VHL and hemangioblastoma: Both the Y98H and Y112H VHL mutations are classically associated with VHL Type 2a disease with a high penetrance of pheochromocytoma, but while the Y112H mutation appears to result in hemangioma/hemangioblastoma in only 20% of cases, the Y98H mutation displays a greater penetrance at ~50% (Brauch et al., 1995; Chen et al., 1996).