Biomedicines (May 2023)

The First Large Deletion of <i>ATL3</i> Identified in a Patient Presenting with a Sensory Polyneuropathy

  • Ioanna Pyromali,
  • Laurence Richard,
  • Paco Derouault,
  • Jean-Michel Vallat,
  • Karima Ghorab,
  • Corinne Magdelaine,
  • Franck Sturtz,
  • Frédéric Favreau,
  • Anne-Sophie Lia

DOI
https://doi.org/10.3390/biomedicines11061565
Journal volume & issue
Vol. 11, no. 6
p. 1565

Abstract

Read online

Hereditary sensory neuropathies (HSN) are a heterogenous group of sensory neuropathies. Mutations in ATL3 have been described in patients presenting with hereditary sensory neuropathy IF (HSN1F), a subtype of HSN. Herein, by analyzing targeted-NGS data of a patient presenting with sensory neuropathy symptoms using the CovCopCan bioinformatic tool, we discovered the presence of a deletion of around 3kb in ATL3 from Chr11:63,401,422 to Chr11:63,398,182. This deletion affects ATL3 exons 11 and 12 and could lead to the mutation c.(1036-861_1539+329del), p.(Ala346_Gln513del). In addition, an analysis of the breakpoints’ sequences revealed the presence of Alu transposable elements at the position of the breakpoints, which pointed to a possible erroneous recombination event following a non-allelic-homologous-recombination mechanism in this area. Moreover, electronic microscopy analysis of the patient’s nerve biopsy revealed a severe rarefaction of the myelinated fibers, a demyelinating–remyelinating process, and an abnormal aspect of the endoplasmic reticulum. These findings suggest that this structural variation could potentially be responsible for the HSN symptoms of the patient. Research of structural variations in ATL3 in numerous other patients presenting similar symptoms should be broadly investigated in order to improve patients’ diagnoses.

Keywords