{"title":"C9orf72 repeat expansions in Wakayama: One potential cause of amyotrophic lateral sclerosis in the Kii Peninsula, Japan","authors":"","doi":"10.1016/j.jns.2024.123209","DOIUrl":null,"url":null,"abstract":"<div><p>A cluster of cases of amyotrophic lateral sclerosis (ALS) exists in the southern part of the Kii Peninsula in Japan. Although both genetic and environmental factors are thought to be causative, the critical cause of this cluster has not been identified. <em>C9orf72</em> is the most common genetic factor in both familial and sporadic <em>C9orf72</em>-related ALS in people of European ancestry, but it is rare among Japanese populations. However, a previous report revealed that the frequency of <em>C9orf72</em>-related ALS was significantly higher in the cluster area. We evaluated the proportion of <em>C9orf72</em> hexanucleotide repeat expansions in 99 cases of ALS diagnosed in Wakayama Prefecture, including the cluster area, by using repeat-primed polymerase chain reaction and fluorescence fragment length analysis. We found that 2 of the 99 patients (0 % of those with familial ALS and 2.4 % of those with sporadic ALS) had hexanucleotide repeat expansions in <em>C9orf72</em>, and long-read sequencing revealed that these expansions were causative. No expansions were observed among 90 patients with Parkinson's disease or among 90 healthy controls. Haplotype analysis with long-read sequencing data revealed that the two patients with repeat expansions shared the common haplotype with that previously reported in Finnish patients with <em>C9orf72</em>-related ALS, which suggests a founder effect. <em>C9orf72</em> was thought to be a rare causative gene in Japan, but this study revealed that it may be relatively common in Wakayama Prefecture.</p></div>","PeriodicalId":17417,"journal":{"name":"Journal of the Neurological Sciences","volume":null,"pages":null},"PeriodicalIF":3.6000,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of the Neurological Sciences","FirstCategoryId":"3","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0022510X24003447","RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CLINICAL NEUROLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
A cluster of cases of amyotrophic lateral sclerosis (ALS) exists in the southern part of the Kii Peninsula in Japan. Although both genetic and environmental factors are thought to be causative, the critical cause of this cluster has not been identified. C9orf72 is the most common genetic factor in both familial and sporadic C9orf72-related ALS in people of European ancestry, but it is rare among Japanese populations. However, a previous report revealed that the frequency of C9orf72-related ALS was significantly higher in the cluster area. We evaluated the proportion of C9orf72 hexanucleotide repeat expansions in 99 cases of ALS diagnosed in Wakayama Prefecture, including the cluster area, by using repeat-primed polymerase chain reaction and fluorescence fragment length analysis. We found that 2 of the 99 patients (0 % of those with familial ALS and 2.4 % of those with sporadic ALS) had hexanucleotide repeat expansions in C9orf72, and long-read sequencing revealed that these expansions were causative. No expansions were observed among 90 patients with Parkinson's disease or among 90 healthy controls. Haplotype analysis with long-read sequencing data revealed that the two patients with repeat expansions shared the common haplotype with that previously reported in Finnish patients with C9orf72-related ALS, which suggests a founder effect. C9orf72 was thought to be a rare causative gene in Japan, but this study revealed that it may be relatively common in Wakayama Prefecture.
期刊介绍:
The Journal of the Neurological Sciences provides a medium for the prompt publication of original articles in neurology and neuroscience from around the world. JNS places special emphasis on articles that: 1) provide guidance to clinicians around the world (Best Practices, Global Neurology); 2) report cutting-edge science related to neurology (Basic and Translational Sciences); 3) educate readers about relevant and practical clinical outcomes in neurology (Outcomes Research); and 4) summarize or editorialize the current state of the literature (Reviews, Commentaries, and Editorials).
JNS accepts most types of manuscripts for consideration including original research papers, short communications, reviews, book reviews, letters to the Editor, opinions and editorials. Topics considered will be from neurology-related fields that are of interest to practicing physicians around the world. Examples include neuromuscular diseases, demyelination, atrophies, dementia, neoplasms, infections, epilepsies, disturbances of consciousness, stroke and cerebral circulation, growth and development, plasticity and intermediary metabolism.