Incomplete Penetrance of the C9ORF72 Hexanucleotide Repeat Expansions: Frequency in a Cohort of Geriatric Non-Demented Subjects

Article type: Short Communication

Authors: Galimberti, Daniela^a | Arosio, Beatrice^b | Fenoglio, Chiara^a | Serpente, Maria^a | Cioffi, Sara M.G.^a | Bonsi, Rossana^a | Rossi, Paolo^b | Abbate, Carlo^b | Mari, Daniela^b | Scarpini, Elio^a

Affiliations: [a] Neurology Unit, Department of Pathophysiology and Transplantation, University of Milan, Fondazione Cà Granda, IRCCS Ospedale Policlinico, Milan, Italy | [b] Geriatric Unit, Department of Clinical Sciences and Community Health, University of Milan, Fondazione Cà Granda, IRCCS Ospedale Policlinico, Milan, Italy

Correspondence: [*] Correspondence to: Dr. Daniela Galimberti, Neurology Unit, Department of Pathophysiology and Transplantation, University of Milan, Fondazione Cà Granda, IRCCS Ospedale Policlinico, Milan, Italy. Tel.: +39 02 55033847; Fax: +39 02 55036580; E-mail: [email protected].

Abstract: We genotyped for the C9ORF72 hexanucleotide repeat expansion a population of 156 non-demented elderly subjects, recruited in a geriatric unit as control group for association studies in patients with Alzheimer's disease (AD), and found two carriers (1.2%). The first was referred for subjective memory complaints, at age 81. He was followed up until age 84 and did not develop dementia. The second was an 80-year old volunteer (spouse and caregiver of a patient with AD), non-demented at time of recruitment. We have not had information on her condition since that time. These results suggest that the penetrance of the mutation is definitely incomplete.

Keywords: C9ORF72 hexanucleotide repeat expansion, dementia, elderly, frontotemporal lobar degeneration, penetrance

DOI: 10.3233/JAD-131172

Journal: Journal of Alzheimer's Disease, vol. 39, no. 1, pp. 19-22, 2014