Extension of chromosome 13q14 deletions with regard to the MIRN15A/MIRN16-1 genes. (A) Vertical bars are drawn to visualize the extent of the 13q14 deletions (ordered from left to right according to size) in CLL patients. The x- and y-axes denote the patient identification numbers and the physical position in Mb, respectively. The vertical line at around 49.5 Mb indicates the position of the MIRN15A/MIRN16-1 genes. In 2 patients (no. 44 and no. 80), biallelic deletions were present with the 2 alleles differing largely in size, allowing their distinction by copy number analysis. (B) The 4.1-Mb region around the MIRN genes. Letters denote individual SNPs that define by their presence or absence in which inter-SNP interval a breakpoint is located. The top panel shows 6 of 13 SNPs and the lower panel 11 of 48 SNPs present on the 10k and 50k arrays, respectively. The triangles denote one individual breakpoint defined by the presence of the SNP to the right (ie, on the distal side) and the absence of the SNP to the left (ie, on the proximal side). A prominent clustering of breakpoints in certain SNP intervals indicates potential recombination hot spots in this region. The table at the bottom of panel B indicates the allocation of letters and their corresponding SNPs on the 10-K and 50-K arrays.