Variable mosaic copy loss in DBA gene regions. BAF plots of chromosome 3 (A) and 15 (B). The heterozygous region of the BAF is displayed, showing a normal individual with most heterozygous BAFs clustering about 0.5 (top panel). A progressively increasing mosaicism is evident in patient 802 (middle panel) as a splay in the heterozygous BAF region that increases approaching the telomere. Mosaicism is more obvious in 802-2 as a bifurcation of the heterozygous BAF region (bottom panel). (B) BAF plot from a normal individual's chromosome 15q (top panel). Chromosome 15 mosaicism is evident in patient 1786 (bottom panel). The regions displayed include the long arms of the respective chromosomes, corresponding to the boxed region in the chromosome ideogram. Dashed horizontal lines in the BAF plots indicated regions grouped for mosaicism analysis. The fraction of the population with monosomy in each analyzed regions is indicated above the BAF plot in each region analyzed and is outlined in the charts to the right. The illustration on the right depicts variable chromosome 15 mosaic monosomy corresponding to the fractional mosaicism identified for sample 1786.