SDHD and pheochromocytoma: Germline mutations in SDHB and SDHD, in addition to causing phaeochromocytoma, may also predispose to the development of head and neck paragangliomas (most commonly carotid body tumours) (Baysal et al, 2000; Gimm et al 2000, Astuti et al, 2001a, 2001b, 2003; Gimenez-Roqueplo et al, 2002; Neumann et al, 2002, Benn et al, 2003; Leube et al, 2004).