Figure 3: Clonal sSNVs identified in frontal cortex (BA9) distribute across cortical regions, with modest regional restrictions, at low mosaic fraction.

(A) The brain regions that were sampled for studies of the spread of sSNVs using MIPP-seq. Cortical lobes from which Brodmann areas/cortical structures were taken are colored (frontal, red; parietal, yellow; temporal, green; and occipital, purple; non-cortical, black). Regions separated by slashes (BA3/1/2 and BA41/42) were studied together. “A-early,” “C-early,” “B-early,” and “B-later” are four variants that we previously had studied in the frontal cortex for UMB463818. (B) The cortical distribution of a sSNV originally detected in BA9 (red rectangle) from UMB4638 (top) and UMB4643 (bottom). Tissues are arranged (left to right) in anterior to posterior cortical section ordering, and are color highlighted based on the scheme in (A). Non-cortical tissues are listed on the right. Mutations are ranked from broadest to least present across the tissues, followed by average mosaicism across samples.