A Case of Nonaka Myopathy Confirmed by GNE Mutation

Nonaka myopathy (NM) or distal myopathy with rimmed vacuoles (DMRV) is an autosomal recessively inherited neuromuscular disorder characterized by early adult-onset weakness of distal muscles, rimmed vacuoles in muscle biopsy, and mutations in the UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase (GNE) gene. The authors describe a patient with typical clinical features of NM confirmed by GNE mutation. Mutation analysis of the GNE gene revealed that the patient was a compound heterozygous for V572L and C13S mutations.

Nonaka Myopathy: A case report

Nonaka myopathy (NM) or distal myopathy with rimmed vacuoles was an autosomal recessive muscle disease with preferential involvement of the tibialis anterior and sparing quadriceps muscles in young adulthood. Patients with NM usually showed slightly elevated serum creatine kinase (CK) levels and characteristic rimmed vacuoles in muscle biopsy. Recently, the UDP-N-acetylglucosamine-2-epimerase/N-ace-tylmannosamine kinase (GNE) gene was identified as the identified as the causative gene for NM. Here we reported a NM patient carrying homozygous mutations (V572L) of the GNE gene. To the best of our knowledge, this was the first report of genetically confirmed NM in Korea and NM should be included in the differential diagnosis of slowly progressive weakness of distal legs.