What condition is 80% of Duchenne Muscular Dystrophy cases attributed to?

Duchenne Muscular Dystrophy (DMD) is primarily caused by mutations in the dystrophin gene located on the X chromosome. Among the various types of mutations that can occur in this gene, deletions account for approximately 80% of the cases of DMD. These deletions result in the loss of important coding sequences, leading to a nonfunctional dystrophin protein, which is essential for muscle fiber integrity and function.

Dystrophin plays a critical role in connecting the cytoskeleton of muscle cells to the extracellular matrix. When altered due to deletions, it disrupts this connection, leading to muscle degeneration and the progressive weakness characteristic of DMD. Other types of mutations, such as single nucleotide substitutions, inversions, and duplications, occur but are much less common in this specific condition. This understanding is key for genetic counseling, diagnostics, and developing targeted therapies for patients with DMD.