Dysregulation of normal transcription is a feature of all types of acute leukaemia. In T-ALL, this is brought about by altered expression of normal transcription factor proteins, which is in contrast with AML and B-ALL, where chimaeric proteins are expressed and provide the drivers for the malignancy.
T-ALL composes around 12-15% of childhood ALL1. In about 30% of these cases, chromosomal rearrangements involving the T-cell receptor genes TRA@ (TCRA), TRB@ (TCRB), TRG@ (TCRG) and TRD@ (TCRD) have been described2. It has been suggested that a number of developmentally important transcription factor genes are dysregulated as a result of being brought into close proximity with the promoter and enhancer elements of one of these T-cell receptor genes3. These can be more clearly demonstrated by FISH than by using conventional cytogenetics4.
The TCRAD complex, on chromosome 14q11.2 has been shown to be involved in a number of different translocations in T-ALL. These include the t(10;14)(q24;q11) involving TLX1 (HOX11); the t(1;14)(p32;q11) involving TAL1; the t(11;14)(p15;q11) involving LMO1 and the t(11;14)(p13;q11) involving LMO2. The relative frequencies for these rearrangements in children have been estimated to be 7, 3, 2 and 3% respectively5.
1. Schneider NR et al., Blood 2000;96:2543-9
2. Secker-Walker LM, Chromosomes and Genes in Acute Lymphoblastic Leukaemia. New York: Chapman and Hall 1997
3. Raimondi SC. T-lineage acute lymphoblastic leukemia (T-ALL) Atlas Genet Cytogenet Oncol Haematol. May 2007
4. Gesk S et al., Leukemia 2003;17:738-45
5. Graux C et al., Leukemia 2006;20:1496-510
- 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.