In Japan, it is extremely low, that is, accounting for less than 2.6% of familial ALS and 0.2% of solitary ALS (48, 49, 91) However, the C9orf72 repeat expansion has been energetically investigated in both foci of the Kii Peninsula, and abnormal repeat expansion was frequently observed 20%, three of 15 patients with ALS in the Kozagawa focus (neighboring the Koza river in the Wakayama Prefecture in the southernmost part of the Kii Peninsula) (48). The gene discussed is C9orf72; the disease is amyotrophic lateral sclerosis.