SDHB and gastrointestinal stromal tumor: Five individuals (8%) from five families, all of whom received an SDHx variant (4 SDHB, 1 SDHD), had a personal history (2 with a GIST (2 SDHB), 2 with a paraganglioma (1 SDHD, 1 SDHB), and 1 with paragangliomas and renal cell carcinoma (1 SDHB)).