Characterization of a novel S13F desmin mutation associated with desmin myopathy and heart block in a Chinese family.

Desmin myopathy was identified in a Chinese man with complete heart block and mild proximal and distal limb weakness. A novel heterozygous missense S13F mutation of the desmin gene was found to be associated with the myopathy. Family members carrying the mutation showed a similar or milder phenotype. The mutation is located at a protein kinase-C phosphorylation site within a highly conserved nonapeptide sequence in the head domain of the desmin protein. Expression of the mutant desmin cDNA in cell lines induced large desmin accumulations associated with preservation of a filamentous network.