Talk to Neuro Physician on Von Hippel Landau

My father was diagnosed with VHL in 2010, and passed away in 2012 due to Renal Cell carcinoma. His symptoms started with Retinal hemangiomas which was left untreated and doctors had to remove his eye. My sister, 16 years old, was recently diagnosed with retinal hemangiomas and is showing symptoms for VHL. We are looking for a Doctor who has experience dealing with VHL Patients and can guide us where to go from here. We have consulted many Medical Specialists but due to the rarity of the disease, we weren't able to get proper consultation.