Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.3.5.1 (succinate dehydrogenase)
 8,177 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hereditary paraganglioma (PGL) is characterized by the development of slow-growing and vascularized tumors in the paraganglionic system. PGL is caused by germ line heterozygous inactivating mutations in the SDHB (PGL4), SDHC (PGL3), or SDHD (PGL1) genes, which encode three of the four subunits of mitochondrial complex II (succinate dehydrogenase; SDH). Common tumor sites include the carotid body in the neck and paraganglia in the abdomen. The risk of tumor development associated with SDHD mutations is determined by the sex of the transmitting parent, because only a paternal transmission leads to tumorigenesis in the progeny. This transmission pattern suggests operation of genomic imprinting on the SDHD gene. There is also evidence that the risk of tumor development increases at higher altitudes among SDHD mutation carriers. Accordingly, the increased prevalence of SDHD mutations in the Netherlands, attributable to multiple founder mutations, has been explained in part by the low altitudes in this country, which presumably reduce gene penetrance and relax the natural selection. Thus, PGL caused by SDHD mutations represents an unusual example of an inherited monogenic tumor syndrome because the risk of tumorigenesis shows an absolute dependence on the sex of the transmitting parent and may be modified by a ubiquitous environmental factor.
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PMID:Genomic imprinting and environment in hereditary paraganglioma. 1526 76

Paragangliomas (PGLs) derive from either sympathetic chromaffin tissue in adrenal and extra-adrenal abdominal or thoracic locations, or from parasympathetic tissue of the head and neck. Mutations of nuclear genes encoding subunits B, C, and D of the mitochondrial enzyme succinate dehydrogenase (SDHB 1p35-p36.1, SDHC 1q21, SDHD 11q23) give rise to hereditary PGL syndromes PGL4, PGL3, and PGL1 respectively. The susceptibility gene for PGL2 on 11q13.1 remains unidentified. Mitochondrial dysfunction due to SDHx mutations have been linked to tumorigenesis by upregulation of hypoxic and angiogenesis pathways, apoptosis resistance and developmental culling of neuronal precursor cells. SDHB-, SDHC-, and SDHD-associated PGLs give rise to more or less distinct clinical phenotypes. SDHB mutations mainly predispose to extra-adrenal, and to a lesser extent, adrenal PGLs, with a high malignant potential, but also head and neck paragangliomas (HNPGL). SDHD mutations are typically associated with multifocal HNPGL and usually benign adrenal and extra-adrenal PGLs. SDHC mutations are a rare cause of mainly HNPGL. Most abdominal and thoracic SDHB-PGLs hypersecrete either norepinephrine or norepinephrine and dopamine. However, only some hypersecrete dopamine, are biochemically silent. The biochemical phenotype of SDHD-PGL has not been systematically studied. For the localization of PGL, several positron emission tomography (PET) tracers are available. Metastatic SDHB-PGL is the best localized by [(18)F]-fluorodeoxyglucose PET. The identification of SDHx mutations in patients with PGL is warranted for a tailor-made approach to the biochemical diagnosis, imaging, treatment, follow-up, and family screening.
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PMID:Clinical aspects of SDHx-related pheochromocytoma and paraganglioma. 1919 77

Paragangliomas/pheochromocytomas (PGL/PCC) are tumors of the paraganglia. They can occur sporadically, as one sign in a hereditary (tumor) syndrome or as the only manifestation in hereditary PGL/PCC. To date, five forms of hereditary PGL/PCC have been described. They are inherited as autosomal dominant traits and are caused by mutations in genes required for structure and function of complex II of the respiratory chain (succinate-ubiquinone oxidoreductase, succinate dehydrogenase, SDH). Mutations in genes encoding the small subunits of SDH, i.e., SDHD and SDHC, cause PGL1 and PGL3. Mutations in the large subunit genes SDHB, SDHA (currently only one case), and in SDHAF2 cause PGL4, 5, and 2, respectively. This article gives an overview of PGL/PCC in the context of the anatomy and function of paraganglia. It describes SDH, the genes encoding SDH, and provides information on genetic mechanisms in hereditary PGL/PCC. A model is proposed to explain exclusive paternal inheritance and loss of the maternal (putatively imprinted) allele as a prerequisite for tumor formation in PGLs 1 and 2.
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PMID:Pathological mechanisms and parent-of-origin effects in hereditary paraganglioma/pheochromocytoma (PGL/PCC). 2154 62

The etiology and pathogenesis of renal cell carcinoma (RCC) are only partially understood. Key findings in hereditary RCC, which may be site specific or a component of a syndrome, have contributed to our current understanding. Important heritable syndromes of RCC are those associated with pheochromocytoma, especially von Hippel-Lindau disease (VHL) associated with germline VHL mutations, and pheochromocytoma and paraganglioma syndrome (PGL) associated with mutations in one of the four genes (SDHA-D) encoding succinate dehydrogenase. A subset of individuals with SDHB and SDHD germline DNA mutations and variants develop RCC. RCC has never been described as a component of SDHC-associated PGL3. The European-American Pheochromocytoma and Paraganglioma Registry comprises 35 registrants with germline SDHC mutations. A new registrant had carotid body tumor (CBT) and his mother had CBT and bilateral RCC. Blood DNA, paragangliomas, and RCCs were analyzed for mutations and loss-of-heterozygosity (LOH) in/flanking SDHC and VHL. The proband with unilateral CBT had a germline SDHC c.3G>A (p.M1I) mutation. His mutation-positive mother had CBT at age 42, clear cell RCC (ccRCC) at age 68, and papillary RCC (pRCC) at age 69. Both paraganglial tumors showed somatic LOH of the SDHC locus. Both ccRCC and pRCC did not have a somatic SDHC mutation but showed LOH for intragenic and flanking markers of the SDHC locus. LOH was also present for the VHL locus. Our findings suggest that RCC is a component of PGL3. Biallelic inactivation of the SDHC gene may represent a new pathway of pathogenesis of syndromic and nonsyndromic RCC, perhaps of both clear cell and papillary histologies.
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PMID:Biallelic inactivation of the SDHC gene in renal carcinoma associated with paraganglioma syndrome type 3. 2235 10

The paraganglioma (PGL) syndromes types 1-5 are autosomal dominant disorders characterized by familial predisposition to PGLs, phaeochromocytomas (PCs), renal cell cancers, gastrointestinal stromal tumours and, rarely, pituitary adenomas. Each syndrome is associated with mutation in a gene encoding a particular subunit (or assembly factor) of succinate dehydrogenase (SDHx). The clinical manifestations of these syndromes are protean: patients may present with features of catecholamine excess (including the classic triad of headache, sweating and palpitations), or with symptoms from local tumour mass, or increasingly as an incidental finding on imaging performed for some other purpose. As genetic testing for these syndromes becomes more widespread, presymptomatic diagnosis is also possible, although penetrance of disease in these syndromes is highly variable and tumour development does not clearly follow a predetermined pattern. PGL1 syndrome (SDHD) and PGL2 syndrome (SDHAF2) are notable for high frequency of multifocal tumour development and for parent-of-origin inheritance: disease is almost only ever manifest in subjects inheriting the defective allele from their father. PGL4 syndrome (SDHB) is notable for an increased risk of malignant PGL or PC. PGL3 syndrome (SDHC) and PGL5 syndrome (SDHA) are less common and appear to be associated with lower penetrance of tumour development. Although these syndromes are all associated with SDH deficiency, few genotype-phenotype relationships have yet been established, and indeed it is remarkable that such divergent phenotypes can arise from disruption of a common molecular pathway. This article reviews the clinical presentations of these syndromes, including their component tumours and underlying genetic basis.
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PMID:15 YEARS OF PARAGANGLIOMA: Clinical manifestations of paraganglioma syndromes types 1-5. 2627 2