PMC4213530_01
Results of molecular cytogenetic analysis. Multicolor FISH (A) and array CGH (B) showing trisomies of chromosomes X, 4, 14, 17 and 21 (A, B) and submicroscopic aberrations: deletion of chromosome 20 and amplification of chromosome 22 (B). BCR/ABL1 positive metaphase hybridized with BCR/ABL dual fusion (DF) probe demonstrating apparent loss of green 3'BCR signal, i.e. 1F2O1G FISH pattern (caused by the insertion of the ABL1 gene into the BCR region, thus entire BCR signal remained on chromosome 22) (C). FISH with BAC probes RP11-80O7 (orange) and RP11-400P21 (green) with evidence of normal finding of 22q11.23 region matching to 3'BCR locus (two orange signals) and deletion of 20p12.1 (one green signal) (D). Detailed view of array CGH result of chromosome 22 showing amplification of the 22q11.22 region and normal 22q11.23 region pattern (E).
13039_2014_72_Fig1_HTML.jpg
PMC4213530_01_13039_2014_72_Fig1_HTML.jpg
Fig1
However, FISH with the BCR/ABL Extra Signal and BCR/ABL Dual Fusion Probes detected the BCR/ABL1 fusion with an abnormal FISH signal pattern (1F2O1G), consistent with a breakpoint within m-BCR and the loss of the 3'BCR signal from der(9) in ten out of eleven metaphases and ~70% of the interphase nuclei (Figure 1). The expected deletion of the 3'BCR region (from the FISH results) was not detected by array CGH and BAC probes and only other chromosomal abnormalities were found, including trisomies of chromosomes X, 4, 14, 17, and 21, cryptic deletion of the short arm of chromosome 20 [del (20) (p12.1p12.1)] and submicroscopic amplification of the 22q11.22 region (Figure 1).