title: Japanese amyotrophic lateral sclerosis patients with GGGGCC hexanucleotide repeat expansion in C9ORF72.
abstract: BACKGROUND
  A GGGGCC hexanucleotide repeat expansion in C9ORF72 occurs on a chromosome 9p21 locus that is linked with frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) in white populations. The diseases resulting from this expansion are referred to as 'c9FTD/ALS'. It has been suggested that c9FTD/ALS arose from a single founder. However, the existence of c9FTD/ALS in non-white populations has not been evaluated.
  
  
  RESULTS
  We found two index familial ALS (FALS) patients with c9FTD/ALS in the Japanese population. The frequency of c9FTD/ALS was 3.4% (2/58 cases) in FALS. No patients with sporadic ALS (n=110) or control individuals (n=180) had the expansion. Neuropathological findings of an autopsy case were indistinguishable from those of white patients. Although the frequency of risk alleles identified in white subjects is low in Japanese, one patient had all 20 risk alleles and the other had all but one. The estimated haplotype indicated that the repeat expansion in these patients was located on the chromosome with the risk haplotype identified in white subjects.
  
  
  CONCLUSIONS
  C9ORF72 repeat expansions were present in a Japanese cohort of ALS patients, but they were rare. Intriguingly, Japanese patients appear to carry the same risk haplotype identified in white populations.
authors.affiliation: Department of Molecular Neuroscience, Brain Research Institute, Niigata University, 1-757 Asahimachi-dori, Chuo-Ku, Niigata-City, Niigata 951-8585, Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Konno
authors.forename: Atsushi
authors.initials: A
authors.lastname: Shiga
authors.forename: Akira
authors.initials: A
authors.lastname: Tsujino
authors.forename: Akihiro
authors.initials: A
authors.lastname: Sugai
authors.forename: Taisuke
authors.initials: T
authors.lastname: Kato
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Kanai
authors.forename: Akio
authors.initials: A
authors.lastname: Yokoseki
authors.forename: Hiroto
authors.initials: H
authors.lastname: Eguchi
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kuwabara
authors.forename: Masatoyo
authors.initials: M
authors.lastname: Nishizawa
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Takahashi
authors.forename: Osamu
authors.initials: O
authors.lastname: Onodera
mesh_terms: D000483:Alleles; D000690:Amyotrophic Lateral Sclerosis / Q000235:genetics* / Q000473:pathology; D001344:Autopsy; D001921:Brain / Q000473:pathology; D000073885:C9orf72 Protein; D042622:DNA Repeat Expansion; D017809:Fatal Outcome; D005260:Female; D005838:Genotype; D006239:Haplotypes; D006801:Humans; D002479:Inclusion Bodies / Q000473:pathology; D007564:Japan; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D020641:Polymorphism, Single Nucleotide; D011506:Proteins / Q000235:genetics*; D016271:Proto-Oncogene Proteins c-myc / Q000235:genetics; D013116:Spinal Cord / Q000473:pathology; D057177:TDP-43 Proteinopathies / Q000473:pathology
chemical_list: D000073885:C9orf72 Protein; C568651:C9orf72 protein, human; D011506:Proteins; D016271:Proto-Oncogene Proteins c-myc