ETV6 / RUNX1 t(12;21) Fusion probe hybridized to patient material showing t(12;21)translocation (2RG1R1G). Material kindly provided by Dr. Balogh, Budapest.
The t(12;21), a cryptic translocation rarely observed by conventional cytogenetics, was first identified by fluorescence in situ hybridization (FISH). In ALL blasts, this translocation fuses the 5' part of the ETV6 (previously known as TEL) gene with almost the entire RUNX1 (previously known as AML) (CBFA2) gene, producing the chimeric transcript ETV6-CBFA2. The t(12;21) (p13;q22) has also been identified as the most frequent chromosomal abnormality in childhood ALL, affecting 20% to 25% of B-lineage cases. The ETV6/RUNX1 t(12;21) specific FISH probe is optimized to detect the reciprocal translocation t(12;21) (p13;q22) in a dual-color, dual-fusion assay.
References: Romana et al, 1995, Blood, 85; 3662-3670.