HUGO Gene Nomenclature Committee (HGNC) recommendations for the designation of gene fusions

Abstract

Gene fusions have been discussed in the scientific literature since they were first detected in cancer cells in the early 1980s. There is currently no standardized way to denote the genes involved in fusions, but in the majority of publications the gene symbols in question are listed either separated by a hyphen (-) or by a forward slash (/). Both types of designation suffer from important shortcomings. HGNC has worked with the scientific community to determine a new, instantly recognizable and unique separator-a double colon (::)-to be used in the description of fusion genes, and advocates its usage in all databases and articles describing gene fusions.

Fig. 1. The chromosomal basis of gene fusions.

a Gene fusions may originate through balanced and unbalanced chromosome rearrangements. Balanced changes comprise translocations (the transfer of chromosome segments between chromosomes), insertions (a chromosome segment in a new interstitial position in the same or another chromosome) and inversions (rotation of a chromosome segment by 180°); an example of an unbalanced change is the deletion of an interstitial chromosomal segment. Small arrows indicate breakpoints, and large arrows indicate the resulting rearranged chromosomes. A and B signify affected genes. Note that a reciprocal gene fusion may be generated on the partner derivative chromosome as a result of a reciprocal translocation, but this is not shown. b Both balanced and unbalanced aberrations may lead to the deregulation of either gene A or gene B by the juxtaposition of the coding sequences with the regulatory sequences of the other gene, or to the creation of a chimeric gene through the fusion of parts of both genes.