A chromosomal translocation is a type of rearrangement between two chromosomes (usually nonhomologous) that involves breakage of each chromosome at a specific point called breakpoint, followed by fusion of the fragments generated by these breaks. A causative role has been demonstrated for some chromosomal translocations in various cancer types.
Instability of the genome, chromosomal instability in particular, is one of the hallmarks of cancer. Therefore, chromosomal rearrangements are very common in cancer cells. A frequent type of rearrangement is the translocation of genomic fragments between different chromosomal regions. The simplest case is a reciprocal translocation between two chromosomes, but translocations can also involve three or more chromosomes. If no genetic material is lost in the process, translocations are said to be “balanced.” A well-known example of a reciprocal chromosomal translocation in cancer is the t(9;22) implicating the ABL1gene...