- Mutations in the SDHB gene are associated with extra-adrenal and/or malignant phaeochromocytomas. Gimenez-Roqueplo, A.P., Favier, J., Rustin, P., Rieubland, C., Crespin, M., Nau, V., Khau Van Kien, P., Corvol, P., Plouin, P.F., Jeunemaitre, X. Cancer Res. (2003)