What is the Difference Between BMD and DMD

The key difference between BMD and DMD is that BMD is a less severe inherited muscle degeneration disorder in which dystrophin protein is partially absent in muscles, while DMD is a more severe inherited muscle degeneration disorder in which dystrophin protein is completely absent in muscles.

Muscular dystrophies are genetic disorders of the muscle that cause progressive muscle degeneration and weakness. There are dozens of muscular dystrophies, such as Duchenne muscular dystrophy (DMD), Becker muscular dystrophy (BMD), facioscapulohumeral muscular dystrophy, myotonic muscular dystrophy, and limb-girdle muscular dystrophy. BMD and DMD are two different muscular dystrophies that occur due to mutations in the same gene: DMD gene.

CONTENTS

1. Overview and Key Difference
2. What is BMD 
3. What is DMD 
4. Similarities – BMD and DMD 
5. BMD vs DMD in Tabular Form
6. Summary – BMD vs DMD 

What is BMD?

BMD is a less severe inherited muscle degeneration disorder that is due to the partially absent dystrophin protein in the muscles. It is caused by a mutation in the DMD gene. The signs and symptoms of this condition may include having more difficulties with sports, having trouble climbing stairs, not being able to walk quickly, run smoothly, or maintain the running pace, having trouble lifting loads, having bigger calf muscles than normal though they are weak, and heart problems. BMD is an X-linked recessive disorder. Therefore, boys are most affected by weakness in their arm and leg movements than girls.

Moreover, BMD is diagnosed through physical examination, family history, creatine kinase (CK) level test, muscle biopsy, and genetic testing. There is no proper cure for BMD. However, BMD can be managed by slowing down the symptoms and assisting the heart using medicines, and helping the movement using braces and other physical aids.

What is DMD?

DMD is a more severe inherited disorder that causes progressive muscle degeneration and weakness. DMD is due to completely absent dystrophin proteins in muscles caused by a mutation in the DMD gene. The signs and symptoms of DMD may include frequent falls, difficulty rising from a lying or sitting position, trouble running or jumping, waddling gait, waking on the toes, bigger calf muscles though they are weak, pain and stiffness in the muscles, learning disabilities, and delayed growth. The complications that result from this condition may include trouble walking, trouble using arms, contractures, breathing problems, scoliosis, heart problems, and swallowing problems.

Moreover, DMD can be diagnosed through medical history, physical examination, enzyme test of creatinine kinase (CK), genetic testing, muscle biopsy, electrocardiography, echocardiogram, lung monitoring test, and electromyography. Furthermore, there is no proper cure for DMD. However, DMD can be managed by medicines such as corticosteroids, eteplirsen (Exondys 51), heart medications such as angiotensin-converting enzyme (ACE) inhibitors or beta blockers, therapy (range-of-motion and stretching exercises, physical exercise, braces, mobility aids, and breathing assistance), and surgery (to correct contractures).

What are the Similarities Between BMD and DMD?

• BMD and DMD are two different muscular dystrophies due to mutations in the same gene called the DMD
• Dystrophin protein may be partially or completely absent in both disorders.
• Both disorders are inherited in X linked recessive pattern.
• Boys are more affected than girls in both conditions.
• Both conditions may have similar symptoms, such as walking and running problems and bigger calf muscles.
• These conditions can be diagnosed through medical history, physical examination, enzyme tests, and genetic testing.
• They are treated through medicines and physical therapy.

What is the Difference Between BMD and DMD?

BMD is a less severe inherited muscle degeneration disorder that is due to the partial absence of dystrophin protein in the muscles, while DMD is a more severe inherited muscle degeneration disorder that is due to the complete absence of dystrophin protein in the muscles. Thus, this is the key difference between BMD and DMD. Furthermore, BMD is less common in populations, while DMD is more common in populations.

The below infographic presents the differences between BMD and DMD in tabular form for side-by-side comparison.

Summary – BMD vs DMD

BMD and DMD are two different inherited disorders that are due to mutations in the same gene. These disorders may have similar symptoms, such as progressive muscle degeneration and weakness. BMD is a less severe inherited muscle degeneration disorder compared to DMD. In BMD, dystrophin protein in the muscles is not enough though there are some dystrophins in the muscles. In DMD, dystrophin protein is completely not found in muscles. So, this summarizes the difference between BMD and DMD.

Reference:

1. “Becker Muscular Dystrophy (BMD): Symptoms & Treatment.” Cleveland Clinic.
2. “Duchenne Muscular Dystrophy (DMD) – Diseases.” Muscular Dystrophy Association.

Image Courtesy:

1. “BMD histology” By Jensflorian – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “Duchenne Muscular Dystrophy” By National Center for Advancing Translational Sciences (Public Domain) via Flickr