VHL and hemangioma of retina: The level of mutation detection obtained by molecular genetic testing of the VHL makes it possibleto effectively rule out VHL syndrome with a high degree of certainty inindividuals with isolated hemangioblastoma, retinal angioma,or clear cell RCC, who have no detectable VHL disease-causing germline mutation; somatic mosaicism for a VHL gene mutation still needs to be considered insuch individuals.