Fusion Genes

Synonyms

Chimeric genes; Chimeric oncogenes; Fusion oncogenes; Hybrid genes

Definition

A hybrid gene created by joining portions of two different genes (to produce a new protein) or by joining a gene to a different promoter (to alter or deregulate a gene transcription).

Characteristics

A wide variety of recurrent molecular alterations has been associated with cancer including polymorphisms, changes in gene copy number (amplifications and deletions), point mutations, epigenetic modifications, and gene fusions due to structural chromosomal rearrangements, such as translocations and less frequently inversions. As for these last ones, the genes located at the breakpoints of the rearrangement may be structurally changed with dramatic effects on their products. Molecularly, two events of structural aberrations can be generated: “promoter swapping” (the exchange of promoter control regions) or fusion gene.

In detail (Fig. 1a), “promoter swapping” occurs when the regulatory elements of a gene...