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

Article type: Short Communication

Authors: Haapanen, Marjut^a | Katisko, Kasper^a | Hänninen, Tuomo^b | Krüger, Johanna^{d; e} | Hartikainen, Päivi^b | Haapasalo, Annakaisa^c | Remes, Anne M.^{a; b; d; e} | Solje, Eino^{a; b; *}

Affiliations: [a] Institute of Clinical Medicine - Neurology, University of Eastern Finland, Kuopio, Finland | [b] Neuro Center, Neurology, Kuopio University Hospital, Kuopio, Finland | [c] A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland | [d] Research Unit of Clinical Neuroscience, Neurology, University of Oulu, Oulu, Finland | [e] MRC, Oulu University Hospital, Oulu, Finland

Correspondence: [*] Correspondence to: Eino Solje, MD, PhD, University of Eastern Finland –Institute of Clinical Medicine, Neurology, P.O. Box 1627 (Yliopistonranta 1C) FI-70211 Kuopio, Finland. Tel.: +358 408425553; E-mail: eino.solje@uef.fi.

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

DOI: 10.3233/JAD-200795

Journal: Journal of Alzheimer's Disease, vol. 78, no. 3, pp. 919-925, 2020