A Novel Mutation of the GNE Gene in Distal Myopathy with Rimmed Vacuoles: A Case with Inflammation.
Distal myopathy with rimmed vacuoles (DMRV) is an autosomal recessive or sporadic early adult-onset myopathy caused by mutations in the UDP-N-acetylglucosamine 2-epimerase and N-acetylmannosamine kinase (GNE) gene. Characteristic pathologic features of DMRV are rimmed vacuoles on muscle biopsy and tubulofilamentous inclusion in ultrastructural study. Presence of inflammation in DMRV is unusual. We report a sporadic case of DMRV in a 40-year-old Thai man who presented with slowly progressive distal muscle weakness. Gene analysis revealed a compound heterozygous mutation of the GNE gene including a novel mutation c.1057A>G (p.K353E) and a known mutation c.2086G>A (p.V696M). The latter is the most common mutation in Thai DMRV patients. The muscle pathology was compatible with DMRV except for focal inflammation.
Department of Pathology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand ; Siriraj Neurogenetic Network, Department of Research and Development, Siriraj Hospital, Mahidol University, Bangkok, Thailand.
Jantima
J
Tanboon
Siriraj Neurogenetic Network, Department of Research and Development, Siriraj Hospital, Mahidol University, Bangkok, Thailand.
Kanjana
K
Rongsa
Siriraj Neurogenetic Network, Department of Research and Development, Siriraj Hospital, Mahidol University, Bangkok, Thailand ; Department of Internal Medicine, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand.
Manop
M
Pithukpakorn
Siriraj Neurogenetic Network, Department of Research and Development, Siriraj Hospital, Mahidol University, Bangkok, Thailand ; Department of Internal Medicine, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand.
Kanokwan
K
Boonyapisit
Siriraj Neurogenetic Network, Department of Research and Development, Siriraj Hospital, Mahidol University, Bangkok, Thailand ; Department of Internal Medicine, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand.
Chanin
C
Limwongse
Department of Pathology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand ; Siriraj Neurogenetic Network, Department of Research and Development, Siriraj Hospital, Mahidol University, Bangkok, Thailand.
Tumtip
T
Sangruchi
Distal myopathy with rimmed vacuoles; Hereditary inclusion body myopathy; Inflammation; UDP-N-acetylglucosamine 2-epimerase and N-acetylmannosamine kinase