A single split-signal FISH probe set allows detection of TAL1 translocations as well as SIL-TAL1 fusion genes in a single test.
About 30% of T cell acute lymphoblastic leukemias (T-ALL) carry TAL1 gene aberrations. In the majority of cases (approximately 25%), this concerns a submicroscopic deletion of approximately 90 kb in chromosome region 1p32, which deletes the coding regions of the SIL gene and the untranslated region of the TAL1 gene, thereby placing the TAL1 gene under control of the SIL promoter region. Translocation (1;14)(p32;q11) involving the TAL1 gene occurs at a much lower frequency (3%), whereas some other rare variant translocations have been described as well. In this study we developed a set of TAL1 FISH probes based on the split-signal FISH principle that enables detection of both types of TAL1 gene aberrations in single test. For this purpose, one probe was designed downstream of the TAL1 gene (TAL1-D) and the second probe in the region upstream of the TAL1 gene, partly covering the SIL gene (SIL-U). We show that this split-signal FISH probe set allows reliable detection of the unaffected SIL-TAL1 gene region with a fusion signal, SIL-TAL1 fusion genes with loss of the SIL-U signal, and TAL1 gene translocations with a split-signal, independent of the involved partner gene.
van der Burg
M
M
Dept of Immunology, Erasmus University Rotterdam/University Hospital Rotterdam, The Netherlands.
Smit
B
B
Brinkhof
B
B
Barendregt
B H
BH
Verschuren
M C M
MC
Dib
M
M
Beverloo
H B
HB
van Dongen
J J M
JJ
Langerak
A W
AW
D001426:Bacterial Proteins / Q000235:genetics*; D051792:Basic Helix-Loop-Helix Proteins; D019457:Chromosome Breakage; D002878:Chromosomes, Human, Pair 1 / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics*; D017353:Gene Deletion; D015723:Gene Library; D018257:Helix-Loop-Helix Motifs; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D015459:Leukemia-Lymphoma, Adult T-Cell / Q000235:genetics* / Q000276:immunology; D015514:Oncogene Proteins, Fusion / Q000235:genetics; D016133:Polymerase Chain Reaction; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics*; D011518:Proto-Oncogene Proteins; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D000073942:T-Cell Acute Lymphocytic Leukemia Protein 1; D014157:Transcription Factors / Q000235:genetics; D014178:Translocation, Genetic
D001426:Bacterial Proteins; D051792:Basic Helix-Loop-Helix Proteins; D004268:DNA-Binding Proteins; D015514:Oncogene Proteins, Fusion; D011518:Proto-Oncogene Proteins; D000073942:T-Cell Acute Lymphocytic Leukemia Protein 1; D014157:Transcription Factors; C067143:TAL1 protein, human