SDHB and neurofibromatosis type 1: The most common hereditary syndromes are those derived from germline mutations in genes encoding the different subunits of SDH (type 1: SDHD; type 2: SDHAF2; type 3: SDHC; type 4: SDHB; type 5: SDHA; including Carney-Stratakis syndrome) (15–20%), Von Hippel-Lindau (VHL) syndrome due to mutations in the VHL gene (9%), multiple endocrine neoplasia-2 (MEN2) syndrome due to mutations in the RET proto-oncogene (5%) and neurofibromatosis type 1 (NF-1) syndrome due to mutations in the NF1 gene (2%).