Maple Syrup Urine Disease
National Organization for Rare Disorders, Inc.
It is possible that the main title of the report Maple Syrup Urine Disease is not the name you expected. Please check the synonyms listing to find the alternate name(s) and disorder subdivision(s) covered by this report.
- BCKD Deficiency
- Branched Chain Alpha-Ketoacid Dehydrogenase Deficiency
- Branched Chain Ketonuria I
- Classical Maple Syrup Urine Disease
- Intermittent Maple Syrup Urine Disease
- Intermediate Maple Syrup Urine Disease
- Thiamine-Responsive Maple Syrup Urine Disease
- Classic Maple Syrup Urine Disease
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.
Children Living with Inherited Metabolic Diseases (CLIMB)
176 Nantwich Road
Crewe, Intl CW2 6BG
Tel: 0845 241 2174
Tel: 800 652 3181
March of Dimes Birth Defects Foundation
1275 Mamaroneck Avenue
White Plains, NY 10605
1660 L Street, NW, Suite 301
Washington, DC 20036
NIH/National Institute of Diabetes, Digestive & Kidney Diseases
Office of Communications & Public Liaison
Bldg 31, Rm 9A06
31 Center Drive, MSC 2560
Bethesda, MD 20892-2560
Maple Syrup Urine Disease Family Support Group
9517 Big Bear Ave
Powell, OH 43065
MUMS National Parent-to-Parent Network
150 Custer Court
Green Bay, WI 54301-1243
Belgian Association for Metabolic Diseases
Alice Nahonlann 7
Tel: 0498 701 503
Fax: 03 775 48 39
Genetic and Rare Diseases (GARD) Information Center
PO Box 8126
Gaithersburg, MD 20898-8126
PO Box 241956
Los Angeles, CA 90024
Cook for Love, Inc.
30 Seneca Street
Dobbs Ferry, NY 10522
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This is an abstract of a report from the National Organization for Rare Disorders (NORD). A copy of the complete report can be downloaded free from the NORD website for registered users. The complete report contains additional information including symptoms, causes, affected population, related disorders, standard and investigational therapies (if available), and references from medical literature. For a full-text version of this topic, go to MyD-H, the Dartmouth-Hitchcock patient portal. You must be a registered MyD-H user for the Lebanon, Manchester, or Nashua locations to access this site.
The information provided in this report is not intended for diagnostic purposes. It is provided for informational purposes only. NORD recommends that affected individuals seek the advice or counsel of their own personal physicians.
It is possible that the title of this topic is not the name you selected. Please check the Synonyms listing to find the alternate name(s) and Disorder Subdivision(s) covered by this report
This disease entry is based upon medical information available through the date at the end of the topic. Since NORD's resources are limited, it is not possible to keep every entry in the Rare Disease Database completely current and accurate. Please check with the agencies listed in the Resources section for the most current information about this disorder.
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Last Updated: 8/7/2007
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