A fusion gene is a genetic anomaly that results from the joining of two or more genes, often due to a chromosomal rearrangement or mutation event. Synonyms for "fusion gene" include chimeric gene, hybrid gene, and fusion transcript. Chimeric gene is a term that is often used to describe a gene created by the merging of two different genes. A hybrid gene is similar and refers to a gene that results from the fusion of two different genes, but it can also refer to a gene that results from the combination of fragments of two genes. Fusion transcript is another synonym for fusion gene and refers to the RNA transcripts that result from the fusion of two different genes. Whatever synony you use they are describing the same thing.