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Objective: Pheochromocytomas/paragangliomas (PPGL) are rare neuroendocrine tumors arising from chromaffin cells of the adrenal medulla or from neural-crest derived sympathetic tissue. They secrete catecholamines in varying amounts, which accounts for their symptomatology. Hypertension is the most common sign, found in approximately 95% of patients. Nowadays, biochemical testing remains the simplest and most widely available method to assess PPGL in first intention. Identification of mutations in known susceptibility genes may help further refining tumor characterization and prognosis assessment. The objective of this study was to analyze clinical characteristics of PPGL from Belgium according to their secretory and genetic profiles. Design and method: We retrospectively analyzed a cohort of 120 cases of non-syndromic PPGL diagnosed in 19 Belgian centres. Clinical characteristics were correlated with three catecholamine phenotypes based on urinary metanephrines (noradrenergic, adrenergic and silent) and with the results of genetic screening. Results: Our cohort included a majority of women (59%). The mean age at diagnosis was 47 ± 7 years. We documented the prevalence of pediatric (7.5%), extra-adrenal (13.3%), bilateral (2.9%), multifocal (5.1%), recurrent (8.5%), metastatic (7.6%) and familial (5.9%) cases. While the yield of positive genetic screening was low (15%), the presence of at least one of these criteria was associated with a 4-fold increased prevalence of mutation (30.3 vs 8.5%; p = 0.03). In the subset in whom metanephrines values were available (n = 62), the prevalence of adrenergic, noradrenergic and silent phenotypes was 58%, 34% and 8% respectively. Patients belonging to these three subsets differed by age at diagnosis (51 ± 14; 38 ± 17; 42 ± 13 years; p = 0.009), the proportion of extra-adrenal tumors (2.8%; 9.5%; 40%; p = 0.016), pediatric (2.8%; 19%; 0%; p = 0.074) and familial (0%; 18.8%; 0%; p = 0.041) cases. Finally, an excess of dopamine secre

CNOT1 is a member of the CCR4-NOT complex, which is a master regulator, orchestrating gene expression, RNA deadenylation, and protein ubiquitination. We report on 39 individuals with heterozygous de novo CNOT1 variants, including missense, splice site, and nonsense variants, who present with a clinical spectrum of intellectual disability, motor delay, speech delay, seizures, hypotonia, and behavioral problems. To link CNOT1 dysfunction to the neurodevelopmental phenotype observed, we generated variant-specific Drosophila models, which showed learning and memory defects upon CNOT1 knockdown. Introduction of human wild-type CNOT1 was able to rescue this phenotype, whereas mutants could not or only partially, supporting our hypothesis that CNOT1 impairment results in neurodevelopmental delay. Furthermore, the genetic interaction with autism-spectrum genes, such as ASH1L, DYRK1A, MED13, and SHANK3, was impaired in our Drosophila models. Molecular characterization of CNOT1 variants revealed normal CNOT1 expression levels, with both mutant and wild-type alleles expressed at similar levels. Analysis of protein-protein interactions with other members indicated that the CCR4-NOT complex remained intact. An integrated omics approach of patient-derived genomics and transcriptomics data suggested only minimal effects on endonucleolytic nonsense-mediated mRNA decay components, suggesting that de novo CNOT1 variants are likely haploinsufficient hypomorph or neomorph, rather than dominant negative. In summary, we provide strong evidence that de novo CNOT1 variants cause neurodevelopmental delay with a wide range of additional co-morbidities. Whereas the underlying pathophysiological mechanism warrants further analysis, our data demonstrate an essential and central role of the CCR4-NOT complex in human brain development.

Context: Pheochromocytomas and paragangliomas (PPGLs) are rare neuroendocrine, usually benign, tumors. Currently, the only reliable criterion of malignancy is the presence of metastases. Objective: The aim of this study was to identify genes associated with malignancy in PPGLs. Design: Transcriptomic profiling was performed on 40 benign and 11 malignant PPGLs. Genes showing a significantly different expression between benign and malignant PPGLs with a ratio ≥4 were confirmed and tested in an independent series by quantitative real-time polymerase chain reaction (qRT-PCR). Immunohistochemistry was performed for the validated genes on 109 benign and 32 malignant PPGLs. Functional assays were performed with hPheo1 cells. Setting: This study was conducted at the Department of Pathology of the Erasmus MC University Medical Center Rotterdam Human Molecular Genetics laboratory of the de Duve Institute, University of Louvain. Patients: PPGL samples from 179 patients, diagnosed between 1972 and 2015, were included. Main outcome measures: Associations between gene expression and malignancy were tested using supervised clustering approaches. Results: Ten differentially expressed genes were selected based on messenger RNA (mRNA) expression array data. Contactin 4 (CNTN4) was overexpressed in malignant vs benign tumors [4.62-fold; false discovery rate (FDR), 0.001]. Overexpression at the mRNA level was confirmed using qRT-PCR (2.90-fold, P = 0.02; validation set: 4.26-fold, P = 0.005). Consistent findings were obtained in The Cancer Genome Atlas cohort (2.7-fold; FDR, 0.02). CNTN4 protein was more frequently expressed in malignant than in benign PPGLs by immunohistochemistry (58% vs 17%; P = 0.002). Survival after 7 days of culture under starvation conditions was significantly enhanced in hPheo1 cells transfected with CNTN4 complementary DNA. Conclusion: CNTN4 expression is consistently associated with malignant behavior in PPGLs.

The serine/threonine kinase With-No-Lysine (K) Kinase 1 (WNK1) activates the thiazide-sensitive Na+/Cl− cotransporter through phosphorylation of STE20/SPS1-related proline/alanine-rich kinase, another serine/threonine kinase encoded by STK39. The aim of this study was to look for association between WNK1 and STK39 gene variants, and blood pressure (BP) and hypertension. Seven hundred seventy-nine Caucasian hypertensive patients (HYP) recruited in 6 academic centers from Belgium, and 906 normotensive (NT) controls were genotyped for 5 single nucleotide polymorphisms—rs3754777, rs6749447, rs35929607 (STK39), rs1468326, and rs765250 (WNK1)—using the Snapshot method. The rare TT genotype at the rs3754777 locus (STK39) was overrepresented in HYP versus NT (7.3% vs 3.0%, P = 0.0002). In the whole study population, the multivariable-adjusted odds ratio (OR) for having hypertension associated with the TT genotype was 5.9 (95% confidence interval: 2.2–15.6), and systolic BP was 10 mm Hg higher in TT compared with wild-type subjects (140.1 vs 130.4 mm Hg, P = 0.002). Similarly, the AA genotype at the rs1468326 locus (WNK1) was twice as frequent in HYP versus NT (5.5% vs 2.3%, P < 0.0001), and associated with an increased adjusted OR of hypertension (4.1; 1.5–11.7) and a higher systolic BP (139.8 vs 130.1 mm Hg, P = 0.003). In the whole cohort, a dose-dependent increase in systolic BP was observed according to the number of at-risk genotypes (0: 129.8 mm Hg; 1: 133.0 mm Hg; 2: 149.3 mm Hg, P = 0.02). Single nucleotide polymorphisms rs3754777 (STK39) and rs1468326 (WNK1) were associated with hypertension and BP in our multicenter Belgian case-control study, which supports the role of STK39 and WNK1 as potential hypertension susceptibility genes. Replication in different clinical settings and study of other candidate loci belonging to the same molecular pathway is warranted.

OBJECTIVE: Pheochromocytomas and paragangliomas (PPGL) are relatively rare and mostly benign tumours. Approximately 10% of PPGL are malignant, as defined by the presence of metastases, i.e chromaffin tissue at a location that usually does not contain chromaffin cells. However, up to 35% of tumours in patients carrying an SDHB mutation appears to be malignant. Nowadays, no reliable marker allows to predict whether a PPGL is, or will become malignant. In addition, there are no curative treatments if metastases occur. The aim of the present study was to dentify genetic markers allowing to distinguish benign from malignant tumours. DESIGN AND METHOD: An mRNA expression array was performed on benign and malignant PPGL. The genes showing a different expression between the benign and malignant tumours were selected to be confirmed and validated by qRT-PCR. Finally, the remaining genes were stained by immunohistochemistry on Tissue MicroArray including a large series of PPGL. RESULTS: Forty benign and 12 malignant PPGL were investigated for differences in mRNA expression with Affymetrix arrays. Expression data were normalized according to Affymetrix recommendations. Then, using Pomelo II (http://pomelo2.bioinfo.cnio.es/), a Limma t-test was performed, to assess which genes were differentially expressed between benign and malignant PPGL. First, a non-clustered analysis was performed and 10 genes with a False Discovery Rate (FDR) below 0.05 and a relative overexpression ratio of at least 4 were found, including Interleukin 13 Receptor alpha 2 (IL13RA2) and Monooxygenase DBH-like 1 (MOXD1). Secondly, a supervised cluster analysis was performed (based on HIF target genes), resulting in 2 groups, which were both investigated for differences in mRNA expression between benign and malignant tumours. Five genes showed an FDR below 0.01 and were overexpressed in malignant tumours with a ratio higher than 4, including Contactin 4 (CNTN4), Iroquois Homeobox 3 (IRX3), and Sulfatase 2 (S