BACKGROUND: Frontotemporal dementia (FTD) is the second most common cause of early-onset dementia (EOD), characterized by behavioral changes (behavioral variant; bvFTD) or language deficits. A hexanucleotide repeat expansion in a noncoding region of chromosome 9 open reading frame 72 (C9orf72) has been proved to be a major cause of both familial and sporadic amyotrophic lateral sclerosis or FTD, with or without concomitant motor neuron disease (MND). METHODS: The aim of this study was to assess the frequency of the C9orf72 hexanucleotide expansion in a cohort of 117 Serbian patients with EOD and to report phenotypic features of identified carriers. RESULTS: We identified 4 of 117 (3.4%) patients with EOD to have C9orf72 hexanucleotide expansions. All patients were classified in the FTD disease spectrum group (8.2%): 3 patients fulfilled the criteria for bvFTD, and 1 patient had FTD-MND. None of the patients with the C9orf72 hexanucleotide expansion fulfilled the diagnostic criteria for language variants of FTD, FTD-progressive supranuclear palsy overlap syndrome, dementia with Lewy bodies or Alzheimer's dementia. CONCLUSION: In a cohort of consecutive patients with EOD, 3.4% had the C9orf72 hexanucleotide expansion with clinical phenotypes of bvFTD or an overlap of bvFTD and MND.
BACKGROUND: Frontotemporal dementia (FTD) is the second most common cause of early-onset dementia (EOD), characterized by behavioral changes (behavioral variant; bvFTD) or language deficits. A hexanucleotide repeat expansion in a noncoding region of chromosome 9 open reading frame 72 (C9orf72) has been proved to be a major cause of both familial and sporadic amyotrophic lateral sclerosis or FTD, with or without concomitant motor neuron disease (MND). METHODS: The aim of this study was to assess the frequency of the C9orf72hexanucleotide expansion in a cohort of 117 Serbian patients with EOD and to report phenotypic features of identified carriers. RESULTS: We identified 4 of 117 (3.4%) patients with EOD to have C9orf72hexanucleotide expansions. All patients were classified in the FTD disease spectrum group (8.2%): 3 patients fulfilled the criteria for bvFTD, and 1 patient had FTD-MND. None of the patients with the C9orf72hexanucleotide expansion fulfilled the diagnostic criteria for language variants of FTD, FTD-progressive supranuclear palsy overlap syndrome, dementia with Lewy bodies or Alzheimer's dementia. CONCLUSION: In a cohort of consecutive patients with EOD, 3.4% had the C9orf72hexanucleotide expansion with clinical phenotypes of bvFTD or an overlap of bvFTD and MND.
Authors: Joshua T Geiger; Karissa C Arthur; Ted M Dawson; Liana S Rosenthal; Alexander Pantelyat; Marilyn Albert; Argye E Hillis; Barbara Crain; Olga Pletnikova; Juan C Troncoso; Sonja W Scholz Journal: Neurodegener Dis Date: 2016-05-31 Impact factor: 2.977