Duplications of (a) 15q13.1-q13.2 (BP3-BP4), and (b) 15q13.3 (BP4-BP5) identified in 2 of 960 normal control samples using the HumanHap300 Genotyping BeadChip (Illumina, San Diego, CA). Data shows probe position (x-axis) against smoothed LogR intensity ratio (red/black bars) and B-allele frequency (blue/black circles) (y-axis) for probes on chromosome 153. Data points within the duplicated regions are shown in colour, while those outside are shown in black. Green shaded boxes indicated segmental duplications. Within the limits of resolution of this data, the BP4-BP5 duplication appears to be the reciprocal event to the recurrent deletion shown in Figure 1. However, the BP3-BP4 duplication is clearly smaller than the deletion identified in patient 543/06, with breakpoints located in unique sequence (not in segmental duplications). No deletions of BP3-BP4 or BP4-BP5 were observed in this control population.