Clinicopathological associations with C9orf72 expansion size. (A) A Kaplan-Meier curve is shown when comparing the bottom 50% (light blue) to the top 50% (dark blue), depending on the size of the C9orf72 repeat expansion. Individuals with a smaller expansion seem to demonstrate an increased survival after onset (median: 4.9 years) as compared to individuals with a longer expansion (median: 1.8 years). The black dashed line denotes the median for each group. Of note, since only one individual received a primary diagnosis of Alzheimer’s disease, this individual was excluded from our survival analysis where we adjusted for disease subgroup as well as age at onset. (B–D) An inverse correlation is detected between the number of repeats as measured by No-Amp sequencing and C9orf72 transcripts containing intron 1b (downstream of the expansion), total poly(GP) protein levels, and total poly(GA) protein levels, respectively. Each C9orf72 expansion carrier is symbolized by a filled circle. The solid dark blue line denotes the linear regression line. Notably, a non-parametric Spearman’s test of correlation was used to assess these correlations, which is based on rank and less sensitive to outliers than parametric equivalents of this test.