The Right Temporal Variant of Frontotemporal Dementia Is Not Genetically Sporadic: A Case Series

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Erkoyun H. U., van der Lee S. J., Nijmeijer B., van Spaendonk R., Nelissen A., Scarioni M., ...More

JOURNAL OF ALZHEIMERS DISEASE, vol.79, no.3, pp.1195-1201, 2021 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 79 Issue: 3
  • Publication Date: 2021
  • Doi Number: 10.3233/jad-201191
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, BIOSIS, CAB Abstracts, CINAHL, EMBASE, MEDLINE, Psycinfo, Veterinary Science Database
  • Page Numbers: pp.1195-1201
  • Keywords: Dementia, frontotemporal dementia, frontotemporal lobar degeneration, genetic, GRN, MAPT, right temporal lobe, TARDBP, TDP-43 MUTATION, GENE-MUTATIONS, TAU, ATROPHY, PROGRANULIN, MRI, PHENOTYPE, CONSENSUS, DISEASE
  • Istanbul University Affiliated: Yes


Background: Right temporal variant frontotemporal dementia (rtvFTD) has been generally considered as aright sided variant of semantic variant primary progressive aphasia (svPPA), which is a genetically sporadic disorder. Recently, we have shown that rtvFTD has a unique clinical syndrome compared to svPPA and behavioral variant frontotemporal dementia. Objective: We challenge the assumption that rtvFTD is a sporadic, non-familial variant of FTD by identifying potential autosomal dominant inheritance and related genes in rtvFTD. Methods: We collected all subjects with a diagnosis of FTD or primary progressive aphasia who had undergone genetic screening (n = 284) and subsequently who had a genetic variant (n = 48) with a diagnosis of rtvFTD (n = 6) in 2 specialized memory clinics. Results: Genetic variants in FTD related genes were found in 33% of genetically screened rtvFTD cases; including MAPT (n = 4), GRN (n = 1), and TARDBP (n = 1) genes, whereas only one svPPA case had a genetic variant in our combined cohorts. Additionally, 4 out of 6 rtvFTD subjects had a strong family history for dementia. Conclusion: Our results demonstrate that rtvFTD, unlike svPPA, is not a pure sporadic, but a heterogeneous potential genetic variant of FTD, and screening for genetic causes for FTD should be performed in patients with rtvFTD.