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Mutations of the RET proto-oncogene are found in the majority of patients with the inherited cancer syndrome multiple endocrine neoplasia type 2 (MEN 2). A minority of cases, however, have no detectable RET mutation and there is considerable phenotypic variation within and among MEN 2 families with the same RET mutation, suggesting a role for other loci in this disease. A candidate for such a gene is glial cell line-derived neurotrophic factor receptor alpha 4 (GFRA4), which encodes a cell surface-bound co-receptor (GFRa4) required for interaction of RET with its ligand persephin. The GFRA4 gene has multiple alternative splices leading to three distinct protein isoforms that are prominently expressed in thyroid. We postulated that mutations of GFRA4 contribute to MEN 2 in the absence of RET mutations or modify the RET mutation phenotype. We screened patients with MEN 2 or MEN 2-like phenotypes, with and without RET mutations, for variants of GFRA4. We identified 10 variants, one of which was over represented in, and two of which were found exclusively in, our patient populations. One of these was a single-base substitution upstream of the GFRa4 coding region, where it may alter gene expression. The second was a 7?bp insertion, which results in a change in reading frame for all three GFRa4 isoforms. This would cause a relative shift in membrane bound and soluble forms of GFRa4, which would significantly alter the formation of RET signalling complexes. Our data suggest a model of wild-type GFRa4 isoform expression that includes both activating and inhibiting co-receptors for RET.Oncogene (2005) 24, 1091-1097. doi:10.1038/sj.onc.1207826 Published online 13 December 2004 [ABSTRACT FROM AUTHOR]

Copyright of Der Pathologe is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Medullary thyroid cancer (MTC) is a rare neuroendocrine tumor that originates from the parafollicular C cells of thyroid gland. Understanding the fundamental pathophysiology of MTC is essential for clinical management. Single-cell RNA sequencing (scRNA-seq) technology is a powerful tool for identifying distinct cell types, offering a new biological foundation for comprehending the MTC ecosystem and developing precise treatment. Methods: Formalin fixed and paraffin-embedded (FFPE) samples of primary and adjacent non-cancerous tissues of three MTC cases were collected, and single-cell transcriptome data of MTC were obtained by using scRNA-seq technology. Annotated cell subpopulations were categorized and functionally enriched by principal component analysis, differential gene expression, and cell clustering analysis, to explore the biological process of tumor evolution that may be involved in each cell subpopulation. The copy number variation (CNV) profile was used to distinguish the malignancy of parafollicular thyroid cells, and the evolutionary trajectories of normal cells and tumor cells were revealed by the proposed time series analysis. The highly expressed genes in each cell subpopulation were analyzed by the FindAllMarker function of Seurat software, and verified by immunohistochemistry and fluorescence in situ hybridization. The prognostic value of specific cell subtypes was validated using large-scale public datasets. Results: A total of 32,544 cells were obtained from the MTC tissue samples and 11,751 cells from the adjacent non-cancerous samples, which were classified into 7 heterogenous subpopulations by using R package of Seurat module. Copy number variations (CNVs) were significantly higher in tumor tissues than in adjacent non-tumor samples, predominantly enriched in subtypes C2 and C4. In addition, the pseudo-time for trajectory analysis suggested that the evolution of MTC tumor cells might begin with the C2 subtype, then transition to the early cancer subgroup C3, and further differentiate into four major malignant cell subpopulations C0, C1, C5 and C6. Survival analysis of a thyroid cancer cohort using the TCGA dataset revealed that high expression of genes linked to the C0 subcluster was correlated with poorer overall survival compared to low expression. Immunohistochemical staining showed that MAP3K4 was highly expressed in MTC tissues compared to adjacent non-cancerous tissues. Fluorescence in situ hybridization also confirmed the amplification of these two genes in MTC samples. Conclusions: By conducting scRNA-seq on FFPE samples, we mapped the single-cell transcriptome of MTC, uncovering the tumor heterogeneity and unique biological features of each cellular subpopulation. The biological roles of identified tumor cell subpopulations such as C0 and C3 subtypes of parafollicular cells suggested the potential to discover new therapeutic targets and biomarkers for MTC, providing valuable insights for future translational and clinical research. [ABSTRACT FROM AUTHOR]

Purpose: Inactivating germline mutations in the RET proto-oncogene are the major genetic cause of Hirschsprung's disease (HD). In some cases, HD can be associated with medullary thyroid carcinoma (MTC) that is commonly caused by activating RET mutations. Methods: The retrospective and prospective genetic analyses of 157 patients with HD operated on between December 1979 and June 2011 were carried out. DNA was isolated from peripheral leukocytes. HD patients and family members were tested for RET mutations by direct sequencing and single-strand conformation polymorphism methods. Results: RET mutations were detected in 16 patients (10%). Association with MTC was found in two families, other eight families had a mutation with potentially high risk of MTC development and four novel mutations were detected. Total colonic aganglionosis was noted to have a high mutation detection rate (40%). Three patients underwent total thyroidectomy (two had clinical manifestation of MTC, one C-cell hyperplasia). Conclusion: Results show the benefit of systematic RET mutation screening in HD patients in order to identify the risk of MTC in the preclinical stage of the disease. All patients should be tested for RET mutations at least in exon 10, and now additionally in exon 11 and 13, as well. [ABSTRACT FROM AUTHOR]

Background: A malignancy of the endocrine system, one of the most common types, is thyroid cancer. It is proven that children who receive radiation treatment for leukemia or lymphoma are at a heightened risk of thyroid cancer due to low-dose radiation exposure throughout childhood. Several factors can increase the risk of thyroid cancer (ThyCa), such as chromosomal and genetic mutations, iodine intake, TSH levels, autoimmune thyroid disorders, estrogen, obesity, lifestyle changes, and environmental contaminants. Objectives: The study aimed to identify a specific gene as an essential candidate for thyroid cancer progression. We might be able to focus on developing a better understanding of how thyroid cancer is inherited. Methods: The review article uses electronic databases such as PubMed, Google Scholar, Ovid MEDLINE, Embase, and Cochrane Central. The most frequently associated genes with thyroid cancer found on PubMed were BAX, XRCC1, XRCC3, XPO5, IL-10, BRAF, RET, and K-RAS. To perform an electronic literature search, genes derived from DisGeNET: a database of gene-disease associations, including PRKAR1A, BRAF, RET, NRAS, and KRAS, are used. Conclusion: Examining the genetics of thyroid cancer explicitly emphasizes the primary genes associated with the pathophysiology of young and older people with thyroid cancer. Developing such gene investigations at the beginning of the thyroid cancer development process can identify better outcomes and the most aggressive thyroid cancers. [ABSTRACT FROM AUTHOR]

Medullary thyroid carcinoma (MTC) is a C-cell-derived epithelial neuroendocrine neoplasm. With the exception of rare examples, most are well-differentiated epithelial neuroendocrine neoplasms (also known as neuroendocrine tumors in the taxonomy of the International Agency for Research on Cancer [IARC] of the World Health Organization [WHO]). This review provides an overview and recent evidence-based data on the molecular genetics, disease risk stratification based on clinicopathologic variables including molecular profiling and histopathologic variables, and targeted molecular therapies in patients with advanced MTC. While MTC is not the only neuroendocrine neoplasm in the thyroid gland, other neuroendocrine neoplasms in the thyroid include intrathyroidal thymic neuroendocrine neoplasms, intrathyroidal parathyroid neoplasms, and primary thyroid paragangliomas as well as metastatic neuroendocrine neoplasms. Therefore, the first responsibility of a pathologist is to distinguish MTC from other mimics using appropriate biomarkers. The second responsibility includes meticulous assessment of the status of angioinvasion (defined as tumor cells invading through a vessel wall and forming tumor-fibrin complexes, or intravascular tumor cells admixed with fibrin/thrombus), tumor necrosis, proliferative rate (mitotic count and Ki67 labeling index), and tumor grade (low- or high-grade) along with the tumor stage and the resection margins. Given the morphologic and proliferative heterogeneity in these neoplasms, an exhaustive sampling is strongly recommended. Routine molecular testing for pathogenic germline RET variants is typically performed in all patients with a diagnosis of MTC; however, multifocal C-cell hyperplasia in association with at least a single focus of MTC and/or multifocal C-cell neoplasia are morphological harbingers of germline RET alterations. It is of interest to assess the status of pathogenic molecular alterations involving genes other than RET like the MET variants in MTC families with no pathogenic germline RET variants. Furthermore, the status of somatic RET alterations should be determined in all advanced/progressive or metastatic diseases, especially when selective RET inhibitor therapy (e.g., selpercatinib or pralsetinib) is considered. While the role of routine SSTR2/5 immunohistochemistry remains to be further clarified, evidence suggests that patients with somatostatin receptor (SSTR)-avid metastatic disease may also benefit from the option of 177Lu-DOTATATE peptide radionuclide receptor therapy. Finally, the authors of this review make a call to support the nomenclature change of MTC to C-cell neuroendocrine neoplasm to align this entity with the IARC/WHO taxonomy since MTCs represent epithelial neuroendocrine neoplasms of endoderm-derived C-cells. [ABSTRACT FROM AUTHOR]

Background: Pituitary tumours are usually benign and relatively common intracranial tumours, with under- and overexpression of pituitary hormones and local mass effects causing considerable morbidity and increased mortality. While most pituitary tumours are sporadic, around 5% of the cases arise in a familial setting, either isolated [familial isolated pituitary adenoma, related to AIP or X-linked acrogigantism], or in a syndromic disorder, such as multiple endocrine neoplasia type 1 or 4, Carney complex, McCune–Albright syndrome, phaeochromocytoma/paraganglioma with pituitary adenoma, DICER1 syndrome, Lynch syndrome, and USP8-related syndrome. Genetically determined pituitary tumours usually present at younger age and show aggressive behaviour, and are often resistant to different treatment modalities. Subject: In this practical summary, we take a practical approach: which genetic syndromes should be considered in case of different presentation, such as tumour type, family history, age of onset and additional clinical features of the patient. Conclusion: The identification of the causative mutation allows genetic and clinical screening of relatives at risk, resulting in earlier diagnosis, a better therapeutic response and ultimately to better long-term outcomes. [ABSTRACT FROM AUTHOR]

Hirschsprung disease (HSCR) is a fairly well understood congenital, genetically based functional obstruction due to the congenital absence of ganglion cells in the distal bowel. However, although over 90% of Hirschsprung cases conform to the normally accepted histological diagnostic criteria, it has become increasingly clear that in addition to HSCR, there is a group of functional disturbances relating to a number of other congenital neurodysplastic conditions causing some degree of gastrointestinal tract malfunction. Although these represent a variety of possibly separate conditions of the enteric nervous system, this spectrum it would appear to be also influenced by similar developmental processes. The term "variant Hirschsprung" is commonly used to describe these conditions, but ganglion cells are mostly present if abnormal in number and distribution. These conditions are a problem group being amongst the most difficult to diagnose and treat with possible practical and legal consequences. The problem appears to be possibly one of definition which has proven difficult in the relative paucity of normal values, especially when correlated to age and gestation. It is the purpose of this paper to review the current position on these conditions and to explore possible shared common pathogenetic and genetic mechanisms. This article explores those conditions where a similar pathogenetic mechanisms to HSCR can be demonstrated (e.g. hypoganglionosis) as well as other neural features, which appear to represent separate conditions possibly linked to certain syndromes. [ABSTRACT FROM AUTHOR]

Medullary thyroid carcinoma (MTC) is a rare form of malignancy, having an intermediate prognosis. Controversies exist regarding the best surgical approach. The aim of the study was to analyze the outcome in a group of patients with MTC, diagnosed and followed up in a single care center. We performed a retrospective analysis of all the patients diagnosed with MTC in the Department of Endocrinology from the County Emergency Hospital Timisoara between 1992 and 2012. The study group included 19 patients, 6 men (31.6 %), mean age 41.2 ± 12.5 years (20-72 years). The preoperative diagnosis was based on the protocol for nodular thyroid disease. Total or near-total thyroidectomy was performed in 10 out of 16 patients who could be operated. Postoperative follow-up included repeated measurements of serum calcitonin and imaging investigations. Nine out of the total of 19 (47.3 %) patients had hereditary forms of MTC. Most of the cases (84.2 %) were submitted to surgery. The median duration of follow-up was 84 months. The pTNM staging indicated that the majority of the patients with hereditary MTC were diagnosed in an earlier stage. Disease remission was achieved in 7 cases (43.8 %). Four patients, all with sporadic forms, died. Survival rates at 1, 5 and 10 years were significantly higher ( p = 0.048) in patients with hereditary MTC. An early diagnosis of MTC allows a better surgical approach and an improved survival rate. We support the general recommendation that modified radical neck dissection is not necessary for all the patients with MTC. [ABSTRACT FROM AUTHOR]

Purpose: This 'consensus statement' aims to summarise the current evidence-based knowledge as to 'timing' and planning the 'extent' of thyroid surgery in terms of an optimal balance between the prevention of thyroid malignancy (involving metastasis) and the risks associated with more extended surgery (permanent hypoparathyroidism, permanent paralysis of the recurrent laryngeal nerve). Surgery 'in time' is influenced by genetic findings and age. Basal (and stimulated) calcitonin levels may individualise the timing and extent of surgery. Materials and methods: The review of English-language studies addressing the management of REarranged during Transfection proto-oncogene mutation carriers including the time, extent of thyroid surgery and results. Evidence is mostly obtained from well-designed, non-experimental descriptive investigations, such as comparative, correlation and case-control studies (level III) with a grading of recommendation B, or from expert committee reports or opinions and/or the clinical experience of respected authorities (level IV) with a grading of recommendation C, respectively. Results: 'Risk level D' includes multiple endocrine neoplasia 2B cases. Thyroidectomy is recommended within the first year of life, preferably as soon as possible, due to the very early transformation of C cell hyperplasia to more aggressive tumours. Calcitonin levels may be less helpful. In patients with codon 634 mutations (risk level C), thyroidectomy between ages 2 and 4 years has been proposed based upon evidence of age-dependent and codon-specific progression of early medullary thyroid cancer. In 'risk level B' (codons 609, 611, 618, 620, 630 and 804), tandem mutation (804-778) patients should undergo thyroidectomy before the age of 6 years. 'Risk level A' includes patients with mutations in codons 321, 515, 533, 600, 603, 606, 635, 649, 666, 768, 776, 790, 791, 804 (single mutation), 833, 844, 861, 891 or 912. Surgery may be postponed until the age of 10 years. However, postponing surgery and avoiding central (level VI) neck dissection in patients with risk levels A to C are only justified in families with a less aggressive MTC history and in combination with the results of basal (and calcium- or pentagastrin-stimulated) serum calcitonin levels. The moment of transition from C cell hyperplasia to MTC seems to occur when calcitonin levels rise. In patients with normal basal and stimulated calcitonin levels, the chance of micro-MTC increases significantly. Conclusions: Hereditary C cell disease acts as a model to apply the results of bedside genetic testing, age and calcitonin levels (genotype-age-calcitonin-concept) for the individual timing of thyroid surgery and its extent. [ABSTRACT FROM AUTHOR]

Hirschsprung's disease (HSCR) is a fairly frequent cause of intestinal obstruction in children. It is characterized as a sex-linked heterogonous disorder with variable severity and incomplete penetrance giving rise to a variable pattern of inheritance. Although Hirschsprung's disease occurs as an isolated phenotype in at least 70 % of cases, it is not infrequently associated with a number of congenital abnormalities and associated syndromes, demonstrating a spectrum of congenital anomalies. Certain of these syndromic phenotypes have been linked to distinct genetic sites, indicating underlying genetic associations of the disease and probable gene-gene interaction, in its pathogenesis. These associations with HSCR include Down's syndrome and other chromosomal anomalies, Waardenburg syndrome and other Dominant sensorineural deafness, the Congenital Central Hypoventilation and Mowat-Wilson and other brain-related syndromes, as well as the MEN2 and other tumour associations. A number of other autosomal recessive syndromes include the Shah-Waardenburg, the Bardet-Biedl and Cartilage-hair hypoplasia, Goldberg-Shprintzen syndromes and other syndromes related to cholesterol and fat metabolism among others. The genetics of Hirschsprung's disease are highly complex with the majority of known genetic sites relating to the main susceptibility pathways (RET an EDNRB). Non-syndromic non-familial, short-segment HSCR appears to represent a non-Mendelian condition with variable expression and sex-dependent penetrance. Syndromic and familial forms, on the other hand, have complex patterns of inheritance and being reported as autosomal dominant, recessive and polygenic patterns of inheritance. The phenotypic variability and incomplete penetrance observed in Hirschsprung's disease could also be explained by the involvement of modifier genes, especially in its syndromic forms. In this review, we look at the chromosomal and Mendelian associations and their underlying signalling pathways, to obtain a better understanding of the pathogenetic mechanisms involved in developing aganglionosis of the distal bowel. [ABSTRACT FROM AUTHOR]

Hirschsprung disease (HSCR, aganglionic megacolon) is a complex and heterogeneous disease with an incidence of 1 in 5000 live births. Despite the multifactorial determination of HSCR in the vast majority of cases, there is a monogenic subgroup for which private rare RET coding sequence mutations with high penetrance are found (45% of HSCR familial cases). An asymmetrical parental origin is observed for RET coding sequence mutations with a higher maternal inheritance. A parent-of-origin effect is usually assumed. Here we show that a differential reproductive rate for males and females also leads to an asymmetrical parental origin, which was never considered as a possible explanation till now. In the case of HSCR, we show a positive association between penetrance of the mutation and parental transmission asymmetry: no parental transmission asymmetry is observed in sporadic RET CDS mutation carrier cases for which penetrance of the mutation is low, whereas a parental transmission asymmetry is observed in affected sib-pairs for which penetrance of the mutation is higher. This allows us to conclude that the explanation for this parental asymmetry is that more severe mutations have resulted in a differential reproductive rate between male and female carriers. [ABSTRACT FROM AUTHOR]

Hirschsprung disease (HSCR, congenital colon aganglionosis) is a relatively common complex genetic condition caused by abnormal development of the enteric nervous system (ENS). Through a recent genome-wide association study conducted on Chinese HSCR patients, we identified a new HSCR contributing locus, neuregulin 1 ( NRG1; 8p12), a gene known to be involved in the development of the ENS. As genes in which disease-associated common variants are found are to be considered as candidates for the search of deleterious rare variants (RVs) in the coding sequences, we sequenced the NRG1 exons of 358 sporadic HSCR patients and 333 controls. We identified a total of 13 different heterozygous RVs including 8 non-synonymous (A28G, E134K, V266L, H347Y, P356L, V486M, A511T, P608A) and 3 synonymous amino acid substitutions (P24P, T169T, L483L), a frameshift (E239 fsX10), and a c.503-4insT insertion. Functional analysis of the most conserved non-synonymous substitutions, H347Y and P356L, showed uneven intracellular distribution and aberrant expression of the mutant proteins. Except for T169T and V486M, all variants were exclusive to HSCR patients. Overall, there was a statistically significant over-representation of NRG1 RVs in HSCR patients ( p = 0.008). We show here that not only common, but also rare variants of the NRG1 gene contribute to HSCR. This strengthens the role of NRG1. [ABSTRACT FROM AUTHOR]

Germline mutations of RET gene are pathognomonic of multiple endocrine neoplasia (MEN; MEN 2A/MEN 2B) and familial medullary thyroid carcinoma (FMTC), constituting 25% of medullary thyroid carcinomas (MTCs). We investigated RET gene mutations and polymorphisms at exons 10, 11, 13, 14, 15 and 16 in 140 samples, comprising 51 clinically diagnosed MTC patients, 39 family members of patients and 50 normal individuals. The method of choice was PCR and direct nucleotide sequencing of the PCR products. RET gene mutations were detected in 15 (29.4%) patients, with MEN 2A/FMTC in 13 patients and MEN 2B in 2 patients. Further, 39 family members of seven index cases were analysed, wherein four of the seven index cases showed identical mutations, in 13 of 25 family members. We also examined single nucleotide polymorphisms (SNPs) in RET gene exons in 101 unrelated samples. Significant differences in the allelic frequencies of SNPs at codons 691, 769, 836 and 904 between patient and control groups were not observed. However, SNP frequencies were significantly different in the Indian group as compared with other European groups. We identified two novel, rare and unique SNPs separately in single patients. Our study demonstrated presence of MEN 2A/MEN 2B/FMTC-associated mutations in accordance with the reported literature. Thus, RET gene mutations in exons 10, 11, 13, 14, 15 and 16 constitute a rapid test to confirm diagnosis and assess risk of the disease in familial MEN 2A/MEN 2B/FMTC. [ABSTRACT FROM AUTHOR]

The article presents abstracts on topics related to hypertension which include the effect of olmesartan on oxidative stress in hypertensive patients and nocturnal blood pressure in untreated essential hypertensive patients.

Hirschsprung's disease (HSCR) is a developmental disorder characterized by the absence of ganglion cells in the lower digestive tract. Aganglionosis is attributed to a disorder of the enteric nervous system (ENS) whereby ganglion cells fail to innervate the lower gastrointestinal tract during embryonic development. HSCR is a complex disease that results from the interaction of several genes and manifests with low, sex-dependent penetrance and variability in the length of the aganglionic segment. The genetic complexity observed in HSCR can be conceptually understood in light of the molecular and cellular events that take place during the ENS development. DNA alterations in any of the genes involved in the ENS development may interfere with the colonization process, and represent a primary etiology for HSCR. This review will focus on the genes known to be involved in HSCR pathology, how they interact, and on how technology advances are being employed to uncover the pathological processes underlying this disease. [ABSTRACT FROM AUTHOR]

Pheochromocytomas are rare tumors in children arising from chromaffin cells of adrenal medullary or extra-adrenal paraganglionic tissue. The tumors are characterized by synthesis, metabolism, and secretion of catecholamines. The formerly used guidelines for pheochromocytoma have been changed by recent discoveries, implementation of new approaches, and understanding of biochemistry, genetics, imaging, pathophysiology, and nomenclature of these tumors. In children, pheochromocytomas are more frequently familial, extra-adrenal, bilateral, and multifocal than in adults. Because of a highly variable clinical presentation, pheochromocytoma is often referred to as the great mimic. Measurements of plasma or urinary fractionated metanephrines are recommended as first-line biochemical tests for diagnosis, with optimum diagnostic sensitivity to be preferred over specificity. In general, localization studies must be used secondary to clinical and biochemical evidence. Adequate preoperative treatment with α-blockade is mandatory, including for pheochromocytomas that do not secrete but only synthesize catecholamines. Because approximately 40% of pheochromocytomas in children have a hereditary basis, proper genetic testing should be performed, with appropriate implications for future follow-up and treatment options. The risk for development of malignant disease depends highly on the underlying mutation, which may also impact recommendations concerning screening and surgical or systemic treatment. This article reviews recent advances in biochemistry, genetics, and imaging and outlines recommendations for improved evaluation and treatment of children with benign or malignant pheochromocytomas. [ABSTRACT FROM AUTHOR]

Zusammenfassung  Die molekulargenetische Veränderungen einiger endokriner Tumoren sind zu Teilen aufgeklärt und spiegeln die ätiologische Grundlage der Entwicklung dieser sporadischen und familiären Erkrankungen wider. Für familiäre endokrine Tumoren, die oft im Rahmen von Syndromerkrankungen entstehen, hat dies schon jetzt klinisch praktische Auswirkungen. Sie liegen im teilweise veränderten chirurgischen Vorgehen, in der Suche nach weiteren, meist endokrin aktiven Tumoren und in der Untersuchung von Familienmitgliedern zur Entdeckung weiterer Genträger (Träger der spezifischen Mutation) und gegebenenfalls einer prophylaktischen Tumortherapie. Für sporadische endokrine Tumoren verfügen wir dagegen über weit weniger klinisch verwendbare Erkenntnisse. Ausgehend von der Anamnese und dem klinischen Befund eines endokrin aktiven Tumors werden die derzeitigen Möglichkeiten einer molekulargenetischen Abklärung (Keimbahn- und Tumor-DNA) auf krankheitsspezifische Mutationen hin diskutiert und deren Bedeutung für das endokrin-chirurgische Vorgehen dargestellt. [ABSTRACT FROM AUTHOR]

The enteric nervous system (ENS) has been explored by developmental neurobiologists and medical researchers for decades. Whereas developmental biologists have been unravelling the molecular mechanisms underlying the migration, proliferation and differentiation of the neural crest derivatives that give rise to the ENS, human geneticists have been uncovering the genetic basis for diseases of the ENS, notably Hirschsprung's disease. Here we discuss the exciting recent advances, including novel transgenic and genetic tools, a broadening range of model organisms, and the pursuit of ENS stem cells as a therapeutic tool, that are bringing these fields closer together. [ABSTRACT FROM AUTHOR]

Systematic efforts are underway to decipher the genetic changes associated with tumor initiation and progression. However, widespread clinical application of this information is hampered by an inability to identify critical genetic events across the spectrum of human tumors with adequate sensitivity and scalability. Here, we have adapted high-throughput genotyping to query 238 known oncogene mutations across 1,000 human tumor samples. This approach established robust mutation distributions spanning 17 cancer types. Of 17 oncogenes analyzed, we found 14 to be mutated at least once, and 298 (30%) samples carried at least one mutation. Moreover, we identified previously unrecognized oncogene mutations in several tumor types and observed an unexpectedly high number of co-occurring mutations. These results offer a new dimension in tumor genetics, where mutations involving multiple cancer genes may be interrogated simultaneously and in 'real time' to guide cancer classification and rational therapeutic intervention. [ABSTRACT FROM AUTHOR]

Copyright of Der Pathologe is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Six multiple endocrine neoplasia (MEN) syndromes have received a level of attention that might seem disproportionate to their low prevalence. The attention has been given because their hormonal excesses cause striking metabolic expressions and because they might clarify pathways disrupted in more common tumours. The recent discovery of the main gene in each MEN syndrome has furthered our understanding of not only hereditary but also sporadic tumours and has fostered new avenues of research. [ABSTRACT FROM AUTHOR]

Two mutations on the same allele ofRETgene were revealed in a family with predisposition to multiple endocrine neoplasia (MEN) type 2A. The first mutation changes codon 634 from cysteine to serine. The second, a novel mutation in codon 641, changes alanine to serine in the transmembrane domain of the RET protein. Two mutations were present in close proximity in both the patients’ germline and tumor DNA and were absent in DNA isolated from healthy family members and control blood donors. All MEN 2A affected family members suffered from medullary thyroid carcinoma and two of ten patients for pheochromocytoma. No parathyroid gland alterations were observed in patients with twoRETgene mutations. Analysis of four genetic polymorphisms in theRETgene showed higher incidence of polymorphisms of exons 11 and 15. The observed allelic imbalance in favor of mutated allele in pheochromocytoma corresponded to higher expression of theRETgene. These observations confirm the multifactorial process leading to development of MEN 2A syndrome. [ABSTRACT FROM AUTHOR]

Hirschsprung disease (HSCR), a congenital disorder characterized by intestinal obstruction due to absence of enteric ganglia along variable lengths of the intestinal tract, occurs both in familial and sporadic cases. RET mutations have been found in approximately 50% of the families, but explains only a minority of sporadic cases. This study aims at investigating a possible role of RET in sporadic HSCR patients. Haplotypes of 13 DNA markers, within and flanking RET, have been determined for 117 sporadic HSCR patients and their parents. Strong association was observed for six markers in the 5' region of RET. The largest distortions in allele transmission were found at the same markers. One single haplotype composed of these six markers was present in 55.6% of patients versus 16.2% of controls. Odds ratios (ORs) revealed a highly increased risk of homozygotes for this haplotype to develop HSCR (OR>20). These results allowed us to conclude that RET plays a crucial role in HSCR even when no RET mutations are found. An unknown functional disease variant(s) with a dosage-dependent effect in HSCR is likely located between the promoter region and exon 2 of RET.European Journal of Human Genetics (2004) 12, 604-612. doi:10.1038/sj.ejhg.5201199 Published online 12 May 2004 [ABSTRACT FROM AUTHOR]

The study of inherited cancer syndromes has led to the identification of over 25 genes directly involved in tumorigenesis. These genes have functions as diverse as signal transduction, cell cycle control, cell-to-cell adhesion, control of apoptosis, DNA repair and the maintenance of genome stability. Most cancer syndromes have a dominant pattern of inheritance, due to germline loss-of-function mutation of a tumour suppressor gene. All the recessively inherited genes have been implicated in the maintenance of genome stability. This review summarises our current understanding of the functions of the major cancer susceptibility genes. [ABSTRACT FROM AUTHOR]