Exploring the association of succinate dehydrogenase complex mutations with lymphoid malignancies.

The succinate dehydrogenase (SDH) complex exerts a fundamental role in mitochondrial cellular respiration and mutations in its encoding genes (SDHA, SDHB, SDHC, SDHD, collectively referred to as SDHx) lead to a number of inherited endocrine cancer predisposition syndromes, including familial paraganglioma/pheochromocytoma. Recent studies suggest a possible role for the SDH complex and other mitochondrial enzymes in the pathogenesis of hematological malignancy. Our aim was to search and identify pedigrees of patients affected by germline SHDx mutations treated at our institution for endocrine and other tumors, and seek to identify cases of hematological malignancy. We also analyzed cancer genome databases for reported cases of SDHx mutations outside of endocrine neoplasms. We report of two unrelated pedigrees carrying SDHx mutations with members affected by lymphomas. Sequencing data revealed one case of chronic lymphocytic leukemia with a SDHB mutation. This novel set of observations demonstrates the need for collaborative databases of patients with endocrine cancers with SDHx mutations, and the investigation of their role in hematological (lymphoid) malignancy.