Compound heterozygous deletions in the DBT gene. Figure 4 shows CytoSure display of aCGH data with probes targeting the entire DBT gene, and zoomed-in views of two deletions: a large, >3.5-kb deletion encompassing the 5’ end of exon 11 is on the left, and a small 12-bp deletion in intron 4, three bases from the intron 4/exon 5 boundary, is on the right. The breakpoints of the small deletion are shown with vertical red lines. At the bottom is an illustration of the breakpoint PCR design, with the location of primers shown as arrows. Figure 4b shows the electropherogram indicating the deletion of 12 bases in one allele of the patient. The breakpoints are shown with two vertical red lines.