RET and neurofibromatosis type 1: The genes that have previously been associated with paraganglioma in humans are NF1 (causing neurofibromatosis type 1), RET (endocrine neoplasms multiple types 2a and 2b) (73), VHL (von Hippel–Lindau syndrome), SDHB, SDHC, and SDHAF2 neurofibromatosis type 1 appears because of a mutation in the NF1 gene located on chromosome 17q11.