Diseases & Conditions


A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Phenylketonuria


Synonyms of Phenylketonuria
  • Classical Phenylketonuria
  • Hyperphenylalanemia
  • Phenylalanine Hydroxylase Deficiency
  • Phenylalaninemia
  • PKU

Disorder Subdivisions



    General Discussion
    Phenylketonuria (PKU) is an inborn error of metabolism that is detectable during the first days of life with appropriate blood testing (e.g., during routine neonatal screening). PKU is characterized by absence or deficiency of an enzyme (phenylalanine hydroxylase) that is responsible for processing the essential amino acid phenylalanine. (Amino acids, the chemical building blocks of proteins, are essential for proper growth and development.) With normal enzymatic activity, phenylalanine is converted to another amino acid (tyrosine), which is then utilized by the body. However, when the phenylalanine hydroxylase enzyme is absent or deficient, phenylalanine abnormally accumulates in the blood and is toxic to brain tissue.

    Symptoms associated with PKU are typically absent in newborns. Affected infants may be abnormally drowsy and listless (lethargic) and have difficulties feeding. In addition, untreated infants with PKU tend to have unusually light eyes, skin, and hair (light pigmentation) and may develop a rash that appears similar to eczema, an inflammatory skin condition that may be characterized by itching, redness, and blistering in affected areas.

    Without treatment, most infants with PKU develop mental retardation that is typically severe. Those with untreated PKU may also develop additional neurologic symptoms, such as episodes of uncontrolled electrical activity in the brain (seizures), abnormally increased activity (hyperactivity), poor coordination and a clumsy manner of walking (gait), abnormal posturing, aggressive behavior, or psychiatric disturbances. Additional symptoms and findings may include nausea, vomiting, and a musty or mousy body odor due to the presence of a by-product of phenylalanine (phenylacetic acid) in the urine and sweat.

    To prevent mental retardation, treatment consists of a carefully controlled, phenylalanine-restricted diet beginning during the first days or weeks of life. Most experts suggest that a phenylalanine-restricted diet should be lifelong in persons with classical PKU. Classical PKU refers to persons with 2 severe mutations of the phenylalanine hydroxylase gene.
    .

    Organizations related to Phenylketonuria
    • Belgian Association for Metabolic Diseases (BOKS)
      Alice Nahonlann 7
      Melsele None 9120
      Phone #: 323-775-4839
      800 #: N/A
      e-mail: info@boks.be
      Home page: http://www.boks.be
    • Children's PKU Network
      3306 Bumann Rd.
      Encinitas CA 92024
      Phone #: 858-509-0767
      800 #: 800-377-6677
      e-mail: pkunetwork@aol.com
      Home page: http://www.pkunetwork.org/
    • Cochrane Cystic Fibrosis and Genetic Disorders Review Group
      Institute of Child Health
      Liverpool None L12 2 AP
      Phone #: +44- (0-) 1512525696
      800 #: --
      e-mail: cfgd@liv.ac.uk
      Home page: http://www.liv.ac.uk/cfgd/
    • Cook for Love, Inc.
      30 Seneca Street
      Dobbs Ferry NY 10522
      Phone #: 914-674-1025
      800 #: N/A
      e-mail: info@cookforlove.org
      Home page: http://www.cookforlove.org
    • MUMS (Mothers United for Moral Support, Inc) National Parent-to-Parent Network
      150 Custer Court
      Green Bay WI 54301-1243
      Phone #: 920-336-5333
      800 #: 877-336-5333
      e-mail: mums@netnet.net
      Home page: http://www.netnet.net/mums/
    • Madisons Foundation
      PO Box 241956
      Los Angeles CA 90024
      Phone #: 310-264-0826
      800 #: N/A
      e-mail: getinfo@madisonsfoundation.org
      Home page: http://www.madisonsfoundation.org
    • March of Dimes Birth Defects Foundation
      1275 Mamaroneck Avenue
      White Plains NY 10605
      Phone #: 914-428-7100
      800 #: 888-663-4637
      e-mail: Askus@marchofdimes.com
      Home page: http://www.marchofdimes.com
    • Mid-Atlantic Connection for PKU and Allied Disorders, Inc.
      PO Box 6086
      Lancaster PA 17607
      Phone #: 717-872-7546
      800 #: N/A
      e-mail: info@macpad.org
      Home page: http://www.macpad.org
    • NIH/National Institute of Child Health and Human Development
      31 Center Dr
      Bethesda MD 20892
      Phone #: 301-496-5133
      800 #: --
      e-mail: N/A
      Home page: http://www.nichd.nih.gov/
    • National Institute of Mental Retardation
      York University
      Ontario None M3J 1P3
      Phone #: 416-661-9611
      800 #: --
      e-mail: N/A
      Home page: N/A
    • National PKU News
      6869 Woodlawn Avenue NE #116
      Seattle WA 98115-5469
      Phone #: 206-525-8140
      800 #: --
      e-mail: schuett@pkunews.org
      Home page: http://www.pkunews.org
    • Phenylalanine Hydroxylase Locus Knowledgebase (PAHdb)
      McGill Univeristy Health Center
      Monteral, Quebec None H3H 1P3
      Phone #: 514-412-4417
      800 #: --
      e-mail: pahdb@debelle.mcgill.ca
      Home page: http://www.pahde.mcgill.ca



    For a Complete Report

    This is an abstract of a report from the National Organization for Rare Disorders, Inc. ? (NORD). A copy of the complete report can be obtained for a small fee by visiting the NORD website. The complete report contains additional information including symptoms, causes, affected population, related disorders, standard and investigational treatments (if available), and references from medical literature. For a full-text version of this topic, see http://www.rarediseases.org/search/rdblist.html