Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:1.3.5.1 (succinate dehydrogenase)
8,177 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Familial paraganglioma is a dominantly inherited disorder characterised by the development of highly vascular tumours in the head and neck. Recently, a relationship between hereditary tumours derived from the autonomic nervous system and germline mutations in the gene encoding succinate dehydrogenase complex subunit D (SDHD) is increasingly a subject of study. Familial paraganglioma syndrome is embryologically related to phaeochromocytoma, another neuroendocrine tumour that shows great aetiological and genetic heterogeneity. Some hereditary phaeochromocytomas may be associated with germline mutations in VHL, RET and NF1 genes in genetic disorders such as von Hippel-Lindau disease (VHL), multiple endocrine neoplasia type 2 (MEN 2) and neurofibromatosis type 1 (NF 1), respectively. However, there are many cases that cannot be explained by mutations in these genes. In this report, we describe two previously unreported mutations in two patients from 25 unrelated kindreds with phaeochromocytoma and/or paraganglioma disorders and with or without familial antecedents: a mutation featuring the change of tryptophan to a termination codon in exon 2, and a 4-bp deletion in exon 4 that results in a truncated protein. We also describe one missense substitution of uncertain significance. The patients had previously tested negative for germline mutations in VHL and RET genes and had not been previously selected. The involvement of SDHD mutations in familial phaeochromocytoma and/or paraganglioma predisposition is of considerable interest since other studies have shown these alterations to be associated with highly expressed angiogenic factors.
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PMID:Identification of novel SDHD mutations in patients with phaeochromocytoma and/or paraganglioma. 1211 39

Approximately 10% of catecholamine-secreting tumors are malignant, and 10% are familial. These tumors have been associated with several hereditary syndromes, including multiple endocrine neoplasia type 2, von Hippel-Lindau syndrome, neurofibromatosis type 1, and familial paraganglioma. Mutations in succinate dehydrogenase (SDH) subunit genes have been identified in some kindreds with catecholamine-secreting tumors. In 1972 at the Mayo Clinic, a metastatic catecholamine-secreting paraganglioma was diagnosed in a 32-yr-old man. In 1979, 7 yr after the initial surgical treatment, a lytic metastasis to the left femur was found and was treated with local external radiotherapy. Locally metastatic abdominal catecholamine-secreting paragangliomas were diagnosed in the patient's 27-yr-old son. Analyses of the VHL, RET, SDHD, and SDHC genes revealed no mutations. However, a missense point mutation was detected in the SDHB gene: c.725G-->A in exon 7, which alters a conserved arginine at amino acid position 242 to a histidine (R242H). Sequencing of the SDHB gene in the tumors did not reveal any somatic mutations or loss of heterozygosity of the remaining allele. Thirty years after the initial diagnosis, the father is one of the longest living survivors of malignant catecholamine-secreting paraganglioma. Our findings indicate that mutations in SDHB may be associated with metastatic, yet clinically indolent, abdominal paraganglioma in some families.
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PMID:Familial malignant catecholamine-secreting paraganglioma with prolonged survival associated with mutation in the succinate dehydrogenase B gene. 1221 55

Phaeochromocytomas are neoplasias of neural crest origin arising from the adrenal medulla. Extra-adrenal phaeochromocytomas occur and may be referred to as paragangliomas, although this term is also used to describe vascular head and neck tumours, which most commonly develop at the carotid bifurcation. Historically, genetic factors have been implicated in up to 10% of phaeochromocytoma cases, but recent data suggest that germline mutations may be detected in approximately 25% of unselected cases. The most frequent causes of phaeochromocytoma susceptibility are von Hippel-Lindau disease (VHL), multiple endocrine neoplasia type 2 (MEN 2), the newly delineated phaeochromocytoma-paraganglioma syndrome and, less commonly, neurofibromatosis type 1. Germline mutations in three of the succinate dehydrogenase (SDH, mitochondrial complex II) subunits (SDHD, SDHB and SDHC) cause susceptibility to head and neck paragangliomas, and may be found in approximately 20% of unselected patients. In addition, germline SDHD and SDHB mutations may cause phaeochromocytoma susceptibility with or without associated head and neck paragangliomas. Recent studies suggest that germline SDHD and SDHB mutations are an important cause of familial and isolated phaeochromocytoma. The mechanism by which SDH subunit mutations predispose to phaeochromocytomas has not been defined in detail, but dysregulation of hypoxia-responsive genes and impairment of mitochondria-mediated apoptosis have both been suggested.
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PMID:The pressure rises: update on the genetics of phaeochromocytoma. 1235 69

We review genetic aspects and recent advances in our understanding of the molecular pathogenesis of familial chromaffin cell tumors (pheochromocytoma, paraganglioma). About 10 percent of pheochromocytomas are familial and occur as part of multiple endocrine neoplasia type 2 (MEN 2), von Hippel-Lindau (VHL) disease, and neurofibromatosis type 1 (NF 1). A subset of paragangliomas, tumors that can also produce and secrete catecholamines, are also familial and occur in patients with germline mutations in genes that encode subunits of the mitochondrial complex II. The precise molecular mechanisms underlying the pathogenesis of chromaffin cell tumors remain widely unknown, although recent studies in hereditary tumors help elucidate their development. In MEN 2, overrepresentation of mutant RET in selected adrenomedullary cells may be an important mechanism in initiating the formation of a pheochromocytoma. In VHL disease, pheochromocytoma development appears to occur according to Knudson's two-hit model, a VHL germline mutation and wildtype allelic deletion. Tumorigenesis of NF1-associated pheochromocytomas remains unknown, as does tumor formation (i.e., carotid body tumor) in patients with germline mutations in SDHB, SDHC, and SDHD, genes that encode subunits of the mitochondrial complex II, the smallest complex in the respiratory chain. Many genetic alterations have been found in sporadic chromaffin cell tumors. However, at present such genetic changes are difficult to place into context with regard to tumor formation and progression.
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PMID:New insights into the genetics of familial chromaffin cell tumors. 1238 38

Pheochromocytomas and paragangliomas are tumors of the autonomic nervous system; pheochromocytomas are tumors of the adrenal medulla, and paragangliomas are extra-adrenal tumors arising from either the sympathetic nervous system or parasympathetic ganglia. It has previously been estimated that approximately 10%-15% of pheochromocytomas are due to hereditary causes. However, our increased understanding of the three hereditary syndromes (neurofibromatosis 1, multiple endocrine neoplasia type 2, and von Hippel-Lindau syndrome) in which pheochromocytoma is found and the recent discovery that mutations in genes in the succinate dehydrogenase family (SDHB and SDHD) predispose to pheochromocytoma have necessitated a re-evaluation of the genetic basis of pheochromocytoma. These studies indicate that the frequency of germline mutations associated with isolated pheochromocytoma is higher than previously estimated, with both hospital-based series and a large population-based series indicating that the frequency of germline mutations in RET, VHL, SDHB, and SDHD taken together approximates 20%. In all patients with pheochromocytoma, including those with known hereditary syndrome or a positive family history, the frequency of germline mutations in these four genes together approaches 30%. Given the frequency of germline mutations, consideration should be given to genetic counseling for all patients with pheochromocytoma and is particularly important for individuals with a positive family history, multifocal disease, or a diagnosis before age 50. Identification of patients with hereditary pheochromocytoma is important because it can guide medical management in mutation-positive patients and their families. This review provides an overview of the known genetic syndromes that are commonly associated with pheochromocytoma, examines recent data on the association of germline mutations in the succinate dehydrogenase gene family with pheochromocytoma, and suggests guidelines for the genetic evaluation of pheochromocytoma patients.
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PMID:Pheochromocytoma: the expanding genetic differential diagnosis. 1292 44

Endocrine surgeons should maintain a high index of suspicion when patients are diagnosed with clinical signs or symptoms of parathyroid carcinoma. Although rare, the best chance for cure of these patients is at the time of the initial operation. Surgical resection of recurrent disease can provide effective palliation and can sometimes be assisted using gamma-probe directed dissection of sestamibi-labeled tumor tissue. Treatment of hyperparathyroidism in the setting of multiple endocrine neoplasia type 1 (MEN-1), particularly in the reoperative setting, can be aided by using the rapid intraoperative parathyroid hormone assay to judge the adequacy of parathyroid debulking. In addition, in selected cases, the gamma probe can assist in identifying the location of ectopic or autografted sestamibi-labeled parathyroid tissue. Patients with incidental adrenal masses rarely require fine needle aspiration to exclude metastatic cancer. Fine needle aspiration, if performed, should never precede hormone evaluation to exclude pheochromocytoma. Patients who are diagnosed with incidental adrenal masses in the setting of a prior or concurrent cancer diagnosis are equally likely to have a primary adrenal mass as they would be to have metastatic cancer in the adrenal gland. Pheochromocytomas occasionally develop in patients with MEN-1. In suspicious cases, molecular identification of an MEN-1 mutation can be used to confirm the diagnosis. Preoperative hormone evaluation of a patient with an adrenal incidentaloma should include evaluation for subclinical Cushing's syndrome through an overnight 1-mg dexamethasone suppression test. Identification of this condition allows for safe peri- and postoperative steroid hormone replacement, with very slow withdrawal of exogenous steroids to allow the opposite adrenal gland to recover and avoid postoperative Addisonian crisis. Paragangliomas are more commonly multifocal and malignant compared to pheochromocytomas. Evaluation of patients with paragangliomas should include radiographic staging for multifocality and metastatic disease, and postoperative hormone and radiographic follow-up evaluation should be performed. Consideration should be given to genetic testing for von Hippel-Lindau and succinate dehydrogenase mutations. Surgical treatment of rare functioning pancreatic and duodenal endocrine tumors, such as metastatic sporadic insulinoma and MEN-1-associated gastrinoma, can provide effective palliation. Surgical treatment should be integrated into a comprehensive treatment scheme that recognizes the natural history of the disease and incorporates appropriate adjunctive therapies and follow-up strategies.
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PMID:Unusual functioning endocrine tumors. 1523 9

Pheochromocytoma is a neuroendocrine tumor associated with a variety of genetic disorders, which include von Hippel-Lindau disease (VHL), multiple endocrine neoplasia type 2 (MEN 2), neurofibromatosis type 1, hereditary paraganglioma, and succinate dehydrogenase gene-related tumors. Previous studies of VHL-associated and MEN 2-associated pheochromocytomas suggest morphological, biochemical, and clinical differences exist among the tumors, but the process by which they develop remains unclear. Studies in other VHL-associated tumors suggest that VHL gene deficiency causes coexpression of erythropoietin (Epo) and its receptor (Epo-R), which facilitates tumor growth. The objective of this study was to understand the different process of tumorigenesis for VHL and MEN 2-associated pheochromocytomas. Ten pheochromocytomas (VHL patients n = 5, MEN 2 patients n = 5) were examined for the presence or absence of Epo and Epo-R using Western blot, immunohistochemistry, and RT-PCR analyses. Coexpression of Epo and Epo-R was found in all five VHL-associated pheochromocytomas; in contrast, expression of Epo-R, but not Epo, was documented in all five MEN 2-associated pheochromocytomas. Expression of Epo appears to be a result of VHL gene deficiency, possibly through activation of the hypoxia inducible factor-1 pathway, whereas Epo-R is an embryonal marker whose sustained expression in both VHL- and MEN 2-associated pheochromocytomas reflects an arrest or defect in development. These findings suggest an alternative process of tumorigenesis in VHL- and MEN 2-associated pheochromocytomas and implicate Epo as a clinical biomarker to differentiate these tumors.
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PMID:Differential expression of erythropoietin and its receptor in von hippel-lindau-associated and multiple endocrine neoplasia type 2-associated pheochromocytomas. 1576 89

Phaeochromocytoma is a neural-crest-derived tumour that may be a feature of several familial cancer syndromes including von Hippel-Lindau (VHL) disease, multiple endocrine neoplasia type 2 (MEN 2), neurofibromatosis type 1 (NF1) and germline succinate dehydrogenase subunit (SDHB and SDHD) mutations. However the somatic genetic and epigenetic events that occur in phaeochromocytoma tumourigenesis are not well defined. Epigenetic events including de novo promoter methylation of tumour-suppressor genes are frequent in many human neoplasms. As neuroblastoma and phaeochromocytoma are both neural-crest-derived tumours, we postulated that some epigenetic events might be implicated in both tumour types and wished to establish how somatic epigenetic alterations compared in VHL-associated and sporadic phaeochromocytomas. We identified frequent aberrant methylation of HIC1 (82%) and CASP8 (31%) in phaeochromocytoma, but both genes were significantly more methylated in VHL phaeochromocytomas than in sporadic cases. Of four tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) receptors analysed, DR4 was most commonly methylated (41%; compared with DcR2 (26%), DcR1 (23%) and DR5 (10%)). Gene methylation patterns in phaeochromocytoma and neuroblastoma did not differ significantly suggesting overlapping mechanisms of tumourigenesis. We also investigated the role of 11p15.5-imprinted genes in phaeochromocytoma. We found that in 10 sporadic and VHL phaeochromocytomas with 11p15.5 allele loss, the patterns of methylation of 11p15.5-differentially methylated regions were consistent with maternal, rather than, paternal chromosome loss in all cases (P<0.001). This suggests that 11p15.5-imprinted genes may be implicated in the pathogenesis of both familial (germline VHL and SDHD mutations) and sporadic phaeochromocytomas.
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PMID:Epigenetic analysis of HIC1, CASP8, FLIP, TSP1, DCR1, DCR2, DR4, DR5, KvDMR1, H19 and preferential 11p15.5 maternal-allele loss in von Hippel-Lindau and sporadic phaeochromocytomas. 1578 47

Pheochromocytoma are tumors derived from chromaffin cells that secrete catecholamines. These catecholamines may lead to increased blood pressure and even death. Historically, pheochromocytoma have been described as 10 tumor, i.e. about 10 were believed to be malignant, 10 were found to be extra-adrenal, and 10 were meant to be bilateral. Also, about 10 were considered to be hereditary. In these instances, they were most often part of either the multiple endocrine neoplasia type 2 (MEN 2) syndrome or the von Hippel-Lindau (VHL) disease. The genes (RET and VHL) involved have been known for several years and their function is the subject of ongoing investigation. Very recently, several genes (SDHD, SDHB, and SDHC) that belong to the mitochondrial complex II have been identified to be involved in the so-called pheochromocytoma-paraganglioma syndrome. Only SDHD and SDHB have so far been implicated in the pathogenesis of pheochromocytoma.
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PMID:Pheochromocytoma-associated syndromes: genes, proteins and functions of RET, VHL and SDHx. 1588 6

Pheochromocytoma and paraganglioma are tumors of the autonomic nervous system. Various syndromes have been found to be associated with the development of pheochromocytomas and paragangliomas: multiple endocrine neoplasia type 2 (MEN 2, susceptibility gene: RET), von Hippel-Lindau disease (VHL, susceptibility gene: VHL), neurofibromatosis 1 (NF 1), and paraganglioma syndromes type 1, 3, and 4 (susceptibility genes: succinate dehydrogenase gene, SDH, subunits D, C and B, respectively). Prevalence and clinical features of pheochromocytomas and paragangliomas are different for each of these syndromes. Mutational analysis of the susceptibility genes of these syndromes in patients presenting with pheochromocytoma or paraganglioma may help to judge the risks of multifocality of the tumor as well as development of malignant pheochromocytoma or of other malignant tumors. Here we review the recent progress in clinical characterization and genetic testing for these syndromes. Based on tumor characteristics and prevalence data we give recommendations for an efficient genetic testing procedure in patients presenting with pheochromocytomas and paragangliomas.
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PMID:Genetic testing for pheochromocytoma-associated syndromes. 1598 78


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