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Disease Profile

Becker muscular dystrophy

Prevalence
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

US Estimated

Europe Estimated

Age of onset

Childhood

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ICD-10

G71.0

Inheritance

Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease.

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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.

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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.

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X-linked
recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.

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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.

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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.

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Not applicable

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Other names (AKA)

Benign pseudohypertrophic muscular dystrophy; Becker's muscular dystrophy; Muscular dystrophy, Becker type;

Categories

Congenital and Genetic Diseases; Heart Diseases; Nervous System Diseases;

Summary

Becker muscular dystrophy (BMD) is an inherited condition that causes progressive weakness and wasting of the skeletal and cardiac (heart) muscles. It primarily affects males.[1][2] The age of onset and rate of progression can vary. Muscle weakness usually becomes apparent between the ages of 5 and 15. In some cases, heart involvement (cardiomyopathy) is the first sign.[2] BMD is caused by a mutation in the DMD gene and is inherited in an X-linked recessive manner. BMD is very similar to Duchenne muscular dystrophy, except that in BMD, symptoms begin later and progress at a slower rate.[1] There is no cure for this condition, but there is ongoing research that shows significant promise in treating the disease. Current treatment aims to relieve symptoms and improve quality of life.[3] People with BMD may survive into their 40s or beyond.[1]

Symptoms

The symptoms of Becker muscular dystrophy (BMD) may begin anywhere from childhood to a person's early 20s.[4][5] Muscle weakness often affects the legs and pelvis, and slowly gets worse.[4] Over time, affected people begin to have difficulty walking, frequent falls, difficulty with muscle skills (such as running, hopping, and jumping), and loss of muscle mass.[3] Eventually, affected people require a wheelchair.[5] The condition also affects the heart muscles, causing dilated cardiomyopathy. This form of heart disease enlarges and weakens the heart muscle, preventing it from pumping blood efficiently. Dilated cardiomyopathy progresses rapidly and is life-threatening in many cases.[4] Other symptoms of BMD may include cognitive problems, fatigue, loss of balance and coordination, problems breathing, and muscle weakness in the arms, neck and other areas of the body.[3]

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
Abnormal urinary color
Abnormal urinary colour
Abnormal urine color

[ more ]

 0012086
Difficulty climbing stairs
Difficulty walking up stairs
0003551
Difficulty walking
Difficulty in walking
0002355
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
Exercise intolerance
Decreased ability to exercise
Inability to exercise

[ more ]

 0003546
Myalgia
Muscle ache
Muscle pain

[ more ]

 0003326
Myoglobinuria
0002913
30%-79% of people have these symptoms
Elevated hepatic transaminase
High liver enzymes
0002910
Falls
0002527
Fatigue
Tired
Tiredness

[ more ]

 0012378
Muscle spasm
0003394
Muscle weakness
Muscular weakness
0001324
5%-29% of people have these symptoms
Pes planus
Flat feet
Flat foot

[ more ]

 0001763
Skeletal muscle atrophy
Muscle degeneration
Muscle wasting

[ more ]

 0003202
Toe walking
Toe-walking
0040083
Percent of people who have these symptoms is not available through HPO
Abnormal EKG
Abnormal ECG
0003115
Adult onset
Symptoms begin in adulthood
0003581
Arrhythmia
Abnormal heart rate
Heart rhythm disorders
Irregular heart beat
Irregular heartbeat

[ more ]

 0011675
Calf muscle pseudohypertrophy
0003707
Cardiomyopathy
Disease of the heart muscle
0001638
Hyporeflexia
Decreased reflex response
Decreased reflexes

[ more ]

 0001265
Muscular dystrophy
0003560
X-linked recessive inheritance
0001419

Cause

Becker muscular dystrophy (BMD) is caused by specific mutations in the DMD gene. The DMD gene gives the body instructions to make a protein called dystrophin. This protein helps stabilize and protect muscle fibers and may play a role in chemical signaling within cells. Mutations that lead to an abnormal "version" of dystrophin that allow it to keep some of its function usually cause BMD. Muscle cells without fully functional dystrophin become damaged as muscles contract and relax with use. They then weaken and die over time, leading to the muscle weakness and heart problems in people with BMD.[4]

Diagnosis

Becker muscular dystrophy (BMD) may first be suspected in a person with signs or symptoms of BMD. Healthcare providers will often conduct neurological and muscle exams, as well as order specific laboratory tests. A careful medical history is also important to differentiate between BMD and Duchenne muscular dystrophy.[3]

Exams in a person with BMD may reveal:[3]

  • Abnormally developed bones, leading to deformities of the chest and back (scoliosis)
  • Abnormality of heart muscle function (cardiomyopathy)
  • Congestive heart failure or irregular heartbeat (arrhythmias)
  • Muscle deformities
    • Contractures of heels and legs
    • Fat and connective tissue (pseudohypertrophy) in calf muscles
  • Muscle wasting that begins in the legs and pelvis, then progresses to the muscles of the shoulders, neck, arms, and respiratory system

Laboratory tests that help confirm the diagnosis include:[3]

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.

    Treatment

    There is currently no cure for Becker muscular dystrophy (BMD), and management aims to help with symptoms and improve the quality of life. Affected people are encouraged to remain active, because inactivity (such as bed rest) can make the muscle disease worse.[3]

    Physical therapy can help with stretching tight muscles and using assistive devices; occupational therapy can help with daily living skills; and speech therapy may help those with dysphagia (difficulty swallowing). Surgery may be needed for progressive scoliosis and development of contractures.[6]

    People with BMD should be monitored for orthopedic complications. Cardiac (heart) evaluations are recommended beginning at around 10 years old, or when symptoms first begin. Evaluations should be repeated at least every two years.[7242]

    Some studies have shown that certain corticosteroids (such as prednisone or prednisolone) can slow the decline of muscle strength in people with Duchenne muscular dystophy; however, information about their use in people with BMD is limited.[7242] There are a number of additional therapies for BMD being studied.[7242] Potential future treatments for BMD may include gene therapy, exon skipping, ataluren, creatine, deacetylase inhibitors, myostatin inactivation, and cell therapy (myoblast treatment, and/or the use of stem cells).[6][7]

    Management Guidelines

      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

        Organizations Providing General Support

          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

          • MedlinePlus was designed by the National Library of Medicine to help you research your health questions, and it provides more information about this topic.
          • MedlinePlus Genetics contains information on Becker muscular dystrophy. This website is maintained by the National Library of Medicine.
          • The Merck Manuals Online Medical Library provides information on this condition for patients and caregivers.
          • 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.
            • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
            • 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 Becker muscular dystrophy. Click on the link to view a sample search on this topic.

              References

              1. Duchenne and Becker muscular dystrophy. Genetics Home Reference (GHR). 2016; https://www.ghr.nlm.nih.gov/condition/duchenne-and-becker-muscular-dystrophy.
              2. Duchenne and Becker muscular dystrophy. Orphanet. August, 2007; https://www.orpha.net/consor/cgi-bin/OC_Exp.php?Lng=EN&Expert=262.
              3. Becker's muscular dystrophy. MedlinePlus. 2016; https://www.nlm.nih.gov/medlineplus/ency/article/000706.htm.
              4. Duchenne and Becker muscular dystrophy. Genetics Home Reference (GHR). 2016; https://www.ghr.nlm.nih.gov/condition=duchenneandbeckermusculardystrophy.
              5. Muscular Dystrophy, Becker. National Organization for Rare Disorders (NORD). 2007; https://rarediseases.org/rare-diseases/muscular-dystrophy-becker/.
              6. Mandac BR. Becker Muscular Dystrophy. Medscape Reference. 2015; https://emedicine.medscape.com/article/313417-overview.
              7. Darras BT. Treatment of Duchenne and Becker Muscular Dystrophy. UpToDate. Waltham, MA: UpToDate; 2016;
              8. Becker Muscular Dystrophy. MedlinePlus. 2016; https://www.nlm.nih.gov/medlineplus/ency/article/000706.htm.
              9. Becker Muscular Dystrophy. Muscular Dystrophy Association. https://mda.org/disease/becker-muscular-dystrophy/overview.
              10. Benjamin R Mandac. Becker Muscular Dystrophy. Medscape Reference. September 3, 2015; https://emedicine.medscape.com/article/313417-overview#a6.
              11. Rosaline Quinlivan. Becker muscular dystrophy. Orphanet. September, 2009; https://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=en&Expert=98895.

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