title: Screening for C9orf72 Expansion Mutation in Serbian Patients with Early-Onset Dementia.
abstract: 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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Neurology Clinic, Clinical Center of Serbia, Belgrade, Serbia.
authors.forename: Gorana
authors.initials: G
authors.lastname: Mandic-Stojmenovic
authors.forename: Elka
authors.initials: E
authors.lastname: Stefanova
authors.forename: Valerija
authors.initials: V
authors.lastname: Dobricic
authors.forename: Ivana
authors.initials: I
authors.lastname: Novakovic
authors.forename: Tanja
authors.initials: T
authors.lastname: Stojkovic
authors.forename: Aleksandar
authors.initials: A
authors.lastname: Jesic
authors.forename: Vladimir
authors.initials: V
authors.lastname: Kostic
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000235:genetics*; D000073885:C9orf72 Protein; D003704:Dementia / Q000235:genetics*; D005260:Female; D057180:Frontotemporal Dementia / Q000235:genetics; D006579:Heterozygote; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010641:Phenotype; D011506:Proteins / Q000235:genetics*; D055771:Serbia
chemical_list: D000073885:C9orf72 Protein; C568651:C9orf72 protein, human; D011506:Proteins