OLIG2 and multiple system atrophy: This cell had multiple other CNVs, with clustered gains on chromosome 1q, and one reported breakpoint ~ 0.5 Mb from GBA. Several other examples of clustered gains were seen in the mixed MSA case (Additional file 2: Figure S6), including a pontine olig2-positive cell (K53) with extensive gains in four chromosomes, and a gain encompassing Parkin, which is somatically unstable in cancer [78].