Neurobiology of Disease (Apr 2020)

Distal motor neuropathy associated with novel EMILIN1 mutation

  • Michele Iacomino,
  • Roberto Doliana,
  • Maria Marchese,
  • Alessandra Capuano,
  • Pasquale Striano,
  • Paola Spessotto,
  • Giulia Bosisio,
  • Rosa Iodice,
  • Fiore Manganelli,
  • Paola Lanteri,
  • Alessandro Orsini,
  • Simona Baldassari,
  • Serena Baratto,
  • Floriana Fruscione,
  • Valeria Prada,
  • Paolo Broda,
  • Alessandra Tessa,
  • Giulia Bertocci,
  • Angelo Schenone,
  • Alfonso Colombatti,
  • Carlo Minetti,
  • Filippo Maria Santorelli,
  • Federico Zara,
  • Chiara Fiorillo

Journal volume & issue
Vol. 137
p. 104757

Abstract

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Elastin microfibril interface-located proteins (EMILINs) are extracellular matrix glycoproteins implicated in elastogenesis and cell proliferation.Recently, a missense mutation in the EMILIN1 gene has been associated with autosomal dominant connective tissue disorder and motor-sensory neuropathy in a single family.We identified by whole exome sequencing a novel heterozygous EMILIN1 mutation c.748C>T [p.R250C] located in the coiled coil forming region of the protein, in four affected members of an autosomal dominant family presenting a distal motor neuropathy phenotype.In affected patient a sensory nerve biopsy showed slight and unspecific changes in the number and morphology of myelinated fibers. Immunofluorescence study of a motor nerve within a muscle biopsy documented the presence of EMILIN-1 in nerve structures. Skin section and skin derived fibroblasts displayed a reduced extracellular deposition of EMILIN-1 protein with a disorganized network of poorly ramified fibers in comparison with controls.Downregulation of emilin1a in zebrafish displayed developmental delay, locomotion defects, and abnormal axonal arborization from spinal cord motor neurons. The phenotype was complemented by wild-type zebrafish emilin1a, and partially the human wild-type EMILIN1 cRNA, but not by the cRNA harboring the novel c.748C>T [p.R250C].These data suggest a role of EMILIN-1 in the pathogenesis of diseases affecting the peripheral nervous system.

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