Mosaic de novo ACTA1 mutations result in asymmetric muscle weakness

Takeaway

  • Fatty infiltrations in specific head, proximal and distal muscles are identified in de novo mosaic ACTA1 missense mutations, the latter correlating with the degree of muscle weakness asymmetry.

Why this matters

    Commonly undetected missense mutations may account for a large percentage of molecularly undiagnosed cases, such as the ACTA1 mutation.