Genetic Study to Identify Gene Mutations in Participants Previously Enrolled in Clinical Trial NCI-99-C-0053 Who Have Von Hippel-Lindau Syndrome or Are at Risk for Von Hippel-Lindau Syndrome

RATIONALE: The identification of gene mutations in individuals who have or are at risk for von Hippel-Lindau syndrome may allow doctors to better determine the genetic processes involved in the development of cancer. PURPOSE: This genetic study is finding gene mutations in participants with von Hippel-Lindau syndrome or who are at risk for developing von Hippel-Lindau syndrome.