EXOSC8 and hereditary disease: However, mutations in multiple genes that encode structural subunits of the RNA exosome termed exosomopathies, including two cap subunit genes, EXOSC3 [6, 21, 37–39] and EXOSC2 [5], and two core subunit genes, EXOSC8 [3] and EXOSC9 [40, 41], have now been linked to genetic diseases with a variety of clinical presentations reported.