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PhenylketonuriaAka: PKU

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  1. See Also
    1. Inborn Errors of Metabolism
  2. Epidemiology
    1. Incidence: 1:15000
  3. Pathophysiology
    1. Autosomal-recessive disorder
    2. Phenylalanine hydroxylase gene mutation
      1. Enzyme converts phenylalanine to tyrosine
      2. Phenylalanine concentrations rise with mutation
    3. Phenylalanine threshold for adverse effects >20 mg/dl
  4. Symptoms
    1. Irritability
  5. Signs: Complications on unrestricted diet
    1. Head Circumference small for age (Microcephaly)
    2. Cognitive delay
    3. Light skin pigmention
  6. Labs
    1. Identified on Newborn Screen
  7. Management
    1. Strict low phenylalanine diet for life
      1. Infant: Low Phenylalanine formula
      2. Pregnancy: Monitor phenylalanine concentrations
    2. Supplementation
      1. Tyrosine 25 mg/kg/day
      2. Amino acid dosing
        1. Infant: 3 g/kg/day
        2. Child: 2 g/kg/day
  8. References
    1. Raghuveer (2006) Am Fam Physician 73:1981

Phenylketonurias (C0031485)

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.
ConceptsDisease or Syndrome (T047)
ICD9270.1
EnglishPHENYLALANINEMIA, Phenylketonuria, Phenylketonurias, PHENYLKETOURIA, PKU
CreditsDerived from the NIH UMLS (Unified Medical Language System)



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