Figure 2

Circos plot indicating de novo copy number changes and breakpoint junctions on chromosomes 1, 5 and 12 in a patient with severe congenital abnormalities. The outer circle displays a partial chromosome ideogram (with numbers denoting megabase positions). The two grey inner circles display the log ratios and allele frequencies of the copy number profile, respectively, based on Illumina SNP-array analysis. The red dots indicate deletions. The colored lines in the middle part of the circle denote breakpoint junctions derived from mate-pair sequencing. The color indicates the junction orientation. Blue = tail-to-head; green = head-to-tail; red = head-to-head inverted; yellow = tail-to-tail inverted. This example illustrates that copy number profiling provides only a glimpse of the complexity of chromosomal aberrations.