VHL-P138R and VHL-L163R Novel Variants: Mechanisms of VHL Pathogenicity Involving HIF-Dependent and HIF-Independent Actions.

The von Hippel-Lindau (VHL) disease is an autosomal dominant cancer syndrome caused by mutations in the VHL tumor suppressor gene. VHL protein (pVHL) forms a complex (VBC) with Elongins B-C, Cullin2, and Rbx1. Although other functions have been discovered, the most described function of pVHL is to recognize and target hypoxia-inducible factor (HIF) for degradation. This work comprises the functional characterization of two novel variants of the VHL gene (P138R and L163R) that have been described in our center in patients with VHL disease by in vitro, in vivo, and in silico approaches. In vitro, we found that these variants have a significantly shorter half-life compared to wild-type VHL but still form a functional VBC complex. Altered fibronectin deposition was evidenced for both variants using immunofluorescence. In vivo studies revealed that both variants failed to suppress tumor growth. By means of molecular dynamics simulations, we inspected in silico the nature of the changes introduced by each variant in the VBC complex. We have demonstrated the pathogenicity of P138R and L163R novel variants, involving HIF-dependent and HIF-independent mechanisms. These results provide the basis for future studies regarding the impact of structural alterations on posttranslational modifications that drive pVHL's fate and functions.

Genotype-Phenotype Features of Germline Variants of the TMEM127 Pheochromocytoma Susceptibility Gene: A 10-Year Update.

PURPOSE: This work aimed to evaluate genotype-phenotype associations in individuals carrying germline variants of transmembrane protein 127 gene (TMEM127), a poorly known gene that confers susceptibility to pheochromocytoma (PHEO) and paraganglioma (PGL). DESIGN: Data were collected from a registry of probands with TMEM127 variants, published reports, and public databases. MAIN OUTCOME ANALYSIS: Clinical, genetic, and functional associations were determined. RESULTS: The cohort comprised 110 index patients (111 variants) with a mean age of 45 years (range, 21-84 years). Females were predominant (76 vs 34, P < .001). Most patients had PHEO (n = 94; 85.5%), although PGL (n = 10; 9%) and renal cell carcinoma (RCC, n = 6; 5.4%) were also detected, either alone or in combination with PHEO. One-third of the cases had multiple tumors, and known family history was reported in 15.4%. Metastatic PHEO/PGL was rare (2.8%). Epinephrine alone, or combined with norepinephrine, accounted for 82% of the catecholamine profiles of PHEO/PGLs. Most variants (n = 63) occurred only once and 13 were recurrent (2-12 times). Although nontruncating variants were less frequent than truncating changes overall, they were predominant in non-PHEO clinical presentations (36% PHEO-only vs 69% other, P < .001) and clustered disproportionately within transmembrane regions (P < .01), underscoring the relevance of these domains for TMEM127 function. Integration of clinical and previous experimental data supported classification of variants into 4 groups based on mutation type, localization, and predicted disruption. CONCLUSIONS: Patients with TMEM127 variants often resemble sporadic nonmetastatic PHEOs. PGL and RCC may also co-occur, although their causal link requires further evaluation. We propose a new classification to predict variant pathogenicity and assist with carrier surveillance.

Cytochrome 450 metabolites of arachidonic acid (20-HETE, 11,12-EET and 14,15-EET) promote pheochromocytoma cell growth and tumor associated angiogenesis.

The importance of cytochrome P450 (CYP)-derived arachidonic acid (AA) metabolites, 20-hydroxyeicosatetraenoic acid (20-HETE) and epoxyeicosatrienoic acids (EETs) as tumor growth promotors has already been described in several cancer types. The aim of this study was to evaluate the role of these compounds in the biology of pheochromocytoma/paraganglioma. These tumors originate from chromaffin cells derived from adrenal medulla (pheochromocytomas) or extra-adrenal autonomic paraganglia (paragangliomas), and they represent the most common hereditary endocrine neoplasia. According to mutations in the driver genes, these tumors are divided in two clusters: pseudo-hypoxic and kinase-signaling EETs, but not 20-HETE, exhibited a potent ability to sustain growth in a murine pheochromocytoma cell line (MPC) in vitro, EETs promoted an increase in cell proliferation and a decrease in cell apoptosis. In a mouse model of pheochromocytoma, the inhibition of CYP-mediated AA metabolism using 1-aminobenzotriazol resulted in slower tumor growth, a decreased vascularization, and a lower final volume. Also, the expression of AA-metabolizing CYP monooxygenases was detected in tumor samples from human origin, being their apparent abundance and the production of both metabolites higher in tumors from the kinase-signaling cluster. This is the first evidence of the importance of CYP- derived AA metabolites in the biology and development of pheochromocytoma/paraganglioma tumors.

Feocromocitoma: nuevas perspectivas en diagnóstico y seguimiento / Pheochromocytoma: new insights in diagnosis and monitoring

La hipertensión arterial es una patología de menor frecuencia en pediatría que en la edad adulta, sin embargo existen diversas etiologías que la pueden originar y es fundamental realizar diagnóstico certero de las mismas. El feocromocitoma es un tumor endócrino, originado en el tejido cromafin y constituye una importante causa de hipertensión secundaria. Puede ser esporádico o formar parte de diversos síndromes familiares, como la enfermedad de von Hippel Lindau, la Neoplasia Endócrina Múltiple tipo 2, los síndromes de Feocromocitoma/ Paraganglioma Familiar tipo 1, 2, 3 y 4, y la Neurofibromatosis tipo 1. Además, en la actualidad se han descrito más de 15 genes susceptibles que han sido implicados en casos familiares. Siendo tumores altamente heredables, se recomienda realizar pruebas genéticas en todos los pacientes, incluso en aquellos con una historia familiar comprobable. El diagnóstico de la enfermedad hereditaria mejora la atención del paciente y permite el diagnóstico precoz en familiares

Arterial hypertension is a less frequent condition in paediatrics than in adulthood, but due to the high proportion of secondary causes, the search for the aetiology is crucial for an adequate diagnosis and treatment. Pheochromocytoma is an endocrine tumor originated in the chromaffin tissue. It is an important cause of secondary hypertension. It can be sporadic or part of several hereditary syndromes, such as von Hippel Lindau disease, Multiple Endocrine Neoplasia type 2, Pheochromocytoma/Familiar Paraganglioma syndromes type 1, 2, 3 and 4, and type 1 Neurofibromatosis. In addition, more than 15 susceptible genes have been described in familial pheochromocytoma. Being highly heritable tumors, genetic testing of tumor susceptibility is recommended in all patients, even in absence of a family history. The diagnosis of the hereditary disease improves the patient's attention and allows early diagnosis in relatives

VHL Germline Mutations in Argentinian Patients with Clinical Diagnoses or Single Typical Manifestations of Type 1 von Hippel-Lindau Disease.

AIMS: von Hippel-Lindau (VHL) disease is caused by mutations in the VHL tumor suppressor gene. As tumors that develop in the context of VHL also occur in a sporadic context, the frequency of this syndrome may be underestimated. Our aim was to identify VHL gene mutations in Argentinian patients who fulfilled the clinical criteria for type 1 VHL disease and in patients with VHL-associated manifestations that did not meet these criteria. METHODS: We performed a retrospective cohort study, including patients who met current diagnostic criteria for type 1 VHL (Group 1, n = 19) and patients with VHL-associated manifestations that did not meet these criteria (Group 2, n = 21). Genomic DNA was extracted from peripheral blood leukocytes. Mutation analysis involved DNA sequencing, while large deletions were determined by universal primer quantitative fluorescent multiplex polymerase chain reaction (UPQFM-PCR) and multiplex ligation-dependent probe amplification (MLPA) analysis. RESULTS: VHL mutations were detected in 16/19 (84.2%) patients in Group 1 and included: gross deletions (4/16); nonsense mutations (6/16); frameshift mutations (4/16); missense mutations (1/16); and splicing mutations (1/16). Three of these mutations were novel. No alterations were found in 3 of 19 VHL patients. In Group 2, one nonsense VHL mutation was detected in a young patient with a solitary central nervous system hemangioblastoma without familial history. A study of 30 first-degree relatives revealed four carriers with VHL mutations. CONCLUSIONS: We found three novel mutations in the VHL gene in our population. Our results emphasize the importance of a complete genetic study of VHL to confirm type 1 VHL disease, not only in patients with clinical diagnostic criteria but also in those presenting a single typical manifestation.

Recurrent Mutations of Chromatin-Remodeling Genes and Kinase Receptors in Pheochromocytomas and Paragangliomas.

PURPOSE: Pheochromocytomas and paragangliomas (PPGL) are genetically heterogeneous tumors of neural crest origin, but the molecular basis of most PPGLs is unknown. EXPERIMENTAL DESIGN: We performed exome or transcriptome sequencing of 43 samples from 41 patients. A validation set of 136 PPGLs was used for amplicon-specific resequencing. In addition, a subset of these tumors was subjected to microarray-based transcription, protein expression, and histone methylation analysis by Western blotting or immunohistochemistry. In vitro analysis of mutants was performed in cell lines. RESULTS: We detected mutations in chromatin-remodeling genes, including histone-methyltransferases, histone-demethylases, and histones in 11 samples from 8 patients (20%). In particular, we characterized a new cancer syndrome involving PPGLs and giant cell tumors of bone (GCT) caused by a postzygotic G34W mutation of the histone 3.3 gene, H3F3A Furthermore, mutations in kinase genes were detected in samples from 15 patients (37%). Among those, a novel germline kinase domain mutation of MERTK detected in a patient with PPGL and medullary thyroid carcinoma was found to activate signaling downstream of this receptor. Recurrent germline and somatic mutations were also detected in MET, including a familial case and sporadic PPGLs. Importantly, in each of these three genes, mutations were also detected in the validation group. In addition, a somatic oncogenic hotspot FGFR1 mutation was found in a sporadic tumor. CONCLUSIONS: This study implicates chromatin-remodeling and kinase variants as frequent genetic events in PPGLs, many of which have no other known germline driver mutation. MERTK, MET, and H3F3A emerge as novel PPGL susceptibility genes. Clin Cancer Res; 22(9); 2301-10. ©2015 AACR.

Characterization of endolymphatic sac tumors and von Hippel-Lindau disease in the International Endolymphatic Sac Tumor Registry.

BACKGROUND: Endolymphatic sac tumors (ELSTs) are, with a prevalence of up to 16%, a component of von Hippel-Lindau (VHL) disease. Data from international registries regarding heritable fraction and characteristics, germline VHL mutation frequency, and prevalence are lacking. METHODS: Systematic registration of ELSTs from international centers of otorhinolaryngology and from multidisciplinary VHL centers' registries was performed. Molecular genetic analyses of the VHL gene were offered to all patients. RESULTS: Our population-based registry comprised 93 patients with ELST and 1789 patients with VHL. The prevalence of VHL germline mutations in apparently sporadic ELSTs was 39%. The prevalence of ELSTs in patients with VHL was 3.6%. ELST was the initial manifestation in 32% of patients with VHL-ELST. CONCLUSION: Prevalence of ELST in VHL disease is much lower compared to the literature. VHL-associated ELSTs can be the first presentation of the syndrome and mimic sporadic tumors, thus emphasizing the need of molecular testing in all presentations of ELST. © 2015 Wiley Periodicals, Inc. Head Neck 38: 673-679, 2016.

Pheochromocytoma associated with pregnancy: unexpected favourable outcome in patients diagnosed after delivery.

OBJECTIVE: The objective of this study is to present the clinical findings and outcome of a large cohort of pregnant women with pheochromocytoma (PHEO) with the aim to contribute to the better recognition, detection and management of pregnancy-related PHEO in the population of pregnant patients with hypertension. METHODS: This is a longitudinal follow-up of a single cohort of 15 patients aged 19-40 years with PHEO associated with pregnancy. Urinary catecholamines and vanillylmandelic acid (VMA) were analysed. Ret proto-oncogene, SDHB and VHL mutations were determined in germline DNA from seven women using PCR followed by direct sequencing. RESULTS: During pregnancy, all women presented typical features of catecholamines excess. Nevertheless, biochemical diagnosis was performed only in four out of 15 cases during pregnancy and postpartum in the remaining 11. Paroxysmal hypertension was the predominant pattern. Urinary catecholamines and/or VMA were increased in all patients. Tumours were adrenal in 13 patients and extraadrenal in two. Mutations in the Ret proto-oncogene were found in four patients, in the VHL gene in one and in the SDHB gene in one. Antihypertensive treatment resulted in effective control of blood pressure and all women survived. In the group of women diagnosed postpartum, one foetus demised. Newborns from mothers receiving adequate treatment survived. One woman left the hospital after caesarean section but before PHEO surgery became pregnant again and this gestation ended with maternal-foetal dead. CONCLUSION: A high index of suspicion in all pregnant women presenting hypertension mainly paroxystic during any gestational phase and/or a history of familial PHEO are the keys to disclose this important diagnosis.

Outcomes of adrenal-sparing surgery or total adrenalectomy in phaeochromocytoma associated with multiple endocrine neoplasia type 2: an international retrospective population-based study.

BACKGROUND: The prevention of medullary thyroid cancer in patients with multiple endocrine neoplasia type 2 syndrome has demonstrated the ability of molecular diagnosis and prophylactic surgery to improve patient outcomes. However, the other major neoplasia associated with multiple endocrine neoplasia type 2, phaeochromocytoma, is not as well characterised in terms of occurrence and treatment outcomes. In this study, we aimed to systematically characterise the outcomes of management of phaeochromocytoma associated with multiple endocrine neoplasia type 2. METHODS: This multinational observational retrospective population-based study compiled data on patients with multiple endocrine neoplasia type 2 from 30 academic medical centres across Europe, the Americas, and Asia. Patients were included if they were carriers of germline pathogenic mutations of the RET gene, or were first-degree relatives with histologically proven medullary thyroid cancer and phaeochromocytoma. We gathered clinical information about patients'RET genotype, type of treatment for phaeochromocytoma (ie, unilateral or bilateral operations as adrenalectomy or adrenal-sparing surgery, and as open or endoscopic operations), and postoperative outcomes (adrenal function, malignancy, and death). The type of surgery was decided by each investigator and the timing of surgery was patient driven. The primary aim of our analysis was to compare disease-free survival after either adrenal-sparing surgery or adrenalectomy. FINDINGS: 1210 patients with multiple endocrine neoplasia type 2 were included in our database, 563 of whom had phaeochromocytoma. Treatment was adrenalectomy in 438 (79%) of 552 operated patients, and adrenal-sparing surgery in 114 (21%). Phaeochromocytoma recurrence occurred in four (3%) of 153 of the operated glands after adrenal-sparing surgery after 6-13 years, compared with 11 (2%) of 717 glands operated by adrenalectomy (p=0.57). Postoperative adrenal insufficiency or steroid dependency developed in 292 (86%) of 339 patients with bilateral phaeochromocytoma who underwent surgery. However, 47 (57%) of 82 patients with bilateral phaeochromocytoma who underwent adrenal-sparing surgery did not become steroid dependent. INTERPRETATION: The treatment of multiple endocrine neoplasia type 2-related phaeochromocytoma continues to rely on adrenalectomies with their associated Addisonian-like complications and consequent lifelong dependency on steroids. Adrenal-sparing surgery, a highly successful treatment option in experienced centres, should be the surgical approach of choice to reduce these complications.

Long-term prognosis of patients with pediatric pheochromocytoma.

A third of patients with paraganglial tumors, pheochromocytoma, and paraganglioma, carry germline mutations in one of the susceptibility genes, RET, VHL, NF1, SDHAF2, SDHA, SDHB, SDHC, SDHD, TMEM127, and MAX. Despite increasing importance, data for long-term prognosis are scarce in pediatric presentations. The European-American-Pheochromocytoma-Paraganglioma-Registry, with a total of 2001 patients with confirmed paraganglial tumors, was the platform for this study. Molecular genetic and phenotypic classification and assessment of gene-specific long-term outcome with second and/or malignant paraganglial tumors and life expectancy were performed in patients diagnosed at <18 years. Of 177 eligible registrants, 80% had mutations, 49% VHL, 15% SDHB, 10% SDHD, 4% NF1, and one patient each in RET, SDHA, and SDHC. A second primary paraganglial tumor developed in 38% with increasing frequency over time, reaching 50% at 30 years after initial diagnosis. Their prevalence was associated with hereditary disease (P=0.001), particularly in VHL and SDHD mutation carriers (VHL vs others, P=0.001 and SDHD vs others, P=0.042). A total of 16 (9%) patients with hereditary disease had malignant tumors, ten at initial diagnosis and another six during follow-up. The highest prevalence was associated with SDHB (SDHB vs others, P<0.001). Eight patients died (5%), all of whom had germline mutations. Mean life expectancy was 62 years with hereditary disease. Hereditary disease and the underlying germline mutation define the long-term prognosis of pediatric patients in terms of prevalence and time of second primaries, malignant transformation, and survival. Based on these data, gene-adjusted, specific surveillance guidelines can help effective preventive medicine.

Overexpression of the insulin-like growth factor 1 receptor (IGF-1R) is associated with malignancy in familial pheochromocytomas and paragangliomas.

CONTEXT: Pheochromocytomas and paragangliomas (pheo/pgl) are neuroendocrine tumours derived from chromaffin cells. Although mostly benign, up to 26% of pheo/pgl will undergo malignant transformation. Reliable histological signs to differentiate benign pheo/pgl from malignant tumours are currently lacking. Increased IGF-1R expression has been shown during progression to metastatic phenotypes of several types of cancer. OBJECTIVE: To analyse the distribution and expression of the IGF-1R in pheo/pgl of different genetic origin and degree of malignancy. MEASUREMENTS: We studied the expression of the IGF-1R protein by immunohistochemistry, in 40 primary tumours from patients with pheo/pgl from different genetic aetiology (11 of 29 metastatic/nonmetastatic diseases). RESULTS: We found a strong association between increased expression of IGF-1R and malignant behaviour regardless of the age at diagnosis and the genetic aetiology. IGF-1R labelling was mostly weak in primary tumours from patients with nonmetastatic pheo/pgl. Conversely, intense IGF-1R labelling was predominant in cases of pheo/pgl with confirmed metastatic disease. The risk of metastases was 11·7 times higher if tumour IGF-1R labelling was intense independently of age at diagnosis. The probability of remaining free of metastases was higher in patients with pheo/pgl scored weak for IGF-1R at 60 months and more than twofold higher at 120 months of follow-up than in patients with intense IGF-1R labelling in their primary tumours. CONCLUSIONS: Our results strongly suggest that IGF-1R is associated with malignancy in familial pheo/pgl and that IGF-1R expression in the primary tumour might be a useful tool to detect those patients harbouring pheo/pgl who have an increased risk of metastasis.

Igf-I regulates pheochromocytoma cell proliferation and survival in vitro and in vivo.

IGFs are involved in malignant transformation and growth of several tissues, including the adrenal medulla. The present study was designed to evaluate the impact of IGF-I on pheochromocytoma development. We used a murine pheochromocytoma (MPC) cell line (MPC4/30) and an animal model with a reduction of 75% in circulating IGF-I levels [liver-IGF-I-deficient (LID) mice] to perform studies in vitro and in vivo. We found that, in culture, IGF-I stimulation increases proliferation, migration, and anchorage-independent growth, whereas it inhibits apoptosis of MPC cells. When injected to control and to LID mice, MPC cells grow and form tumors with features of pheochromocytoma. Six weeks after cell inoculation, all control mice developed sc tumors. In contrast, in 73% of LID mice, tumor development was delayed to 7-12 wk, and the remaining 27% did not develop tumors up to 12 wk after inoculation. LID mice harboring MPC cells and treated with recombinant human IGF-I (LID+) developed tumors as controls. Tumors developed in control, LID, and LID+ mice had similar histology and were similarly positive for IGF-I receptor expression. The apoptotic index was higher in tumors from LID mice compared with those from control mice, whereas vascular density was decreased. In summary, our work demonstrates that IGF-I has a critical role in maintaining tumor phenotype and survival of already transformed pheochromocytoma cells and is required for the initial establishment of these tumors, providing encouragement to carry on research studies to address the IGF-I/IGF-I receptor system as a target of therapeutic strategies for pheochromocytoma treatment in the future.

MAX mutations cause hereditary and sporadic pheochromocytoma and paraganglioma.

PURPOSE: Pheochromocytomas (PCC) and paragangliomas (PGL) are genetically heterogeneous neural crest-derived neoplasms. Recently we identified germline mutations in a new tumor suppressor susceptibility gene, MAX (MYC-associated factor X), which predisposes carriers to PCC. How MAX mutations contribute to PCC/PGL and associated phenotypes remain unclear. This study aimed to examine the prevalence and associated phenotypic features of germline and somatic MAX mutations in PCC/PGL. DESIGN: We sequenced MAX in 1,694 patients with PCC or PGL (without mutations in other major susceptibility genes) from 17 independent referral centers. We screened for large deletions/duplications in 1,535 patients using a multiplex PCR-based method. Somatic mutations were searched for in tumors from an additional 245 patients. The frequency and type of MAX mutation was assessed overall and by clinical characteristics. RESULTS: Sixteen MAX pathogenic mutations were identified in 23 index patients. All had adrenal tumors, including 13 bilateral or multiple PCCs within the same gland (P < 0.001), 15.8% developed additional tumors at thoracoabdominal sites, and 37% had familial antecedents. Age at diagnosis was lower (P = 0.001) in MAX mutation carriers compared with nonmutated cases. Two patients (10.5%) developed metastatic disease. A mutation affecting MAX was found in five tumors, four of them confirmed as somatic (1.65%). MAX tumors were characterized by substantial increases in normetanephrine, associated with normal or minor increases in metanephrine. CONCLUSIONS: Germline mutations in MAX are responsible for 1.12% of PCC/PGL in patients without evidence of other known mutations and should be considered in the genetic work-up of these patients.

Risk profiles and penetrance estimations in multiple endocrine neoplasia type 2A caused by germline RET mutations located in exon 10.

Multiple endocrine neoplasia type 2 is characterized by germline mutations in RET. For exon 10, comprehensive molecular and corresponding phenotypic data are scarce. The International RET Exon 10 Consortium, comprising 27 centers from 15 countries, analyzed patients with RET exon 10 mutations for clinical-risk profiles. Presentation, age-dependent penetrance, and stage at presentation of medullary thyroid carcinoma (MTC), pheochromocytoma, and hyperparathyroidism were studied. A total of 340 subjects from 103 families, age 4-86, were registered. There were 21 distinct single nucleotide germline mutations located in codons 609 (45 subjects), 611 (50), 618 (94), and 620 (151). MTC was present in 263 registrants, pheochromocytoma in 54, and hyperparathyroidism in 8 subjects. Of the patients with MTC, 53% were detected when asymptomatic, and among those with pheochromocytoma, 54%. Penetrance for MTC was 4% by age 10, 25% by 25, and 80% by 50. Codon-associated penetrance by age 50 ranged from 60% (codon 611) to 86% (620). More advanced stage and increasing risk of metastases correlated with mutation in codon position (609→620) near the juxtamembrane domain. Our data provide rigorous bases for timing of premorbid diagnosis and personalized treatment/prophylactic procedure decisions depending on specific RET exon 10 codons affected.

Spectrum and prevalence of FP/TMEM127 gene mutations in pheochromocytomas and paragangliomas.

CONTEXT: Pheochromocytomas and paragangliomas are genetically heterogeneous neural crest-derived neoplasms. We recently identified germline mutations of the novel transmembrane-encoding gene FP/TMEM127 in familial and sporadic pheochromocytomas consistent with a tumor suppressor effect. OBJECTIVES: To examine the prevalence and spectrum of FP/TMEM127 mutations in pheochromocytomas and paragangliomas and to test the effect of mutations in vitro. DESIGN, SETTING, AND PARTICIPANTS: We sequenced the FP/TMEM127 gene in 990 individuals with pheochromocytomas and/or paragangliomas, including 898 previously unreported cases without mutations in other susceptibility genes from 8 independent worldwide referral centers between January 2009 and June 2010. A multiplex polymerase chain reaction-based method was developed to screen for large gene deletions in 545 of these samples. Confocal microscopy of 5 transfected mutant proteins was used to determine their subcellular localization. MAIN OUTCOME MEASURES: The frequency and type of FP/TMEM127 mutation or deletion was assessed and correlated with clinical variables; the subcellular localization of 5 overexpressed mutants was compared with wild-type FP/TMEM127 protein. RESULTS: We identified 19 potentially pathogenic FP/TMEM127 germline mutations in 20 independent families, but no large deletions were detected. All mutation carriers had adrenal tumors, including 7 bilateral (P = 2.7 × 10(-4)) and/or with familial disease (5 of 20 samples; P = .005). The median age at disease onset in the FP/TMEM127 mutation group was similar to that of patients without a mutation (41.5 vs 45 years, respectively; P = .54). The most common presentation was that of a single benign adrenal tumor in patients older than 40 years. Malignancy was seen in 1 mutation carrier (5%). Expression of 5 novel FP/TMEM127 mutations in cell lines revealed diffuse localization of the mutant proteins in contrast with the discrete multiorganelle distribution of wild-type TMEM127. CONCLUSIONS: Germline mutations of FP/TMEM127 were associated with pheochromocytoma but not paraganglioma and occurred in an age group frequently excluded from genetic screening algorithms. Disease-associated mutations disrupt intracellular distribution of the FP/TMEM127 protein.

Estrés psicosocial y baja resiliencia, un factor de riesgo de hipertensión arterial / Psychosocial Stress and Low Resilience: a Risk Factor for Hypertension

Introducción El estrés psicosocial crónico (EPC) fue propuesto como un factor de riesgo cardiovascular (FRC); sin embargo, la complejidad y la falta de medidas objetivas para evaluarlo, unidas al hecho de que no todas las personas reaccionan ante él de igual manera, determinaron que en la actualidad no se cuente con estudios concluyentes al respecto. Objetivos Determinar si la baja resiliencia (BR) frente al EPC se asocia con hipertensión arterial y daño de órgano blanco en pacientes ambulatorios libres de tratamiento que concurren a realizarse un examen periódico de salud y comprobar si esta asociación tiene relación con el patrón de activación neurohormonal. Material y métodos Se realizó un estudio preliminar, observacional transversal, en el que se enrolaron en forma consecutiva 53 individuos, 32 varones y 21 mujeres. Los pacientes completaron dos cuestionarios: uno para medir EPC y el otro, la Escala de Resiliencia de Connor-Davidson. Quedaron divididos en cuatro grupos: 1, sin EPC y con resiliencia normal (RN); 2, sin EPC y con baja resiliencia (BR); 3, con EPC y RN; 4, con EPC y BR. Resultados El porcentaje de hipertensos fue superior en el grupo 4 (p < 0,001), como también el de individuos con incremento de la circunferencia de la cintura (ICC) (p = 0,05). Si bien los niveles de noradrenalina, cortisol y ácido vanililmandélico fueron ligeramente superiores en el grupo 4, las diferencias no alcanzaron significación estadística. Para determinar si el EPC unido a BR es un factor de riesgo para el desarrollo de hipertensión arterial se empleó un modelo de regresión logística, controlado por confundidores; el odds ratio fue de 10,9 con intervalos de confianza del 95%, inferior de 1,8 y superior de 65,2. Conclusiones Datos preliminares sugieren que individuos con EPC unido a BR tienen un riesgo alto para el desarrollo de hipertensión arterial.

Background Chronic psychosocial stress (CPSS) has been proposed as a risk factor for cardiovascular disease (CVD); yet there are not conclusive studies supporting this theory due to the complexity and the lack of objective assessment measures, together with the absence of homogeneous reactions towards CPSS. Objectives To determine the presence of an association between low resilience (LR) to chronic PSS and hypertension and target organ damage in untreated outpatients undergoing a routine health examination, and to determine whether this association is related to the pattern of neurohumoral activation. Material and Methods We conducted a preliminary observational and cross-sectional study that enrolled 53 consecutive patients, 32 men and 21 women. The patients answered two questionnaires: one measured CPSS and the other the Connor-Davidson Resilience Scale. Patients were divided into four groups: 1, no CPSS and normal resilience (NR); 2, no CPPS and low resilience (LR) 3, with CPSS and NR; 4 with CPSS and LR. Results The prevalence of hypertension and increased waist circumference (IWC) was greater in group 4 (p<0.001 and p=0.05, respectively). The plasma levels of norepinephrine, cortisol and vanillyl mandelic acid were slightly increased in group 4, yet these differences were not significant. A logistic regression model was used to control for confounding in order to determine whether CPPS together with LR constitute a risk factor for the development of hypertension; odds ratio, 10.9, 95% CI: 1.7-65.2. Conclusions These preliminary data suggest that subjects with CPPS and LR have high risk for the development of hypertension.

VHL disease.

von Hippel-Lindau disease (VHL) disease increases susceptibility to several malignancies, including renal cell carcinoma, haemangioblastomas of the central nervous system or retina and phaeochromocytomas. The VHL tumour suppressor gene, responsible for the disease, encodes for a major regulator of the hypoxic response by targeting the transcription factor hypoxia inducible factor (HIF) for degradation. In this review, we present a synopsis of clinical features of the disease and emphasise unique aspects of VHL syndrome in the paediatric population. Genotype-phenotype associations based on the risk of phaeochromocytoma have pointed to the existence of additional, HIF-independent functions of VHL that remain underexplored. We also examine the progress on these pleiotropic roles of VHL, which contribute to explain clinical features of VHL disease. These advances have important translational implications and are likely to offer a new host of therapeutic options to individuals affected by the disease in the future.

Mutations of the metabolic genes IDH1, IDH2, and SDHAF2 are not major determinants of the pseudohypoxic phenotype of sporadic pheochromocytomas and paragangliomas.

CONTEXT: Pheochromocytomas and paragangliomas are genetically heterogeneous tumors of neural crest origin. Approximately half of these tumors activate a pseudohypoxic transcription response, which is due in a minority of the cases to germline mutations of the VHL gene or the genes encoding subunits of the metabolic enzyme succinate dehydrogenase (SDH), SDHB, SDHC, or SDHD. However, the genetic basis of the hypoxic-like profile of the remaining tumors is undetermined. Mutations in genes involved in the energy metabolism, isocitrate dehydrogenase 1 (IDH1) and -2 (IDH2) and SDHAF2, a component of SDH, can mimic a pseudohypoxic state. DESIGN: We examined the sequence spanning the mutation-susceptible codons 132 of IDH1 and 172 of IDH2, and the entire coding region of SDHAF2, in 104 pheochromocytomas and paragangliomas, including tumors with a pseudohypoxic expression profile. RESULTS: We did not find mutations in IDH1, IDH2, or SDHAF2 in any of the tumors in this cohort. CONCLUSION: Conserved residues of IDH1 and IDH2 or the SDHAF2 gene are not frequently mutated in pheochromocytomas and paragangliomas. The molecular basis for activation of a hypoxic response in the majority of tumors without VHL or SDH mutations remains to be defined.

Acute effects of testosterone infusion on the serum luteinizing hormone profile in eumenorrheic and polycystic ovary syndrome adolescents.

CONTEXT: Little is known about the neuroendocrine effects of androgens on the GnRH-LH unit in females. OBJECTIVE: Our objective was to evaluate androgen negative feedback on the GnRH-LH axis in eumenorrheic and polycystic ovary syndrome (PCOS) adolescents. DESIGN AND SETTING: We conducted a prospective, longitudinal, randomized, double-blind study at a pediatric endocrinology clinical research center. PARTICIPANTS: Seven nonobese PCOS adolescents and seven matched controls (C) were studied in the early follicular phase of three consecutive menstrual cycles or in three consecutive months. INTERVENTION: Pulsatile LH release was determined during saline [baseline (B)] and constant testosterone (T) infusions: low dose (T-LD) 0.75 and high dose (T-HD) 2.5 mg/12 h iv. Blood samples were drawn every 20 min overnight. MAIN OUTCOME MEASURES: LH (immunofluorometric assay) and T (electrochemiluminescence immunoassay) were determined at B, and during both T-LD and T-HD. LH profiles were analyzed by deconvolution and approximate entropy analyses. RESULTS: On T-LD, C and PCOS serum T levels increased 2- to 3-fold vs. B. On T-HD, T values doubled in both groups vs. T-LD. Controls on T-LD had greater 12-h pulsatile LH secretion rate (P < 0.05 vs. B) and on T-HD had lower mean, pulsatile, basal LH release and LH approximate entropy (vs. B, P < 0.05). PCOS did not respond to T-LD. High-dose T did not alter mean LH in PCOS but increased pulsatile and reduced basal LH secretion. CONCLUSIONS: PCOS adolescents have impaired suppression of pulsatile LH secretion rate consistent with reduced androgen negative feedback. Attenuation of T feedback in nonobese adolescents with PCOS extends the pathophysiology of this syndrome.