Cancer is a collection of diseases caused by a wide range of molecular lesions (or mutations). One important class of mutation, called gene fusions, is a common cause of many cancers. Fusion genes form during transcription by one of three mechanisms:
- • translocation,
- • gene deletion, or
- • chromosomal inversion.
Many gene fusions form without having a noticeable effect on human function. However, several gene fusions have been identified that lead to cancer. These cancer-causing gene fusions are referred to as “driver mutations.” One example of a gene fusion is the TMPRSS2:ERGa fusion gene which is found in approximately 50% of prostate cancers. Figure 1 (below) depicts how the TMPRSS2:ERGa fusion is formed from the TMPRSS2 and ERG genes.
Figure 1: Formation of the TMPRSS2:ERGa gene fusion. ( Science. 2005 Oct 28;310(5748):644-8.)