Atypical Parkinsonism in distal myopathy with rimmed vacuoles

A patient with distal myopathy with rimmed vacuoles (DMRV) exhibited Parkinsonism with a severe writing tremor that responded poorly to levodopa. Molecular genetic analysis revealed that the patient had the D176V/V572L compound heterozygous mutation in the UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase (GNE) gene. Histopathological examination of a biopsied muscle specimen yielded findings compatible with those of DMRV, which is characterized by the presence of rimmed vacuoles without inflammatory cell infiltration in muscle fibers. The finding of normal cardiac meta-iodobenzylguanide uptake makes the possibility of incidental Parkinson's disease in this patient unlikely. These observations raise the possibility that atypical Parkinsonism is a rare complication of DMRV associated with GNE mutation.