Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0007095 (carcinoid)
 6,990 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Familial neuroendocrine tumors are reviewed. The most dramatic advances have been in the application of molecular genetic techniques to define the affected genes and to develop predictive testing for patients with multiple endocrine neoplasia syndromes. Germline mutations at specific loci of the RET proto-oncogene have been demonstrated in patients with multiple endocrine neoplasia types IIA, IIB, and familial medullary thyroid carcinoma not associated with multiple endocrine neoplasia. This has led to direct DNA testing for these mutations in patients at risk for these syndromes. The approach to predictive testing, diagnosis, and early treatment of these patients is discussed as a model for the approach to hereditary cancers. Linkage testing with DNA markers is still required for patients with multiple endocrine neoplasia type I because the responsible gene has not yet been isolated. Efforts to clarify the etiologies of other familial neuroendocrine tumors not associated with multiple endocrine neoplasia continue. Familial pheochromocytoma, neuroblastoma, and carcinoid also are reviewed. The use of molecular genetic techniques as a powerful tool for the early identification and treatment of susceptible individuals is emphasized.
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PMID:Familial neuroendocrine tumors as a model of hereditary cancer. 909 Apr 93

Multiple RET proto-oncogene transcripts, due to genomic variations and alternate splicing, have been described. To investigate endocrine tumor tissue characteristic RET proto-oncogene expression, we performed quantitative RT-PCR, Northern blot and Southern blot analyses of benign and malignant endocrine-derived tissues. We newly describe RET proto-oncogene expression in carcinoid-, gastrinoma- and insulinoma-derived tissue samples. In addition, the presence of a 3'-terminally truncated RET proto-oncogene mRNA variant in benign and malignant thyroid neoplasias, as well as in a pheochromocytoma, an ovarian carcinoma and a medullary thyroid carcinoma, is demonstrated. Southern blot analysis revealed no evidence of gross RET proto-oncogene rearrangements or deletions. As the underlying cause for a bi-allelic TaqI restriction fragment length polymorphism (RFLP), a C (allele 1)/T (allele 2) transition within intron 19, was characterized. This polymorphism is close to a recently described polyadenylation site and lies within a binding site for the nucleic acid binding protein Pbx-1. Screening of healthy subjects and of patients suffering from various endocrine malignancies revealed exclusively allele 1 homozygous and allele 1/allele 2 heterozygous genotypes. Heterozygous genotypes were found in a significantly higher percentage in samples derived from endocrine tumor patients when compared with those from healthy control subjects. Homozygosity for allele 2 was found exclusively in somatic DNA derived from endocrine tumors with high malignant potential. Analysis of DNA derived from varying regions within individual anaplastic thyroid carcinomas revealed an allele 1/allele 2 switch of the RFLP banding pattern, indicating loss of heterozygosity at the RET proto-oncogene locus. In conclusion, our data demonstrate presence of a 5'-terminal RET proto-oncogene transcript in endocrine tissues and reveal a bi-allelic RET proto-oncogene polymorphism. A heterozygous genotype for this polymorphism is found in a considerable number of endocrine tumor patients.
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PMID:A newly identified RET proto-oncogene polymorphism is found in a high number of endocrine tumor patients. 1584 88

The rare association between Von Recklin-ghausen's disease (VRD) and tumours other than in central nervous system is well recognized. However, the concomitance of VRD, a carcinoid of the ampulla of Vater, and a pheochromocytoma has been described very rarely in literature. Furthermore, the possible role of the genes usually involved in multiple endocrine neoplasia (MEN) syndromes, in this association, is unclear. We report the case of a patient affected by VRD and extra-adrenal pheochromocytoma, operated on in the past for a carcinoid of the ampulla of Vater. To determine if genes involved in MEN syndromes might play a role in this particular triad, we investigated the presence of somatic or germline mutations in the RET proto-oncogene and menin gene by non isotopic polymerase chain reaction single stranded conformation polymorphism (PCR-SSCP) and heteroduplex gel electro-phoresis. The results demonstrated that no somatic or germline mutations in the MEN-1 and MEN-2 genes were involved in the pathogenesis of these tumours.
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PMID:Absence of gene mutations in a case of concomitant presence of carcinoid of the ampulla of vater pheochromocytoma and Von Recklinghausen disease. 1710 73