National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Miyoshi myopathy

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Other Names:
Muscular dystrophy, distal, late onset, autosomal recessive; MM; Miyoshi distal myopathy
Categories:
This disease is grouped under:
Miyoshi myopathy is a type of muscular dystrophy characterized by muscle weakness and atrophy (wasting), mainly in the distal parts of the legs.[1] The first symptoms typically begin in young adulthood (on average 20 years of age) and include weakness and atrophy of the calves (sometimes asymmetrically), leading to inability to jump, run or walk on tiptoes. Over a period of years, the weakness and atrophy typically spread to the thighs and gluteal muscles. The forearms may become mildly atrophic with decrease in grip strength. Blood exams show an elevation of the creatine kinase (CK) often 10-100 times above the normal values.[1] It is caused by variations (mutations) in the DYSF gene. Inheritance is autosomal recessive.[2] Management may include physical therapy, use of mechanical aids, surgical intervention for orthopedic complications, respiratory aids, and social and emotional support.[1]

Miyoshi myopathy is part of the group of diseases known as  "Dysferlinopathies", which are caused by DYSF pathogenic variants.

Last updated: 7/2/2018
The disease have slow progression. Onset of signs and symptoms is typically in mid to late childhood or early-adulthood, (average age at onset of 19 years), and may include:[1]
  • Muscle weakness and atrophy (wasting), most marked in the distal parts of the legs, especially the gastrocnemius (calf) and soleus (Achilles tendon) muscles, specially in young adults
  • Inability to stand on tiptoe, retaining the ability to stand on the heels
  • Slow progression of weakness and atrophy spreading to the thighs and gluteal muscles, at which time climbing stairs, standing, and walking become difficult
  • Mildly loss of muscular mass in  forearms with decrease in grip strength; the small muscles of the hands are not affected
  • Weakness of the shoulder girdle muscles, which may occur on one side than the other.
Last updated: 7/2/2018

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.

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Medical Terms Other Names
Learn More:
HPO ID
30%-79% of people have these symptoms
Adult onset
Symptoms begin in adulthood
0003581
Difficulty standing
Difficulty in standing
0003698
Difficulty walking
Difficulty in walking
0002355
Distal upper limb amyotrophy 0007149
Exercise-induced myalgia
Exercise-induced muscle pain
Muscle pain on exercise
Muscle pain with exercise
Muscle pain, exercise-induced
[ more ] 		0003738
Pelvic girdle muscle weakness 0003749
Proximal amyotrophy
Wasting of muscles near the body
0007126
Quadriceps muscle weakness
Quadriceps weakness
0003731
Shoulder girdle muscle weakness
Weak shoulder muscles
0003547
Tibialis atrophy 0011399
Tibialis muscle weakness 0008963
5%-29% of people have these symptoms
Calf muscle hypertrophy
Increased size of calf muscles
0008981
Decreased/absent ankle reflexes 0200101
Deposits immunoreactive to beta-amyloid protein 0003791
Foot dorsiflexor weakness
Foot drop
0009027
Loss of ability to walk 0006957
Toe walking
Toe-walking
0040083
Triceps weakness 0031108
Percent of people who have these symptoms is not available through HPO
Autosomal recessive inheritance 0000007
Decreased Achilles reflex 0009072
Difficulty climbing stairs
Difficulty walking up stairs
0003551
Difficulty running 0009046
Distal amyotrophy
Distal muscle wasting
0003693
Distal muscle weakness
Weakness of outermost muscles
0002460
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
Lower limb muscle weakness
Lower extremity weakness
Lower limb weakness
Muscle weakness in lower limbs
[ more ] 		0007340
Muscle fibrillation 0010546
Muscular dystrophy 0003560
Quadriceps muscle atrophy
Wasting of quad muscles
0009050
Variable expressivity 0003828
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Last updated: 7/1/2020
Miyoshi myopathy is caused by pathogenic variants (mutations) in the DYSF gene, which encodes the dysferlin protein, a component of muscular fiber membranes. The presence and/or activity of the dysferlin protein is decreased or absent in individuals who have Miyoshi myopathy.[2] This leads to abnormalities in the integrity of the muscle fiber membrane and problems with membrane repair. Mutations in the same gene are also involved in autosomal recessive limb-girdle muscular dystrophy type 2B (LGMD2B) and other diseases. The group of diseases caused by mutations in the DYSF gene are referred as "Dysferlinopathy".[1]
Last updated: 7/2/2018
Miyoshi myopathy is inherited in an autosomal recessive manner.[1] Individuals have two copies of each gene (one copy inherited from each parent). In an individual affected with an autosomal recessive condition, both copies of the responsible gene have mutations. This means that each of the parents of an affected individual carry one mutated copy of the gene, and are therefore referred to as "carriers." Carriers of an autosomal recessive condition typically do not show signs or symptoms of the condition. When two carriers for the same condition have children together, each child has a 1 in 4 (25%) risk to have the condition, a 1 in 2 (50%) risk to be a carrier like each of the parents, and a 1 in 4 chance to not have the condition and not be a carrier. Carrier testing for at-risk relatives and prenatal diagnosis for pregnancies at increased risk are possible if the disease-causing mutations in the family are known.
Last updated: 7/2/2018
Characteristics that may make the diagnosis of Miyoshi myopathy likely are:
  • Mid- to late-childhood or early-adult onset of signs and symptoms
  • Early and predominant involvement of the calf muscles
  • Slow progression
  • Elevation of serum creatine kinase (CK) concentration, often 10-100 times normal
  • Primarily myogenic pattern on EMG (electromyography)
  • Biopsy evidence of a chronic, active myopathy without rimmed vacuoles[1]
Diagnosis typically depends on a combination of muscle biopsy and genetic testing. Muscle biopsy almost always indicates a primary dysferlinopathy (a disorder involving dysferlin, the protein absent or decreased in individuals with Miyoshi myopathy and limb-girdle muscular dystrophy type 2B). Molecular genetic testing of DYSF, the only gene associated with dysferlinopathy, is clinically available.[1]
Last updated: 6/6/2011

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.
  • The Jain Foundation sponsors genetic testing to confirm the diagnosis of dysferlinopathy.
There is currently no cure or definitive treatment for Miyoshi myopathy. Management depend on the specific signs and symptoms, and is aimed to prolong survival and improve quality of life:.[1]
  • Physical therapy and stretching exercises to promote mobility and prevent contractures
  • Use of mechanical aids such as canes, walkers, orthotics, and wheelchairs as needed to help ambulation and mobility
  • Surgical intervention as needed for orthopedic complications such as foot deformity and scoliosis
  • Use of respiratory aids when indicated
  • Social and emotional support
Because  dysferlinopathies are progressive conditions, rehabilitative interventions should be focused on slowing down the of muscle weakness and wasting progression, rather than increasing muscle strength and walking capacity at the risk of causing irreversible muscle damage. Gene therapies are under investigation.[3]
Last updated: 7/2/2018

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources

Related diseases are conditions that have similar signs and symptoms. A health care provider may consider these conditions in the table below when making a diagnosis. Please note that the table may not include all the possible conditions related to this disease.

Conditions with similar signs and symptoms from Orphanet
Differential diagnosis includes autosomal recessive limb-girdle muscular dystrophy type 2L (LGMD2L), LGMD2B and qualitative or quantitative defects of caveolin-3.
Visit the Orphanet disease page for more information.

Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Clinical Research Resources

  • The Centers for Mendelian Genomics program is working to discover the causes of rare genetic disorders. For more information about applying to the research study, please visit their website.
  • ClinicalTrials.gov lists trials that are related to Miyoshi myopathy. Click on the link to go to ClinicalTrials.gov to read descriptions of these studies.

    Please note: Studies listed on the ClinicalTrials.gov website are listed for informational purposes only; being listed does not reflect an endorsement by GARD or the NIH. We strongly recommend that you talk with a trusted healthcare provider before choosing to participate in any clinical study.
  • The Jain Foundation provides information on clinical trials and research studies for dysferlinopathy.

Patient Registry

  • A registry supports research by collecting of information about patients that share something in common, such as being diagnosed with Miyoshi myopathy. The type of data collected can vary from registry to registry and is based on the goals and purpose of that registry. Some registries collect contact information while others collect more detailed medical information. Learn more about registries.

    Registries for Miyoshi myopathy:
    Dysferlin Registry
     

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

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

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. 
    http://www.ncbi.nlm.nih.gov/omim/254130
    http://www.ncbi.nlm.nih.gov/omim/613318
    http://www.ncbi.nlm.nih.gov/omim/613319
  • 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 Miyoshi myopathy. Click on the link to view a sample search on this topic.

News

Other Conferences

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know. Submit a new question

  • My brother and I have similar symptoms and I was recently informed that it was Miyoshi distal myopathy. Could you please provide some of the latest information on this disease? See answer


  1. Aoki M. Dysferlinopathy. GeneReviews. 2015; http://www.ncbi.nlm.nih.gov/books/NBK1303/.
  2. Miyoshi myopathy. Orphanet. 2015; http://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=EN&Expert=45448.
  3. Begam M, Collier AF, Mueller AL, Roche R, Galen SS & Roche JA. Diltiazem improves contractile properties of skeletal muscle in dysferlin-deficient BLAJ mice, but does not reduce contraction-induced muscle damage. Physiological Reports. 2018; 6(11):e13727. https://www-ncbi-nlm-nih-gov.ezproxy.nihlibrary.nih.gov/pmc/articles/PMC5995314/.