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It is possible that the main title of the report Dystrophy, Myotonic 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.
Myotonic dystrophy type 1 (DM1) is an autosomal dominant, multi-system disorder that affects both smooth and skeletal muscles and may affect the central nervous system, heart, eyes, and/or endocrine systems. There are three types of DM1 that are distinguished by the severity of disease and age of onset. Mild DM1 is characterized by cataracts and sustained muscle contractions (myotonia). Classic DM1 is characterized by muscle weakness and wasting (atrophy), cataracts, myotonia and abnormalities in the heart's conduction of electrical impulses. Congenital DM1 is characterized by muscle weakness (hypotonia), difficulty breathing, mental retardation and early death.
DM1 is caused by an abnormality in the DMPK gene. Affected individuals have an increased number of copies of a portion of this gene called CTG. The greater the number of repeated copies of CTG, the more severe the disorder.
Myotonic dystrophy type 2 (DM2), formerly called proximal myotonic myopathy (PROMM) is an autosomal dominant disorder with symptoms that are similar to DM1, but tend to be milder and more variable than DM1. DM2 is an autosomal dominant genetic disorder caused by an abnormality in the ZNF9 gene on chromosome 3q. Affected individuals have an increased number of copies of a portion of this gene.
Muscular Dystrophy Association
3300 East Sunrise Drive
Tucson, AZ 85718-3208
NIH/National Institute of Arthritis and Musculoskeletal and Skin Diseases
One AMS Circle
Bethesda, MD 20892-3675
NIH/National Institute of Neurological Disorders and Stroke
P.O. Box 5801
Bethesda, MD 20824
Genetic and Rare Diseases (GARD) Information Center
PO Box 8126
Gaithersburg, MD 20898-8126
PO Box 241956
Los Angeles, CA 90024
Myotonic Dystrophy Support Group
19-21 Main Road
Nottingham, NG4 3HQ
Myotonic Dystrophy Foundation
431 Burgess Dr.
Menlo Park, CA 94025
Child Neurology Foundation
2000 West 98th Street
Bloomington, MN 55431
Medical Home Portal
Dept. of Pediatrics
University of Utah
P.O. Box 581289
Salt Lake City, UT 84158
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 www.rarediseases.org and click on Rare Disease Database under "Rare Disease Information".
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.
For additional information and assistance about rare disorders, please contact the National Organization for Rare Disorders at P.O. Box 1968, Danbury, CT 06813-1968; phone (203) 744-0100; web site www.rarediseases.org or email email@example.com
Last Updated: 7/23/2007
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