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

Maple Syrup Urine Disease


Synonyms of Maple Syrup Urine Disease
  • BCKD Deficiency
  • Branched Chain Alpha-Ketoacid Dehydrogenase Deficiency
  • Branched Chain Ketonuria I
  • Classical Maple Syrup Urine Disease
  • MSUD

Disorder Subdivisions

  • Classic Maple Syrup Urine Disease
  • Intermediate Maple Syrup Urine Disease
  • Intermittent Maple Syrup Urine Disease
  • Thiamine-Responsive Maple Syrup Urine Disease


General Discussion
Maple syrup urine disease (MSUD) is a rare genetic disorder characterized by deficiency of certain enzymes (branched-chain alpha-keto acid dehydrogenase complex) required to breakdown (metabolize) specific amino acids in the body. Because these amino acids are not metabolized, they, along with their various byproducts, abnormally accumulate in the cells and fluids of the body. Such accumulation can cause a variety of symptoms including lethargy, irritability, poor feeding, abnormal movements and a characteristic odor of maple syrup in the earwax (cerumen), sweat and urine of affected individuals. In addition, if untreated various neurological complications including seizures, coma and brain damage may occur. Failure to promptly detect and treat MSUD can lead to life-threatening complications. However, the disorder can be successfully managed through a specialized diet. Even with treatment affected individuals remain at risk for developing episodes of acute illness (metabolic crisis) often triggered by infection, injury, failure to eat (fasting) or psychological stress. During these episodes there is a rapid, sudden spike in amino acid levels necessitating immediate medical intervention.

At least four subtypes of MSUD have been identified in the medical literature. Some researchers include a fifth subtype, although other researchers consider this a separate distinct disorder. The various subtypes of MSUD have different levels of residual enzyme activity, different severity, and different ages of onset. All forms are inherited as autosomal recessive traits.

Organizations related to Maple Syrup Urine Disease
  • 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
  • CLIMB (Children Living with Inherited Metabolic Diseases)
    Climb Building
    Crewe Intl CW2 6BG
    Phone #: +44- 87-0 7700 325
    800 #: --
    e-mail: info@climb.org.uk
    Home page: http://www.CLIMB.org.uk
  • 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
  • Maple Syrup Urine Disease Family Support Group
    82 Ravine Road
    Powell OH 43065
    Phone #: 740-548-4475
    800 #: --
    e-mail: dbulcher@aol.com
    Home page: http://www.msud-support.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
  • NIH/National Digestive Diseases Information Clearinghouse
    2 Information Way
    Bethesda MD 20892-3570
    Phone #: 301-654-3810
    800 #: 800-891-5389
    e-mail: nddic@info.niddk.nih.gov
    Home page: http://www.niddk.nih.gov
  • The Arc (a national organization on mental retardation)
    1010 Wayne Ave
    Silver Spring MD 20910
    Phone #: 301-565-3842
    800 #: 800-433-5255
    e-mail: info@thearc.org
    Home page: http://www.thearc.org/



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