What is the function of dystrophin?

Normal Function In skeletal and cardiac muscles, dystrophin is part of a group of proteins (a protein complex) that work together to strengthen muscle fibers and protect them from injury as muscles contract and relax.

Is dystrophin a spectrin?

(A) The central rod of dystrophin is composed of 24 spectrin-like repeat. Each repeat unit is ~110 aa in size and forms a triple α-helical bundles; a and b form the long helix while c forms the short helix.

What is the function of dystrophin and how is it altered by DMD?

Individuals with BMD genetic mutations make dystrophin that is partially functional, which protects their muscles from degenerating as badly or as quickly as in DMD. The dystrophin protein transfers the force of muscle contraction from the inside of the muscle cell outward to the cell membrane.

What happens when dystrophin is missing?

When dystrophin is missing or non-functional, the entire complex is compromised, leading to degeneration of muscle tissue. When the ability to regenerate the muscle is exhausted, muscle wasting occurs.

How is DMD diagnosed?

Diagnosis of DMD is based on the symptoms, clinical exam, and the result of a biopsy to remove a small piece of muscle for examination under a microscope. The result of genetic testing may also help confirm the diagnosis. While there is no known cure for DMD, there are treatments that can help control symptoms.

What is the difference between DMD and BMD?

Condition: Duchenne muscular dystrophy (DMD) is a genetic disease that causes progressive muscle weakness and damage. Becker muscular dystrophy (BMD) is the less severe, and less common, form of the disease.

What role does dystrophin plays in this difference between healthy and DMD Sarcomeres?

While expressed in many tissues of the body, dystrophin has the critical role of stabilizing the muscle membrane (sarcolemma) during muscle contraction and its absence results in Duchenne muscular dystrophy (DMD).

Is Becker muscular dystrophy progressive?

Becker muscular dystrophy is similar to Duchenne muscular dystrophy and is characterized by progressive muscle weakness.

How is BMD diagnosed?

DNA testing of the dystrophin gene to diagnose BMD is now widely available and is usually done from a blood sample. In many cases, the DNA test alone can tell families and doctors with a high degree of certainty whether the disease course is more likely to be BMD or DMD.