VHL and renal cell carcinoma: Whilst all the centres recognised that false negative VHL gene testing was more likely in patients with early onset haemangioblastomas than those at an older age, both because the average age at diagnosis is younger in VHL disease than in sporadic cases and because other manifestations of VHL disease (e.g., RCC and visceral cysts) will be more penetrant in older patients, the age at which follow-up continued varied from age <40 to 60 years.