C9orf72 Repeat Expansion Does Not Affect the Phenotype in Primary Progressive Aphasia

J Alzheimers Dis. 2020;78(3):919-925. doi: 10.3233/JAD-200795.

Abstract

Primary progressive aphasia (PPA) forms the spectrum of language variants of frontotemporal lobar degeneration (FTLD), including three subtypes each consisting of distinctive speech and language features. Repeat expansion in C9orf72 gene is the most common genetic cause of FTLD. However, thus far only little is known about the effects of the C9orf72 repeat expansion on the phenotype of PPA. This retrospective study aimed at determining the differences between the PPA phenotypes of the C9orf72 expansion carriers and non-carriers. Our results demonstrated no significant differences between these groups, indicating that the C9orf72 repeat expansion does not substantially affect the phenotype of PPA.

Keywords: C9orf72; frontotemporal dementia; frontotemporal lobar degeneration; primary progressive aphasia.

Publication types

  • Letter
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Anomia / genetics
  • Anomia / physiopathology
  • Aphasia, Primary Progressive / classification
  • Aphasia, Primary Progressive / genetics*
  • Aphasia, Primary Progressive / physiopathology*
  • C9orf72 Protein / genetics*
  • DNA Repeat Expansion / genetics
  • Female
  • Humans
  • Male
  • Middle Aged
  • Phenotype*
  • Primary Progressive Nonfluent Aphasia / genetics
  • Primary Progressive Nonfluent Aphasia / physiopathology
  • Retrospective Studies

Substances

  • C9orf72 Protein
  • C9orf72 protein, human