Detection of somatic mutations of the von Hippel-Lindau (VHL) gene in a patient with: (a) 2 or more tumours comprising: (i) 2 or more haemangioblastomas, or (ii) one haemangioblastoma and a tumour of: (A) the adrenal gland; or (B) the kidney; or (C) the pancreas; or (D) the epididymis; and (b) no germline mutations of the VHL gene identified by genetic testing