Phenotypic Variability associated with the C9ORF72 Hexanucleotide Repeat Expansion: A Sporadic Case of Frontotemporal Lobar Degeneration with Prodromal Hyposmia and Predominant Semantic Deficits

Article type: Short Communication

Authors: Abbate, Carlo^{a; *} | Arosio, Beatrice^{a; b} | Galimberti, Daniela^{c; d} | Nicolini, Paola^a | Chiara, Lo Russo^a | Rossi, Paolo Dionigi^a | Ferri, Evelyn^a | Gussago, Cristina^{a; b} | Deriz, Milena^c | Fenoglio, Chiara^{c; d} | Serpente, Maria^{c; d} | Scarpini, Elio^{c; d} | Mari, Daniela^{a; b}

Affiliations: [a] Geriatric Unit, University of Milan, Fondazione Cà Granda, IRCCS Ospedale Maggiore Policlinico, Milan, Italy | [b] Department of Medical Sciences and Community Health, University of Milan, Fondazione Cà Granda, IRCCS Ospedale Maggiore Policlinico, Milan, Italy | [c] Neurology Unit, University of Milan, Fondazione Cà Granda, IRCCS Ospedale Maggiore Policlinico, Milan, Italy | [d] Department of Pathophysiology and Transplantation, “Dino Ferrari” Center, University of Milan, Fondazione Cà Granda, IRCCS Ospedale Maggiore Policlinico, Milan, Italy

Correspondence: [*] Correspondence to: Carlo Abbate, Geriatric Unit, Fondazione Cà Granda, IRCCS Ospedale Maggiore Policlinico, Via Pace 9, 20122 Milan, Italy. Tel.: +39 02 5503 3246; Fax: +39 02 50320735; E-mail: [email protected].

Abstract: We describe a sporadic case of frontotemporal lobar degeneration, associated with the C9ORF72 mutation, with prominent behavioral changes and semantic deficits. Predominant deficits in naming, vocabulary, word comprehension, and face and object recognition emerged on neuropsychological assessment. Amnesia, behavioral changes, and isolated psychotic symptoms were also present. Hyposmia was an unspecific prodromal sign. Brain imaging showed basofrontal and temporopolar hypometabolism bilaterally, and predominantly left-sided atrophy. Levels of cerebrospinal fluid biomarkers (amyloid-β, tau and p-tau) were normal. This description further confirms the heterogeneous presentation of the C9ORF72 mutation.

Keywords: C9ORF72, frontotemporal lobar degeneration, hyposmia, phenotype, semantic dementia

DOI: 10.3233/JAD-132075

Journal: Journal of Alzheimer's Disease, vol. 40, no. 4, pp. 849-855, 2014