A novel desmin R355P mutation causes cardiac and skeletal myopathy.

A novel desmin R355P mutation has been identified in a patient with familial cardiac and skeletal myopathy. Two types of desmin storage were observed in the skeletal muscles. The spheroid-like bodies dominated in type 2 fibres while extensive accumulation of granulofilamentous material was found in type 1 fibres and in cardiomyocytes. A novel missense mutation R355P in the rod domain located in the C-terminal part of the 2B subunit is the eighth missense mutation, which changes the original aminoacid into proline. Proline is known to disrupt the alpha-helix and distort a unique stutter sequence that is critically important for proper filament assembly.