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Disease Profile
Myotonic dystrophy type 2
Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.
1-9 / 100 000
Age of onset
Adult
ICD-10
G71.1
Inheritance
Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease.
Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype.
X-linked
dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.
dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.
X-linked
recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.
recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.
Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.
Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.
Not applicable
Other names (AKA)
Dystrophia myotonica type 2; DM2; Proximal myotonic myopathy;
Categories
Congenital and Genetic Diseases; Endocrine Diseases; Eye diseases;
Summary
Myotonic dystrophy type 2, one of the two types of myotonic dystrophy, is an
Symptoms
This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.
Medical Terms | Other Names |
Learn More:
HPO ID
|
---|---|---|
80%-99% of people have these symptoms | ||
Cataract |
Clouding of the lens of the eye
Cloudy lens
[ more ] |
0000518 |
Myotonia | 0002486 | |
Percent of people who have these symptoms is not available through HPO | ||
0000006 | ||
Decreased circulating IgG level | 0004315 | |
Decreased circulating total IgM | 0002850 | |
0000819 | ||
Elevated circulating follicle stimulating |
0008232 | |
Elevated serum creatine kinase |
Elevated blood creatine phosphokinase
Elevated circulating creatine phosphokinase
Elevated creatine kinase
Elevated serum CPK
Elevated serum creatine phosphokinase
High serum creatine kinase
Increased CPK
Increased creatine kinase
Increased creatine phosphokinase
Increased serum CK
Increased serum creatine kinase
Increased serum creatine phosphokinase
[ more ] |
0003236 |
Frontal balding | 0002292 | |
Decreased activity of gonads
|
0000135 | |
Insulin insensitivity | 0008189 | |
Iridescent posterior subcapsular cataract | 0007889 | |
Myalgia |
Muscle ache
Muscle pain
[ more ] |
0003326 |
Neck flexor weakness |
Neck flexion weakness
|
0003722 |
Oligospermia |
Low sperm count
|
0000798 |
Palpitations |
Missed heart beat
Skipped heart beat
[ more ] |
0001962 |
Proximal muscle weakness |
Weakness in muscles of upper arms and upper legs
|
0003701 |
Tachycardia |
Fast heart rate
Heart racing
Racing heart
[ more ] |
0001649 |
Type 2 muscle fiber atrophy | 0003554 |
Cause
In people with myotonic dystrophy type 2, a short piece of
Diagnosis
There are several laboratory tests that can be used to clarify the clinical diagnosis of myotonic dystrophy. One test, called electromyography (EMG), involves inserting a small needle into the muscle. The electrical activity of the muscle is studied and usually shows characteristic patterns of muscle electrical discharge.[2] The definitive test for myotonic dystrophy type 2 is a genetic test. For this test, certain
The University of Washington provides more information on
Testing Resources
- The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.
- Orphanet lists international laboratories offering diagnostic testing for this condition.
Treatment
- Ankle-foot braces, wheelchairs, or other assistive devices may be used as needed for weakness
- Defibrillator placement may be needed for arrhythmias
Cataracts can be removed for those with impaired vision- Testosterone replacement therapy may be useful for
hypogonadism in males
Myotonia is usually mild and rarely requires treatment. Routine exercise appears to help with pain control, as well as with muscle strength and endurance. The effectiveness of most medications for pain management varies. Mexilitene, which is very effective for some forms of myotonia, has helped control muscle pain in some people with this condition. Other medications that have been used with some success include gabapentin, nonsteroidal anti-inflammatory drugs (NSAIDS), low-dose thyroid replacement, low-dose steroids, and tricyclic antidepressants. Cholesterol-lowering medications should be avoided when they are associated with increased weakness.[1]
There are steps a person can take to prevent some secondary complications. Anesthetic risk may be increased, so careful assessment of heart and respiratory function before and after surgery are recommended. Affected people should also have a yearly electrocardiogram or cardiac
You can see more detailed information about the management of myotonic dystrophy type 2 on the GeneReviews Web site.
Organizations
Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.
Organizations Supporting this Disease
-
Myotonic Dystrophy Foundation
1004-A O'Reilly Avenue
San Francisco, CA 94129
Toll-free: 1-86-MYOTONIC (1-866-968-6642)
Telephone: +1-415-800-7777
E-mail: [email protected]
Website: https://www.myotonic.org -
Myotonic Dystrophy Support Group
19-21 Main Road
Gedling
Nottingham
NG4 3HQ
United Kingdom
Telephone: 0808 169 1960
E-mail: [email protected]
Website: https://www.myotonicdystrophysupportgroup.org/
Organizations Providing General Support
-
Muscular Dystrophy Association (MDA)
222 S Riverside Plaza
Suite 1500
Chicago, IL 60606
Toll-free: 1-833-275-6321 (Helpline)
E-mail: [email protected]
Website: https://www.mda.org -
Muscular Dystrophy UK
61A Great Suffolk Street
London, SE1 0BU United Kingdom
Toll-free: 0800 652 6352 (Helpline)
Telephone: (+44) 0 020 7803 4800
E-mail: [email protected]
Website: https://www.musculardystrophyuk.org/
Learn more
These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.
Where to Start
- Genetics Home Reference (GHR) contains information on Myotonic dystrophy type 2. This website is maintained by the National Library of Medicine.
- The Muscular Dystrophy Association (MDA) provides additional information about myotonic dystrophy. Click on the link to view this information.
- Myotonic Dystrophy Foundation provides additional information about Myotonic dystrophy type 2.
- The National Human Genome Research Institute's (NHGRI) website has an information page on this topic. NHGRI is part of the National Institutes of Health and supports research on the structure and function of the human genome and its role in health and disease.
- The National Organization for Rare Disorders (NORD) has a report for patients and families about this condition. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them.
In-Depth Information
- GeneReviews provides current, expert-authored, peer-reviewed, full-text articles describing the application of genetic testing to the diagnosis, management, and genetic counseling of patients with specific inherited conditions.
- The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
- Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine.
- Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
- PubMed is a searchable database of medical literature and lists journal articles that discuss Myotonic dystrophy type 2. Click on the link to view a sample search on this topic.
Selected Full-Text Journal Articles
- Mulders SAM et al., Molecular therapy in myotonic dystrophy: Focus on RNA gain-of-function. Human Molecular Genetics. 2010:19(1):R90-R97.
References
- Dalton JC, Ranum LPW, and Day JW. Myotonic Dystrophy Type 2. GeneReviews. July 3, 2013; https://www.ncbi.nlm.nih.gov/books/NBK1466/.
- Learning About Myotonic Dystrophy. National Human Genome Research Institute (NHGRI). June 4, 2012; https://www.genome.gov/25521207. Accessed 4/22/2015.
- Myotonic dystrophy. Genetics Home Reference (GHR). November 2010; https://ghr.nlm.nih.gov/condition=myotonicdystrophy. Accessed 5/11/2011.
- Myotonic muscular dystrophy. Muscular Dystrophy Association. https://mda.org/disease/myotonic-muscular-dystrophy/overview. Accessed 2/10/2014.
- Françoise Bouhour. Proximal Myotonic Myopathy. Orphanet. July, 2007; https://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=EN&Expert=606. Accessed 2/10/2014.
- David A Chad and Basil T Darras. Myotonic dystrophy: Prognosis and management. UpToDate. Waltham, MA: UpToDate; January, 2014; Accessed 2/10/2014.
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