Principal component analyses in the present cohort revealed a significant relationship between rounded TDP-43 inclusions and clinicopathological group only, which is consistent with the finding of rounded TDP-43 inclusions in the FTLD cohort, and the circumferential TDP-43 inclusions in the overlapping clinicopathological FTLD-ALS cohort. This evidence concerns the gene TARDBP and amyotrophic lateral sclerosis.