Adult-onset desmin myopathy in a patient with multiple sclerosis.

Desmin is an intermediate filament and the mutation of its gene, DES, mostly causes myofibrillar myopathy. A 26-year-old male patient presented with progressive proximal weakness was admitted for diagnostic evaluation. On examination, decreased visual acuity on the right-side and mild superficial sensory impairment was noted besides the proximal weakness of the extremities. High creatine kinase level in serum, and myopathic changes on electromyography were detected. Muscle biopsy showed myopathic changes with vacuoles immunoreactive to dystrophin and mild increase of the endomysium. Brain MR imaging depicted T2 hyperintense lesions, some with contrast enhancement, compatible with primary demyelinating disease. The new generation DNA sequencing revealed homozygous c.1289-2A>G mutation in DES gene, which was reported only in one family previously. Although central nervous system involvement can be present in various muscle disorders, the co-occurrence of multiple sclerosis (MS) and myopathy is very rare. In our knowledge, this is the first case with desmin-related myopathy and MS.