How rare is Miyoshi myopathy?

Miyoshi myopathy is classified as rare. The estimated prevalence is approximately 1-9 in 1,000,000. Because rare disease data can be limited, actual numbers may differ from published estimates.

How is Miyoshi myopathy diagnosed?

Information about how Miyoshi myopathy is diagnosed is currently limited for this condition.

Are there treatments for Miyoshi myopathy?

Information about treatment options for Miyoshi myopathy is currently limited for this condition.

What complications can arise from Miyoshi myopathy?

Miyoshi myopathy primarily affects the calf muscles, leading to weakness in the lower legs. While specific complications are not detailed, this weakness can make everyday activities like walking or climbing stairs more difficult. Over time, individuals may experience increased difficulty with mobility, which can impact their independence.

How does Miyoshi myopathy affect daily life?

Living with Miyoshi myopathy can be challenging due to weakness in the lower leg muscles. This may make it hard to perform activities that require standing on tiptoes or walking for long periods. People with this condition might need to adapt their daily routines and consider using assistive devices to help with mobility.

What is the prognosis for someone with Miyoshi myopathy?

Currently, there is limited information about the long-term outlook for people with Miyoshi myopathy. Since it is a muscle condition, individuals may experience progressive weakness over time. However, specific details about life expectancy or the rate of progression are not available at this time.

Should I see a specialist for Miyoshi myopathy?

It is advisable for individuals with Miyoshi myopathy to consult a specialist, such as a neurologist or a geneticist. These professionals can provide guidance on managing symptoms and may help with genetic counseling. Regular check-ups can also help monitor the condition and address any concerns that arise.

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Miyoshi myopathy (MM) - Clinical Profile, Genes & Research | Kisho | Kisho

Rare Disease

Miyoshi myopathy

MONDO:0009685

Also known as:MMMiyoshi distal myopathyMiyoshi muscular dystrophy

Find Clinical TrialsTrials

Overview

A distal myopathy, characterized by weakness in the distal lower extremity posterior compartment (gastrocnemius and soleus muscles) and associated with difficulties in standing on tip toes.

Clinical Trials1 registered

Clinical Presentation

Built from Human Phenotype Ontology (HPO) phenotype annotations and GeneReviews clinical descriptions. Features represent findings documented across known cases — not an exhaustive list of possible symptoms.

Features include common findings: Difficulty walking (gait disturbance), Shoulder girdle muscle weakness, Difficulty climbing stairs, and Difficulty standing and others; and sometimes findings: Loss of ambulation, Myalgia, Enlarged calf muscles (calf muscle hypertrophy), and Foot dorsiflexor weakness and others.

Organ System	Phenotype Count	Example Features
Muscles	14	Shoulder girdle muscle weakness, Difficulty climbing stairs, Quadriceps muscle weakness

Diagnosis

Drawn from GeneReviews diagnostic guidelines, newborn screening panel status (RUSP), and ClinGen gene-disease validity classifications. Reflects current clinical evidence and consensus where available.

GeneReviews

Diagnostic Criteria

No consensus clinical diagnostic criteria for ANO5-related muscle disease have been published.

Suggestive Findings

ANO5-related muscle disease should be suspected in probands with the following clinical, laboratory, electrophysiology, imaging, and histopathology findings and family history.

Clinical findings

Asymmetric muscle weakness and atrophy, especially in the thigh muscles, with late adult onset (mean onset: age 35 years)

Treatment

Compiled from FDA-approved drug records, orphan drug designations, and FDA Adverse Event Reporting System (FAERS) safety data. GeneReviews management guidance is included where available.

No approved treatments are currently available for Miyoshi myopathy. The disease remains an area of unmet medical need.

GeneReviews

Management Guidelines

No clinical practice guidelines for ANO5-related muscle disease have been published. In the absence of published guidelines, the following recommendations are based on the authors' personal experience managing individuals with this disorder.

Evaluations Following Initial Diagnosis

To establish the extent of disease and needs of an individual diagnosed with ANO5-related muscle disease, the evaluations summarized (if not performed as part of the evaluation that led to the diagnosis) are recommended.

Prognosis

Based on GeneReviews surveillance recommendations, HPO phenotype frequency and severity annotations, and published prevalence estimates from Orphanet and OMIM.

GeneReviews

Surveillance Guidelines

To monitor existing manifestations, the individual's response to supportive care, and the emergence of new manifestations, the evaluations summarized in are recommended.

Table 5.

ANO5-Related Muscle Disease: Recommended Surveillance

System/Concern | Evaluation | Frequency

Neuromuscular

| Eval of muscle strength functional status | Every 6-12 mos

Research Landscape

Sourced from ClinicalTrials.gov and PubMed. Publication types are classified using NLM-curated article metadata; research type breakdowns reflect the nature of published work for this disease.

1 clinical trial registered. Interventions under study include other interventions. Research is primarily sponsored by academic and government institutions.

18 publications have been identified in PubMed for Miyoshi myopathy. Research spans Case Report / Case Series (35%), Review / Meta-Analysis (18%), and Other (12%).

Research Type	Count	% of Total
Patient case studies	6	35%

Data assembled from 6 of 12 sources · Last updated Sep 19, 2026, 4:29 PM UTC

MONDOHPOClinicalTrials.govFDAPubMedHGNCClinVarClinGenGeneReviewsOrphanetOMIMRUSP

Medical References

External Resources

Orphanet

European rare disease database

Orphanet:45448

GARD

Genetic and Rare Diseases Info Center

GARD:9676

Questions for Your Care Team

→Are any of the 1 active clinical trial a good fit for my situation?
→Are there specialists or centers of excellence for this condition in my area?
→Is there a patient registry I should consider joining?

FAQ

Frequently Asked Questions

Common questions about Miyoshi myopathy

Miyoshi myopathy is a type of muscle condition that mainly affects the muscles in the lower legs, particularly the calf muscles such as the gastrocnemius and soleus. People with this condition may notice weakness in these muscles, which can make it challenging to stand on tiptoes. This condition is classified as a distal myopathy because it affects the muscles farthest from the center of the body. The information provided is based on its definition and known characteristics. Further details about the overall impact or progression are limited in the current sources.

The most common symptom of Miyoshi myopathy includes weakness in the muscles of the lower leg. People with this condition often have difficulty standing on tiptoes due to weakness in the distal lower extremity, specifically in the muscles located in the posterior compartment of the lower leg.

Miyoshi myopathy is understood to be a genetic muscle condition. It is described as having an autosomal recessive inheritance pattern, which means that the condition is typically passed down when both parents carry a gene change. Detailed genetic causes or specific gene mutations are not provided in the available information. Associated genes include DYSF, ANO5.

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GeneReviews

Differential Diagnosis

Limb-girdle muscular dystrophy (LGMD). The differential diagnosis of limb-girdle muscular dystrophy R12 anoctamin-5-related (LGMD-R12) includes all the LGMDs (see OMIM phenotypic series LGMD, autosomal recessive and LGMD, autosomal dominant). Of particular note is LGMD-R2 dysferlin-related (formerly LGMD2B) with primarily proximal weakness. LGMD-R2 is a dysferlinopathy characterized by early weakness and atrophy of the pelvic and shoulder girdle muscles in adolescence or young adulthood, with slow progression. Distal myopathy. Muscle MRI, muscle pathology, and mode of inheritance may be useful in distinguishing between distal myopathies in the differential diagnosis of Miyoshi muscular dystrophy 3 (MMD3) . Table 2. Genes Associated with Calf-Predominant Distal Myopathies in the Differential Diagnosis of Miyoshi Muscular Dystrophy 3

Gene	Disorder	MOI	Age of Onset	Initial Muscle Group Involved	Serum CK Concentration	Muscle Biopsy
ADSS1	Distal myopathy 5 (OMIM 617030)	AR	Adolescence	Posterior compartment in legs	Mildly	Myopathic changes, rimmed vacuoles, nemaline rods
DYSF	Miyoshi myopathy 11 (See Dysferlinopathy.)	AR	19 yrs (median age at onset)	Posterior compartment in legs	Often 10-100x normal	Myopathic changes
FLNC	Myofibrillar myopathy 5 (OMIM 609524)	AD	Teenage yrs to fourth decade	Posterior compartment	Normal or slightly	—
LDB3	Myofibrillar myopathy 4 (Markesbery-Griggs distal myopathy) (OMIM 609452)	AD	40 yrs	Posterior compartment in legs	Normal or slightly	Vacuolar myofibrillar myopathy
MYOT	Myofibrillar myopathy 3 (OMIM 609200)	AD	40 yrs	Posterior anterior in legs	Slightly AD = autosomal dominant; AR = autosomal recessive; CK = creatine kinase; MOI = mode of inheritance Miyoshi myopathy 1 is characterized by muscle weakness and atrophy, most marked in the distal parts of the legs, especially the gastrocnemius and soleus muscles.	—

Source: GeneReviews — "ANO5-Related Muscle Disease"

Kisho

Miyoshi myopathy

Overview

Clinical Presentation

Diagnosis

Diagnostic Criteria

Suggestive Findings

Treatment

Management Guidelines

Evaluations Following Initial Diagnosis

Prognosis

Surveillance Guidelines

Neuromuscular

Research Landscape

Medical References

External Resources

Orphanet

GARD

Questions for Your Care Team

Questions for Your Care Team

FAQ

Frequently Asked Questions

Clinical Guidance

Explore clinical features

Differential Diagnosis

Neuromuscular

Cardiac

Genetic counseling

Treatment of Manifestations

Clinical Guidance

Therapies Under Investigation

Clinical Trials

Cardiac

Recent Publications

Miyoshi myopathy

Overview

Clinical Presentation

Diagnosis

Diagnostic Criteria

Suggestive Findings

Treatment

Management Guidelines

Evaluations Following Initial Diagnosis

Prognosis

Surveillance Guidelines

Neuromuscular

Research Landscape

Medical References

External Resources

Orphanet

GARD

Subtypes

Related Diseases

Questions for Your Care Team

Questions for Your Care Team

FAQ

Frequently Asked Questions

What is Miyoshi myopathy?

What are the symptoms of Miyoshi myopathy?

What causes Miyoshi myopathy?

How rare is Miyoshi myopathy?

How is Miyoshi myopathy diagnosed?

Are there treatments for Miyoshi myopathy?

What complications can arise from Miyoshi myopathy?

How does Miyoshi myopathy affect daily life?

What is the prognosis for someone with Miyoshi myopathy?

Should I see a specialist for Miyoshi myopathy?

Clinical Guidance

Explore clinical features

Differential Diagnosis

Neuromuscular

Cardiac

Genetic counseling

Treatment of Manifestations

Clinical Guidance

Therapies Under Investigation

Clinical Trials

Cardiac

Recent Publications