Figure 7

BCR/ABL1 fusion resides at 9q34.1 in 3 patients. (a) A representative metaphase cell hybridized with a BCR/ABL1 D-FISH probe (Vysis) showing the presence of 1 fusion signal at der(9), 1 red signal at 9 and 2 green signals at both chromosomes 22 as seen in patients no 9 and 10. (b) A representative metaphase cell with co-hybridization of FISH probes RP11-61N10 and RP11-164N13 showing 2 fusion signals at 22 and der(9), plus 1 green signal at der(22), as seen in patients no 9 and 10. RP11-164N13 is therefore split, with the 5' BCR sequences relocated at der(9). (c) BCR/ABL1 D-FISH probe (Vysis) in patient no 8 showing 1 fusion signal at der(9), 1 red signal at 9 and 1 green signal at 22. The green signal from der(22) is deleted. (d) A representative metaphase cell with co-hybridization of FISH probes RP11-61N10 and RP11-594L10 giving a fusion signal at normal 22 and one red signal from RP11-61N10 at der(9), confirming that the BCR sequences moved to der(9) are centromeric of the breakpoint. There is again one green signal missing, because the deletion at der(22) includes not only 3' BCR but also at least 1.77 Mb distal to the breakpoint.