Figure 1.

FISH using the Vysis Extra Signal (ES) probe reveals a normal result yielding two green chromosome 22 and two red chromosome 9 signals (A); one green, one red, and one red-green fusion signal, representing a pattern that could be artifact due to coincidental juxtaposition of red and green signals, or it could represent BCR-ABL translocation with concomitant loss of chromosome 9 material proximal to the breakpoint, or finally it could represent an insertion of bcr into the chromosome 9 long arm at the abl locus (B); typical findings in CML (p210 breakpoint) yielding one green, one red, one residual red, and one red-green fusion signal (C); and typical findings in ALL (p190 breakpoint) yielding one green, one red, and two red-green fusions (D).