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What are dysferlinopathies? (Back
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Dysferlinopathies are muscular dystrophies caused by mutations in the dysferlin gene. Examples of dysferlinopathies include limb-girdle muscular dystrophy type 2B, Miyoshi myopathy, and distal anterior compartment myopathy.[1]
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Last Reviewed: 10/23/2008
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What diseases are associated with mutations in the dysferlin gene? (Back
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Dysferlin instructs the body to make a skeletal muscle protein. The protein is thought to be involved in muscle contraction and possibly membrane regeneration and repair.[2] Mutations in the dysferlin gene cause several muscular dystrophy conditions, including limb-girdle muscular dystrophy type 2B, Miyoshi myopathy, and distal anterior compartment myopathy.[3]
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Last Reviewed: 10/23/2008
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Are dysferlinopathies genetic? (Back
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Yes. Dysferlinopathies are genetic. These disorders are characterized by autosomal recessive inheritance.[4] Click here to read more about autosomal recessive inheritance.
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Last Reviewed: 10/23/2008
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What are the symptoms of dysferlinopathies? (Back
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The symptoms associated with dysferlinopathies are highly variable.[1] Some patients have no symptoms, while others develop severe functional disability.[1] Miyoshi myopathy and limb-girdle muscular dystrophy type 2B are two common forms of dysferlinopathy. We have summarized symptoms of these conditions below.
In general, muscular dystrophies cause wasting and weakening of muscles. In limb-girdle muscular dystrophies the muscles in the shoulder and pelvic girdle (the large muscles around the top part of the arms and legs) are most affected.[5] Early symptoms of limb-girdle muscular dystrophies include difficulty with running, climbing stairs, standing, and walking.[6] As the disease progresses, it may become difficult for some patients to do activities that require the arms to be raised for a duration (e.g., combing hair).[6]
In Myoshi myopathy, early symptoms are most pronounced in the distal parts of the legs (i.e., the calf muscles). Patients experience weakness and atrophy in these muscles which may make it difficult for them to stand on tiptoe. As the disease progresses the muscle weakness and atrophy may spread to the thighs and gluteal muscles, forearms, and shoulder girdle muscles, which can result in additional symptoms including difficulty climbing stairs, standing, and walking, as well as a decrease in grip strength.[4]
Symptoms in both Myoshi myopathy and limb-girdle muscular dystrophy type 2B may affect one side more than the other.[4] While these conditions differ in the initial distribution of muscle involvement, as they progress there is little clinical difference between them.[7][1] There is no significant difference in the rate of progression between them and progression is typically slow.[7]
In a recent study of 40 patients with dysferlin gene mutations by Nguyen et al., 50% of the patients were diagnosed as having typical Miyoshi myopathy or Limb-girdle muscular dystrophy type 2B. Unusual phenotypes included a mixed phenotype, which the authors referred to as "proximodistal." Thirty-five percent of the patients had this phenotype and had a combination of distal and proximal onset. Two other phenotypes included a "pseudometabolic myopathy" and "asymptomatic hyperCKemia" which were found in 10% and 5% of the patients respectively.[1]
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Last Reviewed: 10/23/2008
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What is the prognosis for patients with a dysferlinopathy? (Back
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In a previous series of patients with Miyoshi myopathy, 8 of 24 required a wheelchair after a 10-year-disease duration. This was similar to the findings of the Nguyen et al. study of 40 patients with dysferlinopathy. In addition Nguyen et al., observed few patients with a severe course of the disease. The most severe case they observed worsened over 5 years from a proximodistal onset to complete loss of ambulation, also with severe upper limb and axial weakness. The most mild case observed was of a 58-year-old man who was asymptomatic with isolated hyperCKemia.[1]
In the Nguyen et al. study, muscle inflammation, leading to a misdiagnosis of polymyositis, tended to correlate with a more severe course of disease, and they found that inflammation was most frequent in the patients with the proximodistal phenotype that they observed.[1]
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Last Reviewed: 10/23/2008
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Can a dysferlinopathy cause spine curvature and weight loss? (Back
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Curvature of the spine (scoliosis) and muscle atrophy can occur as a complication of a dysferlinopathy.[8] Diffuse muscle atrophy can give the appearance of thinning of the body. Patients with dysferlinopathy should disucss their concerns regarding the symptoms they are experiencing with their health care provider.
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Last Reviewed: 10/23/2008
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Do dysferlinopathies typically affect the muscles of the face? (Back
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No. In dysferlinopathies the muscles of the face are usually unaffected.[5][7]
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Last Reviewed: 2/20/2008
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Are patients with a dysferlinopathy able to feed themselves? (Back
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The severity of symptoms experienced by patients with a dysferlinopathy varies from patient to patient. Patients who are more severely affected may have difficulty feeding themselves as their disease progresses.
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Last Reviewed: 10/23/2008
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How can I learn about research involving dysferlinopathies? (Back
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The U.S. National Institutes of Health, through the National Library of Medicine, developed ClinicalTrials.gov to provide patients, family members, and members of the public with current information on clinical research studies. Currently, one clinical trial is identified as enrolling individuals with dysferlinopathy and 5 trials are identified as enrolling individuals with limb-girdle muscular dystrophy. To find these trials, click on the link above and use "dysferlinopathy" or "limb-girdle muscular dystrophy" as your search term. After you click on the study, review its "eligibility" criteria to determine its appropriateness. Use the study’s contact information to learn more. Check this site often for regular updates.
You can also contact the Patient Recruitment and Public Liaison (PRPL) Office at the National Institutes of Health (NIH). We recommend calling the toll-free number listed below to speak with a specialist, who can help you determine if you are eligible for any clinical trials.
Patient Recruitment and Public Liaison Office
NIH Clinical Center
Bethesda, Maryland 20892-2655
Toll-free: 800-411-1222
Fax: 301-480-9793
Email: prpl@mail.cc.nih.gov
Web site: http://clinicalcenter.nih.gov/
If you are interested in enrolling in a clinical trial, you can find helpful general information on clinical trials at the following ClinicalTrials.gov Web page.
http://clinicaltrials.gov/ct2/info/understand
A tutorial about clinical trials that can also help answer your questions can be found at the following link from the National Library of Medicine:
http://www.nlm.nih.gov/medlineplus/tutorials/cancerclinicaltrials/htm/lesson.htm
Resources on many charitable or special-fare flights to research and treatment sites and low-cost hospitality accommodations for outpatients and family members, as well as ambulance services, are listed on the Web site of the Office of Rare Diseases (ORD), part of the National Institutes of Health.
http://rarediseases.info.nih.gov/Resources.aspx?PageID=8
The National Institute of Neurological Disorders and Stroke (NINDS) is the primary NIH Institute conducting research into the muscular dystrophies, we recommend that you contact NINDS for additional information about current research projects involving dysferlinopathies.
NIH Neurological Institute
P.O. Box 5801
Bethesda, MD 20824
Toll-free: 800-352-9424
Phone: 301-496-5751
TTY: 301-468-5981
E-mail form: http://www.ninds.nih.gov/contact_us.htm
Web site: http://www.ninds.nih.gov/
In addition the following organizations support ongoing investigations for new therapies for muscular dystrophies. We recommend that you contact them directly to speak with a representative who can discuss with you in detail the research programs that are currently underway for dysferlinopathies.
Muscular Dystrophy Association
3300 East Sunrise Dr
Tucson, AZ 85718
USA
Phone: 520-529-2000
Toll-Free: 1-800-572-1717
Fax: 520-529-5300
E-mail: mda@mdausa.org
Website: http://www.mdausa.org
Muscular Dystrophy Campaign
7-11 Prescott Place
SW4 6BS
United Kingdom
Phone: (+44) 0 020 7720 8055
Fax: (+44) 0 020 7498 0670
Email: info@muscular-dystrophy.org
Web site: www.muscular-dystrophy.org
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Last Reviewed: 10/23/2008
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How can I find a genetics professional in my community? (Back
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Genetics clinics are a source of information for individuals and families regarding genetic conditions, treatment, inheritance, and genetic risks to other family members. More information about genetic consultations is available from Genetics Home Reference. To find a genetics clinic, we recommend that you contact your primary healthcare provider for a referral.
The following online resources can help you find a genetics professional in your community:
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Last Reviewed: 7/29/2011
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