C9orf72 repeat expansions in rapid eye movement sleep behaviour disorder.
BACKGROUND
A large hexanucleotide repeat expansion in C9orf72 has been identified as the most common genetic cause in familial amyotrophic lateral sclerosis and frontotemporal dementia. Rapid Eye Movement Sleep Behavior Disorder (RBD) is a sleep disorder that has been strongly linked to synuclein-mediated neurodegeneration. The aim of this study was to evaluate the role of the C9orf72 expansions in the pathogenesis of RBD.


METHODS
We amplified the C9orf72 repeat expansion in 344 patients with RBD by a repeat-primed polymerase chain reaction assay.


RESULTS
We identified two RBD patients carrying the C9orf72 repeat expansion. Most interestingly, these patients have the same C9orf72 associated-risk haplotype identified in 9p21-linked amyotrophic lateral sclerosis and frontotemporal dementia families.


CONCLUSIONS
Our study enlarges the phenotypic spectrum associated with the C9orf72 hexanucleotide repeat expansions and suggests that, although rare, this expansion may play a role in the pathogenesis of RBD.
1Montreal Neurological Institute,Montreal,Quebec,Canada.
Hussein
H
Daoud
2Department of Neurology,Montreal General Hospital,McGill University,Montreal,Quebec,Canada.
Ronald B
RB
Postuma
1Montreal Neurological Institute,Montreal,Quebec,Canada.
Cynthia V
CV
Bourassa
1Montreal Neurological Institute,Montreal,Quebec,Canada.
Daniel
D
Rochefort
1Montreal Neurological Institute,Montreal,Quebec,Canada.
Maude Turcotte
MT
Gauthier
3Centre d'Études Avancées en Médecine du Sommeil,Hôpital du Sacré-Cœur de Montréal,Université de Montréal,Montreal,Quebec,Canada.
Jacques
J
Montplaisir
2Department of Neurology,Montreal General Hospital,McGill University,Montreal,Quebec,Canada.
Jean-Francois
JF
Gagnon
6Service des pathologies du sommeil,Hôpital Pitié-Salpêtrière,APHP and INSERM U975-CRICM-Pierre and Marie Curie University,Paris,France.
Isabelle
I
Arnulf
7Department of Neurology,Hôpital Gui de Chauliac,INSERM U1061,Montpellier,France.
Yves
Y
Dauvilliers
8PRES Nord de France,IFR 114,IMPRT,Neurophysiologie Clinique,Centre Hospitalier Régional Universitaire de Lille,France.
Christelle Monaca
CM
Charley
9Japan Somnology Center,Neuropsychiatric Research Institute,Tokyo Medical University,Tokyo,Japan.
Yuichi
Y
Inoue
9Japan Somnology Center,Neuropsychiatric Research Institute,Tokyo Medical University,Tokyo,Japan.
Taeko
T
Sasai
10Department of Neurology,Innsbruck Medical University,Innsbruck,Austria.
Birgit
B
Högl
2Department of Neurology,Montreal General Hospital,McGill University,Montreal,Quebec,Canada.
Alex
A
Desautels
10Department of Neurology,Innsbruck Medical University,Innsbruck,Austria.
Birgit
B
Frauscher
3Centre d'Études Avancées en Médecine du Sommeil,Hôpital du Sacré-Cœur de Montréal,Université de Montréal,Montreal,Quebec,Canada.
Valérie
V
Cochen De Cock
1Montreal Neurological Institute,Montreal,Quebec,Canada.
Guy A
GA
Rouleau
1Montreal Neurological Institute,Montreal,Quebec,Canada.
Patrick A
PA
Dion
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000073885:C9orf72 Protein; D015331:Cohort Studies; D042622:DNA Repeat Expansion / Q000235:genetics*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011506:Proteins / Q000235:genetics*; D020187:REM Sleep Behavior Disorder / Q000175:diagnosis* / Q000235:genetics*
D000073885:C9orf72 Protein; C568651:C9orf72 protein, human; D011506:Proteins