TY - JOUR T1 - C9orf72 repeat expansion in amyotrophic lateral sclerosis in the kii peninsula of japan AU - Ishiura H, Takahashi Y, Mitsui J, et al Y1 - 2012/09/01 N1 - 10.1001/archneurol.2012.1219 JO - Archives of Neurology SP - 1154 EP - 1158 VL - 69 IS - 9 N2 - Background  In the Kii peninsula of Japan, high prevalences of amyotrophic lateral sclerosis (ALS) and parkinsonism-dementia complex have been reported. There are 2 major foci with a high prevalence, which include the southernmost region neighboring the Koza River (Kozagawa and Kushimoto towns in Wakayama prefecture) and the Hohara district (Mie prefecture).Objective  To delineate the molecular basis of ALS in the Kii peninsula of Japan, we analyzed hexanucleotide repeat expansion in the chromosome 9 open reading frame 72 (C9ORF72) gene, which has recently been identified as a frequent cause of ALS and frontotemporal dementia in the white population.Design  Case series.Setting  University hospitals.Patients  Twenty-one patients (1 familial patient and 20 sporadic patients) with ALS from Wakayama prefecture, and 16 patients with ALS and 16 patients with parkinsonism-dementia complex originating from Mie prefecture surveyed in 1994 through 2011 were enrolled in the study. In addition, 40 probands with familial ALS and 217 sporadic patients with ALS recruited from other areas of Japan were also enrolled in this study.Main Outcome Measures  After screening by repeat-primed polymerase chain reaction, Southern blot hybridization analysis was performed to confirm the expanded alleles.Results  We identified 3 patients with ALS (20%) with the repeat expansion in 1 of the 2 disease foci. The proportion is significantly higher than those in other regions in Japan. Detailed haplotype analyses revealed an extended shared haplotype in the 3 patients with ALS, suggesting a founder effect.Conclusions  Our findings indicate that the repeat expansion partly accounts for the high prevalence of ALS in the Kii peninsula. SN - 0003-9942 M3 - doi: 10.1001/archneurol.2012.1219 UR - http://dx.doi.org/10.1001/archneurol.2012.1219 ER -