title: Polymerase chain reaction and Southern blot-based analysis of the C9orf72 hexanucleotide repeat in different motor neuron diseases.
abstract: The GGGGCC-hexanucleotide repeat expansion in C9orf72 is the most common genetic cause of familial amyotrophic lateral sclerosis and frontotemporal dementia. This study determined the frequency of C9orf72 repeat expansions in different motor neuron diseases (amyotrophic lateral sclerosis (ALS), motor neuron diseases affecting primarily the first or the second motor neuron and hereditary spastic paraplegia). Whereas most studies on C9orf72 repeat expansions published so far rely on a polymerase chain reaction-based screening, we applied both polymerase chain reaction-based techniques and Southern blotting. Furthermore, we determined the sensitivity and specificity of Southern blotting of the C9orf72 hexanucleotide repeat in DNA derived from lymphoblastoid cell lines. C9orf72 repeat expansions were found in 27.1% out of 166 familial ALS patients, only once in 68 sporadic ALS patients, and not in 61 hereditary spastic paraplegia patients or 52 patients with motor neuron diseases affecting clinically primarily either the first or the second motor neuron. We found hints for a correlation between C9orf72 repeat length and the age of onset. Somatic instability of the C9orf72 repeat was observed in lymphoblastoid cell lines compared with DNA derived from whole blood from the same patient and therefore caution is warranted for repeat length determination in immortalized cell lines.
authors.affiliation: Department of Neurology, University of Ulm, Ulm, Germany. Electronic address: annemarie.huebers@uni-ulm.de.
authors.forename: Annemarie
authors.initials: A
authors.lastname: Hübers
authors.affiliation: Institute of Human Genetics, University of Ulm, Ulm, Germany.
authors.forename: Nicolai
authors.initials: N
authors.lastname: Marroquin
authors.affiliation: Institute of Human Genetics, University of Ulm, Ulm, Germany.
authors.forename: Birgit
authors.initials: B
authors.lastname: Schmoll
authors.affiliation: Department of Neurology, University of Magdeburg, Magdeburg, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Vielhaber
authors.affiliation: Institute of Virology, University of Ulm, Ulm, Germany.
authors.forename: Marlies
authors.initials: M
authors.lastname: Just
authors.affiliation: Institute of Epidemiology and Medical Biometry, University of Ulm, Ulm, Germany.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Mayer
authors.affiliation: Institute of Human Genetics, University of Ulm, Ulm, Germany.
authors.forename: Josef
authors.initials: J
authors.lastname: Högel
authors.affiliation: Department of Neurology, University of Ulm, Ulm, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Dorst
authors.affiliation: Institute of Virology, University of Ulm, Ulm, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Mertens
authors.affiliation: Institute of Human Genetics, University of Ulm, Ulm, Germany.
authors.forename: Walter
authors.initials: W
authors.lastname: Just
authors.affiliation: Department of Neurology, University of Ulm, Ulm, Germany.
authors.forename: Anna
authors.initials: A
authors.lastname: Aulitzky
authors.affiliation: Department of Neurology, University of Ulm, Ulm, Germany.
authors.forename: Verena
authors.initials: V
authors.lastname: Wais
authors.affiliation: Department of Neurology, University of Ulm, Ulm, Germany.
authors.forename: Albert C
authors.initials: AC
authors.lastname: Ludolph
authors.affiliation: Institute of Human Genetics, University of Ulm, Ulm, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Kubisch
authors.affiliation: Department of Neurology, University of Ulm, Ulm, Germany.
authors.forename: Jochen H
authors.initials: JH
authors.lastname: Weishaupt
authors.affiliation: Institute of Human Genetics, University of Ulm, Ulm, Germany. Electronic address: alexander.volk@uni-ulm.de.
authors.forename: Alexander E
authors.initials: AE
authors.lastname: Volk
mesh_terms: D000328:Adult; D017668:Age of Onset; D000368:Aged; D000690:Amyotrophic Lateral Sclerosis / Q000235:genetics*; D015139:Blotting, Southern; D000073885:C9orf72 Protein; D002460:Cell Line; D042622:DNA Repeat Expansion; D005260:Female; D057180:Frontotemporal Dementia / Q000235:genetics; D006801:Humans; D008214:Lymphocytes; D008297:Male; D008875:Middle Aged; D016472:Motor Neuron Disease / Q000235:genetics*; D010264:Paraplegia / Q000235:genetics; D016133:Polymerase Chain Reaction; D011506:Proteins / Q000235:genetics*
chemical_list: D000073885:C9orf72 Protein; C568651:C9orf72 protein, human; D011506:Proteins
keywords: Amyotrophic lateral sclerosis; C9orf72; Immortalized cell lines; Motor neuron diseases