Becker muscular dystrophy

Becker muscular dystrophy (BMD) is an X-linked recessive inherited disorder characterized by slowly progressing muscle weakness of the legs and pelvis. It is a type of dystrophinopathy.^[5][3] The cause is mutations and deletions in any of the 79 exons encoding the large dystrophin protein, essential for maintaining the muscle fiber's cell membrane integrity.^[6] Becker muscular dystrophy is related to Duchenne muscular dystrophy in that both result from a mutation in the dystrophin gene, however, the hallmark of Becker is milder in-frame deletions.^[4] and hence has a milder course, with patients maintaining ambulation till 50–60 years if detected early.^[7][8]

While there is no known cure, management strategies such as physical therapy, braces, and corrective surgery may alleviate symptoms.^[9] Assisted ventilation may be required in those with weakness of breathing muscles.^[6] Several drugs designed to address the root cause are currently available including gene therapy (Elevidys).^[6]

Other medications used include glucocorticoids (Deflazacort, Vamorolone); calcium channel blockers (Diltiazem); to slow skeletal and cardiac muscle degeneration, anticonvulsants to control seizures and some muscle activity, and Histone deacetylase inhibitors (Givinostat) to delay damage to dying muscle cells.^[9][6] These patients do not require antisense drugs (Ataluren, Eteplirsen, etc.) as a certain percentage of dystrophin is already expressed.^[6]