title: Idiopathic Parkinson's disease phenotype related to C9ORF72 repeat expansions: contribution of the neuropsychological assessment.
abstract: BACKGROUND
  Expanded GGGGCC hexanucleotide repeats in the non-coding region of the C9ORF72 gene was recently identified as being responsible for over 40% of the cases of amyotrophic lateral sclerosis associated with frontotemporal lobar degeneration, in various extrapyramidal syndromes including supranuclear gaze palsy and corticobasal degeneration, and in addition, has been found to be a rare genetic cause of isolated Parkinsonism. To our knowledge, there is no published data concerning the neuropsychological evaluation of patients diagnosed with idiopathic Parkinson's disease related with C9ORF72 repeat expansions.
  
  
  METHODS
  We report the results of the comprehensive neuropsychological evaluation in a newly described case in the literature (the sixth) of a patient presenting isolated idiopathic Parkinson's disease associated with C9ORF72 repeat expansions.The decrease in the patient's prefrontal functions resulted in a slight decrease in global efficiency. These abnormalities did not appear to be different, with respect to the deficit observed and the intensity of the cognitive impairment, from those classically observed in cases of sporadic idiopathic Parkinson's disease. Our patient also exhibited a significant impairment in visual gnosis.
  
  
  CONCLUSIONS
  If confirmed in other patients, visuoperceptive deficits in idiopathic Parkinson's disease could represent a red flag that should prompt the clinician to perform addition diagnostic procedures. A thorough neuropsychological assessment may prove to be useful for detecting idiopathic Parkinson's disease in patients who are suspected of having repeat abnormalities of C9ORF72 expansions.
authors.affiliation: University of Tours, France. karl.mondon@med.univ-tours.fr.
authors.forename: Mariam
authors.initials: M
authors.lastname: Annan
authors.forename: Émilie
authors.initials: É
authors.lastname: Beaufils
authors.forename: Ursule-Catherine
authors.initials: UC
authors.lastname: Viola
authors.forename: Patrick
authors.initials: P
authors.lastname: Vourc'h
authors.forename: Caroline
authors.initials: C
authors.lastname: Hommet
authors.forename: Karl
authors.initials: K
authors.lastname: Mondon
mesh_terms: D000073885:C9orf72 Protein; D003071:Cognition; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D018895:Microsatellite Repeats; D008875:Middle Aged; D009483:Neuropsychological Tests; D016366:Open Reading Frames; D010300:Parkinson Disease / Q000235:genetics* / Q000503:physiopathology / Q000523:psychology*; D010641:Phenotype; D011506:Proteins / Q000235:genetics*; D014796:Visual Perception
chemical_list: D000073885:C9orf72 Protein; C568651:C9orf72 protein, human; D011506:Proteins