Novel Mutations of the GNE Gene in Distal Myopathy with Rimmed Vacuoles Presenting with Very Slow Progression

We report novel compound heterozygous mutations of the UDP-N-acetylglucosamine-2-epimerase and N-acetylmannosamine kinase (GNE) gene, c.302G>A (p.R101H) and c.617-4A>G, in a Japanese family with distal myopathy with rimmed vacuoles (DMRV) presenting with slow progression. The three patients could stand and walk even 36, 34, and 39 years after onset, respectively, although affected individuals become wheelchair bound on average 12 years after onset of the disease. The clinical spectrum of DMRV seems to be wider than previously thought in terms of both the clinical course and the severity of the disease.