Abstract
Recently, C9orf72 hexanucleotide (GGGGCC) repeat expansion in intron 1 was reported to be the most common cause of sporadic and familial amyotrophic lateral sclerosis (ALS)/frontotemporal dementia (FTD) in the Caucasian population. The frequency of the intronic repeat expansion is up to 21%-57% in familial ALS and 3%-21% in sporadic ALS.In the Japanese population, the C9orf72 repeat expansion was found to account for 2.8% (3/109) of familial ALS, 0.4% (4/891) of sporadic ALS, and 0% (0/377) of normal healthy controls. Notably, among the Kii peninsula which has recorded a high incidence of ALS or ALS/PDC (parkinsonism-dementia complex), the frequency of the C9orf72 repeat expansion was 20% (3/15) indicating a high prevalence. All patients with the repeat expansion had a common risk haplotype within a narrower region than the Finnish one, suggesting a common founder effect which spread from Europe to East Asia in human migration history.Although Japanese ALS patients with the C9orf72 repeat expansion were rarer than Caucasian patients, we should check family histories of other neurological disorders such as dementia and FTD and should do genetic testing more actively even in sporadic ALS patients. Further studies of C9orf72 will clarify the pathogenesis and find the treatments for familial and sporadic ALS (or ALS/FTD).
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.