Context: Pheochromocytoma-paraganglioma syndrome is caused by mutations in SDHB, SDHC, and SDHD, encoding subunits of succinate dehydrogenase (SDH), and in SDHAF2, required for flavination of SDHA. A recent report described a patient with an abdominal paraganglioma, immunohistochemically negative for SDHA, and identified a causal germline mutation in SDHA.
Objective: In this study, we evaluated the significance of SDHA immunohistochemistry in the identification of new patients with SDHA mutations.
Setting: This study was performed in the Erasmus Medical Center in Rotterdam (The Netherlands) and the Université Paris Descartes in Paris (France).
Methods: We investigated 316 pheochromocytomas and paragangliomas for SDHA expression. Sequence analysis of SDHA was performed on all tumors that were immunohistochemically negative for SDHA and on a subset of tumors immunohistochemically positive for SDHA.
Results: Six tumors were immunohistochemically negative for SDHA. Four tumors from Dutch patients showed a germline c.91C → T SDHA gene mutation (p.Arg31X). Another tumor (from France) carried a germline SDHA missense mutation c.1753C → T (p.Arg585Trp). Loss of the wild-type SDHA allele was confirmed by loss of heterozygosity analysis. Sequence analysis of 35 SDHA immunohistochemically positive tumors did not reveal additional SDHA mutations.
Conclusions: Our results demonstrate that SDHA immunohistochemistry on paraffin-embedded tumors can reveal the presence of SDHA germline mutations and allowed the identification of SDHA-related tumors in at least 3% of patients affected by apparently sporadic (para)sympathetic paragangliomas and pheochromocytomas.
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http://dx.doi.org/10.1210/jc.2011-1043 | DOI Listing |
Elife
December 2024
National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, United States.
Mitochondrial biogenesis requires the expression of genes encoded by both the nuclear and mitochondrial genomes. However, aside from a handful transcription factors regulating specific subsets of mitochondrial genes, the overall architecture of the transcriptional control of mitochondrial biogenesis remains to be elucidated. The mechanisms coordinating these two genomes are largely unknown.
View Article and Find Full Text PDFCancer Metab
December 2024
Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine and Science, 200 First St. SW, Rochester, MN, 55905, USA.
Heterozygosity for loss-of-function alleles of the genes encoding the four subunits of succinate dehydrogenase (SDHA, SDHB, SDHC, SDHD), as well as the SDHAF2 assembly factor predispose affected individuals to pheochromocytoma and paraganglioma (PPGL), two rare neuroendocrine tumors that arise from neural crest-derived paraganglia. Tumorigenesis results from loss of the remaining functional SDHx gene copy, leading to a cell with no functional SDH and a defective tricarboxylic acid (TCA) cycle. It is believed that the subsequent accumulation of succinate competitively inhibits multiple dioxygenase enzymes that normally suppress hypoxic signaling and demethylate histones and DNA, ultimately leading to increased expression of genes involved in angiogenesis and cell proliferation.
View Article and Find Full Text PDFJCO Precis Oncol
December 2024
Divison of Cancer Genetics and Prevention, Dana-Farber Cancer Institute, Boston, MA.
Purpose: In patients with a variety of malignancies undergoing multigene panel testing (MGPT), we examined the frequency of a pathogenic/likely pathogenic variant (PV) that would not have been predicted on the basis of the patient's personal and family history of cancer.
Methods: This is a retrospective review of patients with cancer ascertained from a single academic cancer center who underwent broad-based MGPT of ≥20 cancer predisposition genes not selected on the basis of personal or family cancer history from 2015 to 2021. Low-penetrance variants and recessive inheritance genes were excluded.
Oncol Lett
February 2025
Department of Pathology, Hubei Cancer Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430079, P.R. China.
Succinate dehydrogenase (SDH)-deficient renal cell carcinoma (RCC) is a rare subtype of RCC characterized by the presence of a germline mutation in one of the four subunits of the SDH enzyme complex (SDHA, SDHB, SDHC and SDHD). Together with a somatic second hit, these variants lead to the loss of function of the SDH complex. SDH-deficient RCC associated with SDHA mutation is a rare condition; to the best of our knowledge, there have been only four patients reported in the literature.
View Article and Find Full Text PDFJ Endocrinol Invest
December 2024
Department of Urology, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, 410008, Hunan, China.
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