Absence of upregulated genes associated with protein accumulations in desmin myopathy.

In desmin myopathy but not hereditary inclusion-body myopathy (hIBM), there is accumulation of myofibrillar proteins including desmin, myotilin, dystrophin, gelsolin, actin, and CDC kinase. To assess the cause of protein excess, we studied the genes coding the accumulated proteins in desmin myopathy, hIBM, and controls. No differences were found among them. In desmin myopathy, protein accumulation is not due to upregulation of genes triggered by mutant desmin, but rather to posttranslational disassembly of intermediate filaments.