title: Expanded C9ORF72 hexanucleotide repeat in depressive pseudodementia.
abstract: OBJECTIVE
  Expanded hexanucleotide repeats in C9ORF72 are a common genetic cause of frontotemporal dementia and amyotrophic lateral sclerosis. Repeat expansions have also been detected infrequently in other disorders, including Alzheimer disease, dementia with Lewy bodies, and parkinsonian disorders.
  
  
  METHODS
  A consecutive series of 31 cases from the brain bank for neurodegenerative disorders at Mayo Clinic was screened to assess the incidence of the expanded C9ORF72 repeat in cases of depressive pseudodementia. The presence of the hexanucleotide repeat was established using immunohistochemistry with a highly disease-specific antibody (C9RANT), and was further validated in carriers using repeat-primed polymerase chain reaction and Southern blotting. Two individuals harbored the C9ORF72 repeat expansion. Both patients were men with refractory depression. One patient experienced drug-induced parkinsonism and sudden-onset dementia, while the other patient had a more insidious disease course suspected to be Alzheimer disease.
  
  
  CONCLUSIONS
  This report increases the range of clinicopathologic presentations of C9ORF72 expanded hexanucleotide repeat to include psychiatric disorders such as depressive pseudodementia.
authors.affiliation: Department of Neuroscience, Mayo Clinic, Jacksonville, Florida2Mayo Graduate School, Mayo Clinic College of Medicine, Rochester, Minnesota.
authors.forename: Kevin F
authors.initials: KF
authors.lastname: Bieniek
authors.affiliation: Department of Neuroscience, Mayo Clinic, Jacksonville, Florida.
authors.forename: Marka
authors.initials: M
authors.lastname: van Blitterswijk
authors.affiliation: Department of Neuroscience, Mayo Clinic, Jacksonville, Florida.
authors.forename: Matthew C
authors.initials: MC
authors.lastname: Baker
authors.affiliation: Department of Neuroscience, Mayo Clinic, Jacksonville, Florida.
authors.forename: Leonard
authors.initials: L
authors.lastname: Petrucelli
authors.affiliation: Department of Neuroscience, Mayo Clinic, Jacksonville, Florida.
authors.forename: Rosa
authors.initials: R
authors.lastname: Rademakers
authors.affiliation: Department of Neuroscience, Mayo Clinic, Jacksonville, Florida.
authors.forename: Dennis W
authors.initials: DW
authors.lastname: Dickson
mesh_terms: D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000235:genetics* / Q000473:pathology; D000690:Amyotrophic Lateral Sclerosis / Q000235:genetics* / Q000473:pathology / Q000523:psychology; D000073885:C9orf72 Protein; D042622:DNA Repeat Expansion / Q000235:genetics*; D003863:Depression / Q000235:genetics*; D003937:Diagnosis, Differential; D005162:Factitious Disorders / Q000235:genetics*; D005260:Female; D057180:Frontotemporal Dementia / Q000235:genetics*; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D008875:Middle Aged; D011506:Proteins / Q000235:genetics*
chemical_list: D000073885:C9orf72 Protein; C568651:C9orf72 protein, human; D011506:Proteins
references.citation: Neuron. 2011 Oct 20;72(2):257-68
references.pmid: 21944779
references.citation: Arch Gen Psychiatry. 1981 Dec;38(12):1359-64
references.pmid: 7316680
references.citation: Ann Neurol. 2013 Nov;74(5):699-708
references.pmid: 23836460
references.citation: J Affect Disord. 2007 Aug;101(1-3):123-9
references.pmid: 17184844
references.citation: Acta Neuropathol. 2011 Dec;122(6):691-702
references.pmid: 22101323
references.citation: Clin Genet. 2013 Mar;83(3):279-83
references.pmid: 22650353
references.citation: Neuron. 2011 Oct 20;72(2):245-56
references.pmid: 21944778
references.citation: J Neurol Neurosurg Psychiatry. 1990 Mar;53(3):254-9
references.pmid: 2324757
references.citation: Acta Neuropathol. 2013 Jul;126(1):51-7
references.pmid: 23604587
references.citation: J Alzheimers Dis. 2012;31(2):447-52
references.pmid: 22571983
references.citation: N Engl J Med. 2012 Jan 19;366(3):283-4
references.pmid: 22216764
references.citation: J Neurol Neurosurg Psychiatry. 2012 Oct;83(10):1031-2
references.pmid: 22832738
references.citation: Brain Res. 2013 Feb 7;1495:86-94
references.pmid: 23228724
references.citation: Acta Neuropathol. 2013 Feb;125(2):289-302
references.pmid: 23053135
references.citation: Neuron. 2013 Feb 20;77(4):639-46
references.pmid: 23415312
references.citation: Brain. 2013 Feb;136(Pt 2):385-91
references.pmid: 23413259
references.citation: Arch Neurol. 2010 Oct;67(10):1238-50
references.pmid: 20937952
references.citation: Alzheimers Res Ther. 2012 Oct 03;4(5):38
references.pmid: 23034079
references.citation: Trends Neurosci. 2013 Aug;36(8):450-9
references.pmid: 23746459
references.citation: Science. 2013 Mar 15;339(6125):1335-8
references.pmid: 23393093