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TLX1 Breakapart

Catalogue Numbers
LPH 049-S (5 tests)
LPH 049 (10 tests)

Probe Specification

  • TLX1, 10q24.31, Red
  • TLX1, 10q24.31, Green

The TLX1 product consists of a 179kb probe, labelled in red, located centromeric to the TLX1 gene, including the KAZALD1 gene and the D10S1629 marker and a green probe covering a 124kb region located telomeric to the gene, including the LBX1 gene and the RH92279 marker.

Probe Information

The TLX1 (T-cell leukemia homeobox 1) gene at 10q24 is aberrantly expressed in 30% of adult and 5-10% of childhood T-cell acute lymphoblastic leukaemia (T-ALL)1,2.

Dysregulation of gene transcription is a feature of all acute leukaemias. In T-cell neoplasms, this is brought about by altered expression of normal transcription factor proteins, often as a consequence of chromosomal rearrangements placing these genes into close proximity of the promoter and enhancer elements of the TCR genes: TRA and TRD at 14q11.2, TRB at 7q34 and TRG at 7p143,4.

Murine studies show that expression of mouse homologues of TLX1 can immortalise haematopoietic cells in vitro as the first of a potential two-hit mechanism leading to full malignancy2. This work suggests that TLX1 is an oncogene that can become dysregulated via the translocations t(10;14)(q24;q11) or t(7;10)(q35;q24), placing it into close proximity with TRA/D and TRB elements respectively5. Additionally, TLX1 is frequently activated in T-ALL in the absence of an overt genetic rearrangement. T-ALLs with TLX1 expression show a more favourable outcome than other T-ALLs5.

I first came across Cytocell FISH probes in a previous lab I worked in and I was struck by the quality of the products. Since this time, I have been recommending and introducing Cytocell probes across all application areas — now they are the primary FISH probes used in our lab. They have an excellent range of products and their ready-to-use reagent format saves considerable time. As a matter of fact, at a recent conference there was a discussion about the lack of commercial probes for a particular disorder and I was happy to point the participants in the direction of the Cytocell catalogue, which contains the exact probes required. Elizabeth Benner, Medical Technologist at the University of Arizona Health Network 


  1. Riz et al., Oncogene 2005;24:5561-5575
  2. Hawley RG et al., Oncogene 1994;9:1-12
  3. Korsmeyer SJ, Annual Rev Immunol 1992;10:785-807
  4. Gesk et al., Leukemia 2003;17:738-745
  5. Graux et al., Leukemia 2006;20:1496-1510
  6. Arsham, MS., Barch, MJ. and Lawce HJ. (eds.) (2017) The AGT Cytogenetics Laboratory Manual. New Jersey: John Wiley & Sons Inc.
  7. Mascarello JT, Hirsch B, Kearney HM, et al. Section E9 of the American College of Medical Genetics technical standards and guidelines: fluorescence in situ hybridization. Genet Med. 2011;13(7):667-675.
  8. Wiktor AE, Dyke DLV, Stupca PJ, Ketterling RP, Thorland EC, Shearer BM, Fink SR, Stockero KJ, Majorowicz JR, Dewald GW. Preclinical validation of fluorescence in situ hybridization assays for clinical practice. Genetics in Medicine. 2006;8(1):16–23.

Microscope Images

TLX1 Breakapart magnified
Area of Interest*


This product is intended to be used on Carnoy’s solution (3:1 methanol/acetic acid) fixed haematological samples.

*Disease information supported by the literature and is not a reflection of the intended purpose of this product.