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Questions about rare diseases?
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Disease at a Glance

Summary
Monomelic amyotrophy (MMA) is a rare disease that causes muscle weakness in the upper extremities. MMA affects the lower motor neurons. Lower motor neurons are cells that help communicate information from the brain to the muscles that are involved in movement (skeletal muscles). Specifically, Monomelic amyotrophy causes weakness and loss of muscle mass in the arms and fingers. The disease is most common in Asia, especially in Japan and India. Males are more likely to develop the disease than females. The exact cause of Monomelic amyotrophy is unknown. Monomelic amyotrophy can sometimes run in families, but it is not thought to be caused by a specific genetic change. Diagnosis of the disease is based on imaging studies and electromyography (EMG) consistent with the disease.
Summary
Monomelic amyotrophy (MMA) is a rare disease that causes muscle weakness in the upper extremities. MMA affects the lower motor neurons. Lower motor neurons are cells that help communicate information from the brain to the muscles that are involved in movement (skeletal muscles). Specifically, Monomelic amyotrophy causes weakness and loss of muscle mass in the arms and fingers. The disease is most common in Asia, especially in Japan and India. Males are more likely to develop the disease than females. The exact cause of Monomelic amyotrophy is unknown. Monomelic amyotrophy can sometimes run in families, but it is not thought to be caused by a specific genetic change. Diagnosis of the disease is based on imaging studies and electromyography (EMG) consistent with the disease.Monomelic amyotrophy (MMA) is a rare disease that causes muscle weakness in the upper extremities. MMA affects the lower motor neurons. Lower motor neurons are cells that help communicate information from the brain to the muscles that are involved in movement (skeletal muscles). Specifically, Monomelic amyotrophy causes weakness and loss of muscle mass in the arms and fingers. The disease is most common in Asia, especially in Japan and India. Males are more likely to develop the disease than females. The exact cause of Monomelic amyotrophy is unknown. Monomelic amyotrophy can sometimes run in families, but it is not thought to be caused by a specific genetic change. Diagnosis of the disease is based on imaging studies and electromyography (EMG) consistent with the disease.
Resource(s) for Medical Professionals and Scientists on This Disease:
  • Orphanet  provides GARD with information for this disease.
  • RARe-SOURCE™  offers rare disease gene variant annotations and links to rare disease gene literature.

About Monomelic amyotrophy

Many rare diseases have limited information. Currently, GARD aims to provide the following information for this disease:

  • Population Estimate:This section is currently indevelopment.
  • Symptoms:May start to appear as a Teenager and as an Adult.
  • Cause:GARD does not currently have information about the cause of this disease.
  • Organizations:GARD is not currently aware of organizations specific to this disease.
  • Categories:Neurological Diseases
When Do Symptoms of Monomelic amyotrophy Begin?
Symptoms of this disease may start to appear as a Teenager and as an Adult.

The age symptoms may begin to appear differs between diseases. Symptoms may begin in a single age range, or during several age ranges. The symptoms of some diseases may begin at any age. Knowing when symptoms may have appeared can help medical providers find the correct diagnosis.
Prenatal
Before Birth
Newborn
Birth-4 weeks
Infant
1-23 months
Child
2-11 years
Adolescent Selected
12-18 years
Adult Selected
19-65 years
Older Adult
65+ years
Symptoms may start to appear as a Teenager and as an Adult.
This information comes from Orphanet

Symptoms

The types of symptoms experienced, and their intensity, may vary among people with this disease. Your experience may be different from others. Consult your health care team for more information.

The following describes the symptom(s) associated with this disease along with the corresponding body system(s), description, synonyms, and frequency (Note: Not all possible symptoms may be listed):

8 Symptoms

8 Symptoms

8 Symptoms

Body Systems

Symptoms related to this disease may affect different systems of the body. Use the 'Filter and Sort' function to learn more about which body system(s) are affected by this disease and their associated symptom(s).

Medical Term

Abnormality of the upper limb

Frequency
Uncommon
Very frequent
Very frequent
Always
Description
An abnormality of the arm.
Synonym
Abnormality of the arm; Abnormality of the upper limb
Open detail view
8 Symptoms
This information comes from the Human Phenotype Ontology (HPO)

Causes

GARD does not currently have information about the cause of this disease.

Find Your Community

How Can Patient Organizations Help?

Patient organizations can help patients and families connect. They build public awareness of the disease and are a driving force behind research to improve patients' lives. They may offer online and in-person resources to help people live well with their disease. Many collaborate with medical experts and researchers.

Services of patient organizations differ, but may include:

  • Ways to connect to others and share personal stories
  • Easy-to-read information
  • Up-to-date treatment and research information
  • Patient registries
  • Lists of specialists or specialty centers
  • Financial aid and travel resources

Please note: GARD provides organizations for informational purposes only and not as an endorsement of their services. Please contact an organization directly if you have questions about the information or resources it provides.

View GARD's criteria for including patient organizations, which can be found under the FAQs on our About page. Request an update or to have your organization added to GARD. 

Patient Organizations

4 Organizations

Organization Name

Who They Serve

Helpful Links

Country

EveryLife Foundation for Rare Diseases
People With

Rare Diseases

Helpful Links
Country

United States

Genetic Alliance
People With

Rare Diseases

Helpful Links
Country

United States

Global Genes
People With

Rare Diseases

Helpful Links
Country

United States

National Organization for Rare Disorders
People With

Rare Diseases

Helpful Links
Country

United States

Participating in Clinical Studies

Clinical studies are part of clinical research and play an important role in medical advances, including for rare diseases. Through clinical studies, researchers may ultimately uncover better ways to treat, prevent, diagnose, and understand human diseases.

What Are Clinical Studies?

Clinical studies are medical research involving people as participants. There are two main types of clinical studies:

  1. Clinical trials determine if a new test or treatment for a disease is effective and safe by comparing groups receiving different tests/treatments.
  2. Observational studies involve recording changes over time among a specific group of people in their natural settings.
Learn more about clinical trials from this U.S. Food & Drug Administration webpage.

Why Participate in Clinical Studies?

People participate in clinical trials for many reasons. People with a disease may participate to receive the newest possible treatment and additional care from clinical study staff as well as to help others living with the same or similar disease. Healthy volunteers may participate to help others and to contribute to moving science forward.

To find the right clinical study we recommend you consult your doctors, other trusted medical professionals, and patient organizations. Additionally, you can use ClinicalTrials.gov to search for clinical studies by disease, terms, or location.

What if There Are No Available Clinical Studies?

ResearchMatch helps connect people interested in research studies  with researchers from top medical centers across the United States. Anyone from the U.S. can register with this free program funded by NIH. Researchers from participating institutions use the database to search for and invite patients or healthy volunteers who meet their study criteria to participate.

Join the All of Us Research Program!

The All of Us Research Program is inviting 1 million people from all backgrounds across the U.S. to help build one of the most diverse health databases in history. Researchers will use the data to learn how our biology, lifestyle, and environment affect health. This may one day help them find ways to treat and prevent diseases.

What Are Clinical Studies?

Clinical studies are medical research involving people as participants. There are two main types of clinical studies:
  1. Clinical trials determine if a new test or treatment for a disease is effective and safe by comparing groups receiving different tests/treatments.
  2. Observational studies involve recording changes over time among a specific group of people in their natural settings.
Learn more about clinical trials from this U.S. Food & Drug Administration webpage.
Read More

Why Participate in Clinical Studies?

People participate in clinical trials for many reasons. People with a disease may participate to receive the newest possible treatment and additional care from clinical study staff as well as to help others living with the same or similar disease. Healthy volunteers may participate to help others and to contribute to moving science forward.

To find the right clinical study we recommend you consult your doctors, other trusted medical professionals, and patient organizations. Additionally, you can use ClinicalTrials.gov to search for clinical studies by disease, terms, or location.
Read More

What if There Are No Available Clinical Studies?

ResearchMatch helps connect people interested in research studies  with researchers from top medical centers across the United States. Anyone from the U.S. can register with this free program funded by NIH. Researchers from participating institutions use the database to search for and invite patients or healthy volunteers who meet their study criteria to participate.

Join the All of Us Research Program!

The All of Us Research Program is inviting 1 million people from all backgrounds across the U.S. to help build one of the most diverse health databases in history. Researchers will use the data to learn how our biology, lifestyle, and environment affect health. This may one day help them find ways to treat and prevent diseases.

ClinicalTrials.gov, an affiliate of NIH, provides current information on clinical research studies in the United States and abroad. Talk to a trusted doctor before choosing to participate in any clinical study. We recommend checking this site often and searching for studies with related terms/synonyms to improve results.
Search ClinicalTrials.gov for this disease
Contact a GARD Information Specialist if you need help finding more information on this rare disease or available clinical studies. Please note that GARD cannot enroll individuals in clinical studies. 
1-888-205-2311
Available toll-free Monday through Friday from 12 pm to 6 pm Eastern Time
(Except: Federal Holidays)
Contact GARD
Use the contact form to send your questions to a GARD Information Specialist.

Please allow 2 to 10 business days for us to respond.
ClinicalTrials.gov, an affiliate of NIH, provides current information on clinical research studies in the United States and abroad. Talk to a trusted doctor before choosing to participate in any clinical study. We recommend checking this site often and searching for studies with related terms/synonyms to improve results.
Search ClinicalTrials.gov for this disease
Contact a GARD Information Specialist if you need help finding more information on this rare disease or available clinical studies. Please note that GARD cannot enroll individuals in clinical studies. 
1-888-205-2311
Available toll-free Monday through Friday from 12 pm to 6 pm Eastern Time
(Except: Federal Holidays)
Contact GARD
Use the contact form to send your questions to a GARD Information Specialist.

Please allow 2 to 10 business days for us to respond.
About the Disease

Learn about symptoms, cause, support, and research for a rare disease. 

Getting a Diagnosis

Take steps toward getting a diagnosis by working with your doctor, finding the right specialists, and coordinating medical care.

Getting a Diagnosis

Take steps toward getting a diagnosis by working with your doctor, finding the right specialists, and coordinating medical care.

Last Updated: September 2024