Motor axonal neuropathy associated with GNE mutations

Muscle Nerve. 2021 Mar;63(3):396-401. doi: 10.1002/mus.27102. Epub 2020 Dec 24.

Abstract

Background: Mutations in the GNE gene have been so far described as predominantly associated with distal lower-limb myopathies. Recent reports describe mutations in this gene in patients with peripheral neuropathy and motor neuron disease.

Methods: We describe three patients displaying motor neuropathy in association with GNE mutations. Clinical, electrophysiological, imaging, pathological, and genetic data are presented in a retrospective manner.

Results: The three patients had different phenotypes, ranging from mildly progressive lower limb weakness to a rapidly progressive 4-limb weakness. Genetic testing revealed GNE gene mutations in all patients; of those mutations, p.(His186Arg) has not been previously reported. All patients showed evidence of axonal motor nerve involvement on electrodiagnostic examination and/or muscle biopsy.

Conclusions: Nerve involvement associated with GNE gene mutations may be an underdiagnosed pathology and may influence clinical presentation and disease progression.

Keywords: GNE; Nonaka myopathy; inclusion body myopathy type 2; myopathy; neuropathy.

Publication types

  • Case Reports

MeSH terms

  • Action Potentials
  • Adult
  • Disease Progression
  • Distal Myopathies / genetics
  • Electrodiagnosis
  • Electromyography
  • Female
  • Genotype
  • Humans
  • Magnetic Resonance Imaging
  • Male
  • Middle Aged
  • Multienzyme Complexes / genetics*
  • Muscle, Skeletal / diagnostic imaging
  • Muscle, Skeletal / innervation
  • Muscle, Skeletal / pathology*
  • Mutation
  • Phenotype
  • Polyneuropathies / genetics*
  • Polyneuropathies / pathology
  • Polyneuropathies / physiopathology
  • Recruitment, Neurophysiological
  • Tomography, X-Ray Computed

Substances

  • Multienzyme Complexes
  • UDP-N-acetylglucosamine 2-epimerase - N-acetylmannosamine kinase

Supplementary concepts

  • Distal myopathy, Nonaka type