Correlation between the ETV6/CBFA2 (TEL/AMLI) fusion gene and karyotypic abnormalities in children with B-cell precursor acute lymphoblastic leukemia
✍ Scribed by Scott Fears; Christine Vignon; Stefan K. Bohlander; Stephen Smith; Janet D. Rowley; Giuseppina Nucifora
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- English
- Weight
- 766 KB
- Volume
- 17
- Category
- Article
- ISSN
- 1045-2257
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✦ Synopsis
The recently identified EN6ICBFA2 (formerly known as TEUAML I) fusion gene occurs as a result of the t( I2;2 I)(p I2;q22). Initial reports have indicated that the fusion transcript occurs in up to 30% of children diagnosed with B-cell precursor (CD I0 + ,CD I 9 +) acute lymphoblastic leukemia (ALL). In order t o characterize the incidence of the t( I2;21) at both the chromosomal level as well as the RNA transcript level, we have used a combination of classical cytogenetics, reverse transcriptase-polymerase chain reaction (RT-PCR), and fluorescence in situ hybridization (FISH) t o examine the bone marrow of 34 children diagnosed with B-cell precursor ALL. Nine of the 34 patient samples expressed the EN6ICBFA2 transcript. When the results of RT-PCR were compared with the conventional karyotype, the fusion was present in 3 of 10 (33%) with chromosome I 2 abnormalities, none of whom had an obvious t( I2;2 I). The transcript was also detected in 5 of the I 2 (4 I %) bone marrow samples with other abnormalities and in I of I 2 (8%) samples with a normal karyotype. Seven of the 9 RT-PCR positive patient samples were studied with FISH. O f the 7, FISH confirmed the EN6ICBFA2 fusion in 6. One other patient with a 12p abnormality had evidence for the fusion using FISH which was not detected by RT-PCR. Our results not only confirm that the frequency of the t ( 12;21) is unusually high in childhood B-cell precursor ALL, but also that none of the translocations in our series was detected with conventional cytogenetic techniques. Genes Chromosom Cancer 17: 127-135 ( 1 996).