Tyrosine
- Phenylalanine concentrations rise with mutation
- Phenylalanine threshold for adverse effects >20 mg/dl
IV. Symptoms
- Irritability
V. Signs: Complications on unrestricted diet
- Head Circumference small for age (Microcephaly)
- Cognitive delay
- Light skin pigmention
VI. Labs
- Identified on Newborn Screen
VII. Management
- Strict low Phenylalanine diet for life
- Infant: Low Phenylalanine formula
- Pregnancy: Monitor Phenylalanine concentrations
- Supplementation
- Tyrosine 25 mg/kg/day
- Amino Acid dosing
- Infant: 3 g/kg/day
- Child: 2 g/kg/day
VIII. References
Images: Related links to external sites (from Bing)
Related Studies
Definition (CHV) | A genetic disorder in which the body lacks the enzyme necessary to metabolize phenylalanine |
Definition (CHV) | A genetic disorder in which the body lacks the enzyme necessary to metabolize phenylalanine |
Definition (CHV) | A genetic disorder in which the body lacks the enzyme necessary to metabolize phenylalanine |
Definition (CHV) | A genetic disorder in which the body lacks the enzyme necessary to metabolize phenylalanine |
Definition (CHV) | A genetic disorder in which the body lacks the enzyme necessary to metabolize phenylalanine |
Definition (CHV) | A genetic disorder in which the body lacks the enzyme necessary to metabolize phenylalanine |
Definition (CHV) | A genetic disorder in which the body lacks the enzyme necessary to metabolize phenylalanine |
Definition (MEDLINEPLUS) |
Phenylketonuria (PKU) is a genetic disorder in which the body can't process part of a protein called phenylalanine (Phe). Phe is in almost all foods. If the Phe level gets too high, it can damage the brain and cause severe intellectual disability. All babies born in U.S. hospitals must now have a screening test for PKU. This makes it easier to diagnose and treat the problem early. The best treatment for PKU is a diet of low-protein foods. There are special formulas for newborns. For older children and adults, the diet includes many fruits and vegetables. It also includes some low-protein breads, pastas and cereals. Nutritional formulas provide the vitamins and minerals they can't get from their food. Babies who get on this special diet soon after they are born develop normally. Many have no symptoms of PKU. It is important that they stay on the diet for the rest of their lives. NIH: National Institute of Child Health and Human Development |
Definition (NCI_NCI-GLOSS) | An inherited disorder that causes a build-up of phenylalanine (an amino acid) in the blood. This can cause mental retardation, behavioral and movement problems, seizures, and delayed development. Using a blood test, PKU can easily be found in newborns, and treatment is a diet low in phenylalanine. |
Definition (NCI) | A disorder characterized by the body's inability to break down and utilize the essential amino acid phenylalanine. |
Definition (MSH) | A group of autosomal recessive disorders marked by a deficiency of the hepatic enzyme PHENYLALANINE HYDROXYLASE or less frequently by reduced activity of DIHYDROPTERIDINE REDUCTASE (i.e., atypical phenylketonuria). Classical phenylketonuria is caused by a severe deficiency of phenylalanine hydroxylase and presents in infancy with developmental delay; SEIZURES; skin HYPOPIGMENTATION; ECZEMA; and demyelination in the central nervous system. (From Adams et al., Principles of Neurology, 6th ed, p952). |
Definition (CSP) | group of autosomal recessive disorders marked by a deficiency of the hepatic enzyme phenylaline hydroxylase or less frequently by reduced activity of dihydropteridine reductase. |
Concepts | Disease or Syndrome (T047) |
MSH | D010661 |
ICD9 | 270.1 |
SnomedCT | 154735006, 190687004 |
LNC | LP56980-3, LA12520-5, LA21169-0 |
English | Phenylketonuria, Phenylketonuria (PKU), PHENYLKETONURIA, PKU, PKU - Phenylketonuria, phenylalaninemia, phenylketonuria (diagnosis), phenylketonuria, Phenylalaninemia, Phenylketouria, Phenylketonuria - pku, Phenylketonurias [Disease/Finding], phenylketonurias, phenylketonuria (PKU), phenylketouria, pku phenylketonuria, Phenylketonuria (disorder), Classical Phenylketonuria, Phenylalaninaemia, Phenylketonurias, PKU (Hereditary Disorder), Phenylketonuria [PKU] |
French | PHENYLCETONURIE, Phénylalaninémie, Phénylkétonurie (PKU), PKU, Phénylcétonuries, Phénylcétonurie |
Portuguese | FENILCETONURIA, Fenilalaninemia, Fenilcetonúria, Fenilcetonúrias |
Spanish | FENILCETONURIA, Fenilalaninemia, PKU, Fenilcetonuria (FCU), Fenilcetonuria, Fenilcetonurias |
German | PHENYLKETONURIE, Phenylketonurie (PKU), Phenylalaninaemie, PKU, Phenylketonurie |
Italian | Fenilchetonuria, Fenilalaninemia, Fenilchetonuria (PKU), PKU, Fenilchetonurie |
Dutch | FKU, fenylalaninemie, fenylketonurie (FKU), fenylketonurie, Fenylketonurie, Ketonurie, fenyl-, Fenylketonurieën, Ketonurieën, fenyl- |
Japanese | フェニルアラニン血症, フェニルアラニンケツショウ, フェニルアラニンケッショウ, フェニルケトンニョウショウ, フェーリング病, フェニル焦性ブドウ酸性白痴, フォリング症候群, フォリング病, Folling病, フェニルアラニンヒドロキシラーゼ欠損症, フェニルケトン尿, フェニルピルビン酸性白痴, フェニルケトン尿症, Folling症候群 |
Swedish | Fenylketonuri |
Czech | fenylketonurie, Fenylalaninemie, PKU, Fenylketonurie (PKU), Fenylketonurie |
Finnish | Klassinen fenylketonuria |
Russian | FENILKETONURII, ФЕНИЛКЕТОНУРИИ |
Croatian | FENILKETONURIJE |
Polish | Fenyloketonuria |
Hungarian | Phenylalaninaemia, Phenylketonuria (phenylketonuria), Phenylalaninemia, Phenylketonuria, Phenylketouria |
Norwegian | Phenylketonuri, PKU, Fenylketonuri |