What is the Difference Between BMD and DMD?

Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are X-linked recessive disorders caused by mutations in the DMD gene located at Xp21. Both conditions are characterized by muscle weakness and degeneration, but they differ in their severity, age of onset, and rate of progression. Key differences between DMD and BMD include:

1. Protein involvement: In DMD patients, dystrophin, a protein found in muscles, is virtually absent, while BMD patients have 10% to 40% of the normal amount of dystrophin.
2. Symptom severity: DMD is more severe than BMD, with muscle weakness worsening more rapidly. Patients with DMD usually require a wheelchair by adolescence, while BMD patients experience milder symptoms and a slower progression of the disease.
3. Age of onset: Signs of DMD generally appear before age six, while BMD usually appears after eight years of age.
4. Mutation types: The clinical differences between DMD and BMD are due to different types of mutations in the Dystrophin gene. Most identified mutations are large deletions spanning one or more exons, while the remaining individuals have point mutations, mainly nonsense and frame-shift mutations (10–30%), duplications (5–15%) and intronic or 5- and 3-UTR alterations (2%).

Currently, there is no cure for either DMD or BMD, but treatments are available for patients with certain genetic mutations. Both conditions affect skeletal muscle and heart muscle, with the heart becoming weak over time, making it a fatal disorder that requires careful management.

Comparative Table: BMD vs DMD

Duchenne Muscular Dystrophy (DMD) and Becker Muscular Dystrophy (BMD) are both genetic disorders caused by mutations in the dystrophin gene, which is located on the X chromosome. The main differences between the two are the severity of the symptoms and the type of mutations involved. Here is a table comparing the differences between BMD and DMD:

BMD is characterized by the partial absence of the dystrophin protein, while DMD is characterized by the complete absence of the dystrophin protein. The severity of symptoms and the rate of progression are slower in BMD compared to DMD.