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The epidermal growth factor receptor (EGFR) is frequently mutated in human cancer, most notably non-small-cell lung cancer and glioblastoma. While many frequently occurring EGFR mutations are known to confer constitutive EGFR activation, the situation is less clear for rarely detected variants. In fact, more than 1000 distinct EGFR mutations are listed in the Catalogue of Somatic Mutations in Cancer (COSMIC), but for most of them, the functional consequence is unknown. To identify additional, previously unknown activating mutations in EGFR, we screened a randomly mutated EGFR library for constitutive EGFR phosphorylation using a recently developed high-throughput approach termed PhosphoFlowSeq. Enrichment of the well-known activating mutations S768I, T790M, and L858R validated the experimental approach. Importantly, we also identified the activating mutations S442I and L658Q located in the extracellular and transmembrane domains of EGFR, respectively. To the best of our knowledge, neither S442I nor L658Q has been associated with an activating phenotype before. However, both have been detected in cancer samples. Interestingly, molecular dynamics (MD) simulations suggest that the L658Q mutation located in the hydrophobic transmembrane region forms intermolecular hydrogen bonds, thereby promoting EGFR dimerization and activation. Based on these findings, we screened the COSMIC database for additional hydrophilic mutations in the EGFR transmembrane region and indeed detected moderate constitutive activation of EGFR-G652R. Together, this study demonstrates that unbiased screening for activating mutations in EGFR not only yields well-established substitutions located in the kinase domain but also activating mutations in other regions of EGFR, including the extracellular and transmembrane domains.

Purpose: In many children with cancer and characteristics suggestive of a genetic predisposition syndrome, the genetic cause is still unknown. We studied the yield of pathogenic mutations by applying whole-exome sequencing on a selected cohort of children with cancer.Experimental Design: To identify mutations in known and novel cancer-predisposing genes, we performed trio-based whole-exome sequencing on germline DNA of 40 selected children and their parents. These children were diagnosed with cancer and had at least one of the following features: (1) intellectual disability and/or congenital anomalies, (2) multiple malignancies, (3) family history of cancer, or (4) an adult type of cancer. We first analyzed the sequence data for germline mutations in 146 known cancer-predisposing genes. If no causative mutation was found, the analysis was extended to the whole exome.Results: Four patients carried causative mutations in a known cancer-predisposing gene: TP53 and DICER1 (n = 3). In another 4 patients, exome sequencing revealed mutations causing syndromes that might have contributed to the malignancy (EP300-based Rubinstein–Taybi syndrome, ARID1A-based Coffin–Siris syndrome, ACTB-based Baraitser–Winter syndrome, and EZH2-based Weaver syndrome). In addition, we identified two genes, KDM3B and TYK2, which are possibly involved in genetic cancer predisposition.Conclusions: In our selected cohort of patients, pathogenic germline mutations causative or likely causative of the cancer phenotype were found in 8 patients, and two possible novel cancer-predisposing genes were identified. Therewith, our study shows the added value of sequencing beyond a cancer gene panel in selected patients, to recognize childhood cancer predisposition. Clin Cancer Res; 24(7); 1594–603. ©2018 AACR.

Supplementary Table S1 - Cancer gene panel Supplementary Table S2 - Patients with multiple malignancies Supplementary Table S3 - Tumor types of index patients Supplementary Table S4 - Candidate genes Supplementary Table S5 - Overview of clinical features and mutations found in category 1 (ID and/or congenital anomalies) Supplementary Table S6 - Overview of clinical features and mutations found in category 2 (cancer twice) Supplementary Table S7 - Overview of clinical features and mutations found in category 3 (family history) Supplementary Table S8 - Overview of clinical features and mutations found in category 4 (adult type of cancer) Supplementary Table S9 - Overview of clinical features and mutations found in category 5 (multiple reasons for inclusion) Supplementary Figure S1 - Detection of mosaic mutation in ARID1A Supplementary Figure S2 - Family tree of case #04 Supplementary Figure S3 - Family tree of case #05 Supplementary Figure S4 - Family tree of case #07 Supplementary Figure S5 - Family tree of case #10 Supplementary Figure S6 - Family tree of case #12 Supplementary Figure S7 - Family tree of case #17 Supplementary Figure S8 - Family tree of case #21 Supplementary Figure S9 - Family tree of case #22 Supplementary Figure S10 - Family tree of case #24 Supplementary Figure S11 - Family tree of case #27 Supplementary Figure S12 - Family tree of case #28 Supplementary Figure S13 - Family tree of case #29 Supplementary Figure S14 - Family tree of case #34 Supplementary Figure S15 - Family tree of case #36 Supplementary Figure S16 - Family tree of case #39

This file contains all mutations identified in all patients.

Secretin-stimulated pancreatic juice (PJ), collected from the duodenum, presents a valuable biomarker source for the (earlier) detection of pancreatic cancer (PC). Here, we evaluate the feasibility and performance of shallow sequencing to detect copy number variations (CNVs) in cell-free DNA (cfDNA) from PJ for PC detection. First, we confirmed the feasibility of shallow sequencing in PJ (n = 4), matched plasma (n = 3) and tissue samples (n = 4, microarray). Subsequently, shallow sequencing was performed on cfDNA from PJ of 26 cases (25 sporadic PC, 1 high-grade dysplasia) and 19 controls with a hereditary or familial increased risk of PC. 40 of the 45 PJ samples met the quality criteria for cfDNA analysis. Nine individuals had an 8q24 gain (oncogene MYC; 23%; eight cases (33%) and one control (6%), p = 0.04); six had both a 2q gain (STAT1) and 5p loss (CDH10; 15%; four cases (7%) and two controls (13%), p = 0.72). The presence of an 8q24 gain differentiated the cases and controls, with a sensitivity of 33% (95% CI 16–55%) and specificity of 94% (95% CI 70–100%). The presence of either an 8q24 or 2q gain with a 5p loss was related to a sensitivity of 50% (95% CI 29–71%) and specificity of 81% (95% CI 54–96%). Shallow sequencing of PJ is feasible. The presence of an 8q24 gain in PJ shows promise as a biomarker for the detection of PC. Further research is required with a larger sample size and consecutively collected samples in high-risk individuals prior to implementation in a surveillance cohort.

BACKGROUND: Neurofibromatosis type 1 (NF1) is a multisystem genetic disorder, predisposing development of benign and malignant tumours. Given the oncogenic potential, long-term surveillance is important in patients with NF1. Proposals for NF1 care and its specific manifestations have been developed, but lack integration within routine care. This guideline aims to assimilate available information on NF1 associated tumours (based on evidence and/or expert opinion) to assist healthcare professionals in undertaking tumour surveillance of NF1 individuals. METHODS: By comprehensive literature review, performed March 18th 2020, guidelines were developed by a NF1 expert group and patient representatives, conversant with clinical care of the wide NF1 disease spectrum. We used a modified Delphi procedure to overcome issues of variability in recommendations for specific (national) health care settings, and to deal with recommendations based on indirect (scarce) evidence. FINDINGS: We defined proposals for personalised and targeted tumour management in NF1, ensuring appropriate care for those in need, whilst reducing unnecessary intervention. We also incorporated the tumour-related psychosocial and quality of life impact of NF1. INTERPRETATION: The guideline reflects the current care for NF1 in Europe. They are not meant to be prescriptive and may be adjusted to local available resources at the treating centre, both within and outside EU countries. FUNDING: This guideline has been supported by the European Reference Network on Genetic Tumour Risk Syndromes (ERN GENTURIS). ERN GENTURIS is funded by the European Union. DGE is supported by the Manchester NIHRBiomedical Research Centre (IS-BRC-1215-20007). ispartof: ECLINICALMEDICINE vol:56 ispartof: location:England status: published

Background and Aims: In high-risk individuals (HRIs), we aimed to assess the cumulative incidence of intraductal papillary mucinous neoplasms (IPMNs) and compare IPMN growth, neoplastic progression rate, and the value of growth as predictor for neoplastic progression to these in sporadic IPMNs. Methods: We performed annual surveillance of Dutch HRIs, involving carriers of germline pathogenic variants (PVs) and PV-negative familial pancreatic cancer kindreds. HRIs with IPMNs were compared with Italian individuals without familial risk under surveillance for sporadic IPMNs. Results: A total of 457 HRIs were followed for 48 (range 2–172) months; the estimated cumulative IPMN incidence was 46% (95% confidence interval, 28%–64%). In comparison with 442 control individuals, IPMNs in HRIs were more likely to grow ≥2.5 mm/y (31% vs 7%; P < .001) and develop worrisome features (32% vs 19%; P = .010). PV carriers with IPMNs more often displayed neoplastic progression (n = 3 [11%] vs n = 6 [1%]; P = .011), while familial pancreatic cancer kindreds did not (n = 0 [0%]; P = 1.000). The malignancy risk in a PV carrier with an IPMN was 23% for growth rates ≥2.5 mm/y (n = 13), 30% for ≥5 mm/y (n = 10), and 60% for ≥10 mm/y (n = 5). Conclusions: The cumulative incidence of IPMNs in HRIs is higher than previously reported in the general population. Compared with sporadic IPMNs, they have an increased growth rate. PV carriers with IPMNs are suggested to be at a higher malignancy risk. Intensive follow-up should be considered for PV carriers with an IPMN growing ≥2.5 mm/y, and surgical resection for those growing ≥5 mm/y.

Recognizing a tumor predisposition syndrome (TPS) in a child with cancer is of clinical relevance. Earlier we developed a screening tool to increase diagnostic accuracy and clinical efficiency of identifying TPSs in children with cancer. Here we report on the value of this tool in clinical practice. TuPS is a prospective, observational, multi-center study including children newly diagnosed with cancer from 2016 to 2019 in the Netherlands. Children in whom a TPS had been diagnosed before the cancer diagnosis were excluded. The screening tool consists of a checklist, 2D and 3D photographic series and digital assessment of these by a clinical geneticist. If a TPS was suspected, the patient was assessed positive and referred for routine genetic consultation. Primary aim was to assess the clinical value of this new screening tool. Of the 363 included patients, 57% (208/363) were assessed positive. In 15% of patients (32/208), the 2D photographic series with (n = 12) or without (n = 20) 3D photographs were decisive in the positive assessment. In 2% (4/208) of positive assessed patients, a TPS was diagnosed, and in an additional 2% (4/208) a germline variant of uncertain significance was found. Thirty-five negatively assessed patients were evaluated through routine genetic consultation as controls, in none a TPS was detected. Using the screening tool, 57% of the patients were assessed as suspected for having a TPS. No false negative results were identified in the negative control group in the clinical care setting. The observed prevalence of TPS was lower than expected, due to selection bias in the cohort. Supplementary Information The online version contains supplementary material available at 10.1007/s10689-021-00237-1.

Dihydrofolate reductase (DHFR) is a critical enzyme in folate metabolism that reduces folic acid to dihydrofolic and tetrahydrofolic acid and provides an important target for antineoplastic, antimicrobial, and anti-inflammatory drugs. Defective DHFR activity leads to megaloblastic anemia syndrome combined with severe cerebral folate deficiency, and cerebral tetrahydrobiopterin deficiency due to a germ line missense mutation in DHFR has been reported.1,2 Folate represents a large family of water-soluble vitamins that play an important role in DNA synthesis, repair, and transmethylation pathways.3 Folate is also a substrate for purine and thymidine synthesis and a methyl donor for homocysteine to methionine conversion, with low folate status being reflected by elevated plasma homocysteine concentrations.4 Cerebral tetrahydrobiopterin is required for the formation of dopamine, serotonin, and norepinephrine and the hydroxylation of aromatic amino acids as a link to neurodevelopmental symptoms.

ObjectiveWe aimed to determine the long-term yield of pancreatic cancer surveillance in hereditary predisposed high-risk individuals.DesignFrom 2006 to 2019, we prospectively enrolled asymptomatic individuals with an estimated 10% or greater lifetime risk of pancreatic ductal adenocarcinoma (PDAC) after obligatory evaluation by a clinical geneticist and genetic testing, and subjected them to annual surveillance with both endoscopic ultrasonography (EUS) and MRI/cholangiopancreatography (MRI/MRCP) at each visit.Results366 individuals (201 mutation-negative familial pancreatic cancer (FPC) kindreds and 165 PDAC susceptibility gene mutation carriers; mean age 54 years, SD 9.9) were followed for 63 months on average (SD 43.2). Ten individuals developed PDAC, of which four presented with a symptomatic interval carcinoma and six underwent resection. The cumulative PDAC incidence was 9.3% in the mutation carriers and 0% in the FPC kindreds (pConclusionThe diagnostic yield of PDAC was substantial in established high-risk mutation carriers, but non-existent in the mutation-negative proven FPC kindreds. Nevertheless, timely identification of resectable lesions proved challenging despite the concurrent use of two imaging modalities, with EUS outperforming MRI/MRCP. Overall, surveillance by imaging yields suboptimal results with a clear need for more sensitive diagnostic markers, including biomarkers.

Objective: In the Netherlands a nationwide guideline was introduced in 2016, which recommended routine Lynch syndrome screening (LSS) for all women with endometrial cancer (EC)

To replace kidney function, peritoneal dialysis (PD) utilizes hyperosmotic PD fluids with specific physico-chemical properties. Their composition induces progressive damage of the peritoneum, leading to vasculopathies, decline of membrane function, and PD technique failure. Clinically used PD fluids differ in their composition but still remain bioincompatible. We mapped the molecular pathomechanisms in human endothelial cells induced by the different characteristics of widely used PD fluids by proteomics. Of 7894 identified proteins, 3871 were regulated at least by 1 and 49 by all tested PD fluids. The latter subset was enriched for cell junction-associated proteins. The different PD fluids individually perturbed proteins commonly related to cell stress, survival, and immune function pathways. Modeling two major bioincompatibility factors of PD fluids, acidosis, and glucose degradation products (GDPs) revealed distinct effects on endothelial cell function and regulation of cellular stress responses. Proteins and pathways most strongly affected were members of the oxidative stress response. Addition of the antioxidant and cytoprotective additive, alanyl-glutamine (AlaGln), to PD fluids led to upregulation of thioredoxin reductase-1, an antioxidant protein, potentially explaining the cytoprotective effect of AlaGln. In conclusion, we mapped out the molecular response of endothelial cells to PD fluids, and provided new evidence for their specific pathomechanisms, crucial for improvement of PD therapies.

Neurofibromatosis type 1 (NF1) and Legius syndrome (LS) are caused by inactivating variants in NF1 and SPRED1. NF1 encodes neurofibromin (NF), a GTPase activating protein (GAP) for RAS, that interacts with the SPRED1 product, Sprouty-related protein with an EVH (Ena/Vasp homology) domain 1 (SPRED1). Establishing a clinical and molecular diagnosis of NF1 or LS can be challenging due to the phenotypic diversity, the size and complexity of the NF1 and SPRED1 loci and uncertainty over the effects of variants on pre-mRNA splicing and NF/SPRED1 function. The purpose of this work was to improve NF1 and SPRED1 variant classification. To help establish the pathogenicity of NF1 and SPRED1 variants identified in individuals with NF1 or LS, we employed 4 assays: (i) analysis of patient RNA by RT-PCR; (ii) in vitro exon trap analysis of NF1 pre-mRNA splicing; (iii) in vitro analysis of NF RAS GAP activity; and (iv) in vitro analysis of the NF-SPRED1 interaction. In 69/105 (66%) cases we obtained evidence to support variant pathogenicity according to American College of Medical Genetics guidelines, demonstrating the utility of functional approaches for NF1 and SPRED1 variant classification and NF and LS diagnostics.

In high-risk individuals participating in a pancreatic cancer surveillance program, worrisome features warrant for intensified surveillance or, occasionally, surgery. Our objectives were to determine the patient-reported burden of intensified surveillance and/or surgery, and to assess post-operative quality of life and opinion of surgery. Participants in our pancreatic cancer surveillance program completed questionnaires including the Cancer Worry Scale (CWS) and the Hospital Anxiety and Depression Scale (HADS). For individuals who underwent intensified surveillance, questionnaires before, during, and ≥ 3 weeks after were analyzed. In addition, subjects who underwent intensified surveillance in the past 3 years or underwent surgery at any time, were invited for an interview, that included the Short-Form 12 (SF-12). A total of 31 high-risk individuals were studied. During the intensified surveillance period, median CWS scores were higher (14, IQR 7), as compared to before (12, IQR 9, P = 0.007) and after (11, IQR 7, P = 0.014), but eventually returned back to baseline (P = 0.823). Median HADS scores were low: 5 (IQR 6) for anxiety and 3 (IQR 5) for depression, and they were unaffected by the intensified surveillance period. Of the 10 operated patients, 1 (10%) developed diabetes and 7 (70%) pancreatic exocrine insufficiency. The interviews yielded median quality-of-life scores comparable to the general population. Also, after surgery, patients’ attitudes towards surveillance were unchanged (5/10, 50%) or became more positive (4/10, 40%). Although patients were aware of the (sometimes benign) pathological outcome, when asked if surgery had been justified, only 20% (2/10) disagreed, and all would again have chosen to undergo surgery. In conclusion, in individuals at high risk for pancreatic cancer, intensified surveillance temporarily increased cancer worries, without affecting general anxiety or depression. Although pancreatic surgery led to substantial co-morbidity, quality of life was similar to the general population, and surgery did not negatively affect the attitude towards surveillance. Electronic supplementary material The online version of this article (10.1007/s10689-020-00171-8) contains supplementary material, which is available to authorized users.

Western blotting is widely used for protein identification and quantification in research applications, but different protein species, resulting from alternative splicing and post-translational modifications, can often only be detected individually by two-dimensional gel electrophoresis and immunodetection by Western blotting (2D-WB). The additional separation by isoelectric focusing enables the detection of different protein species with the same specific antibody. Reliable assignment of signals from antibody-based detection to the total protein spot pattern of the original gel image is a challenge in 2D-WB, often resulting in ambiguous results. We therefore propose a reliable strategy for assignment of antibody signals from 2D-WB to the total protein spot pattern, using an imaging workflow in combination with a straightforward and easily reproducible image alignment strategy. The strategy employs vector-based alignment of protein spots and image contours in a stepwise manner. Our workflow is compatible with various protein visualization techniques, including prelabeling of proteins and poststaining of gels and membranes, as well as with chemiluminescent and fluorescent detection of bound antibody. Here, we provide a detailed description of potential applications and benefits of our workflow. We use experimental test settings with gold-standard stressors in combination with multiple staining and detection methods, as well as spike-in recombinant proteins. Our results demonstrate reliable attribution of signals to very similar heat shock proteins, phosphorylation patterns, and global analysis of proteins modified with O-linked N-acetylglucosamine (O-GlcNAc).

Introduction: The revised Dutch colorectal cancer guideline (2014), led to an overall decrease in preoperative radiotherapy (RT) use. This study evaluates hospital variation in RT use for resectable rectal cancer and the influence of guideline revision, including the nationwide impact of changing RT application on short term outcomes.Methods: Data of surgically resected rectal cancer patients registered in the Dutch ColoRectal Audit were extracted between 2011 and 2017. Patients were divided into groups based on time of guideline revision (= 2014). Primary outcome was guideline adherence at hospital level regarding RT application, stratified for three stage groups. Secondary outcomes included positive circumferential resection (CRM+) and 30-day complicated postoperative course.Results: The groups consisted of 7364 and 12,057 patients, respectively. In total, 6772 patients did not receive RT (17.6% (= 2014), p < 0.001). The largest increase of surgery alone was observed for cT1-2N0 stage rectal cancer (35.1% vs. 91.8%, p < 0.001), with a substantial decrease in hospital variation (IQR 22.2-50.0% vs. IQR 87.6-98.0%). For cT1-3N1MRF-stage rectal cancer, a substantial amount of hospital variation in short course RT remained after guideline revision (IQR 26.8-54.1% vs. IQR 26.2-50.0%). A significant decrease in CRMthorn (5.8% vs. 4.2%, p < 0.001) and complicated course (22.5% vs. 18.5%, p < 0.001) was observed.Conclusions: Radiotherapy for early-stage rectal cancer was uniformly abandoned after guideline revision, while substantial hospital variation remained for intermediate risk resectable rectal cancer in the Netherlands. The substantial nationwide decrease in the use of RT for rectal cancer treatment did not negatively impact CRM involvement. (C) 2020 Elsevier Ltd, BASO similar to The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.

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Pre-test counseling about multigene panel testing involves many uncertainties. Ideally, counselees are informed about uncertainties in a way that enables them to make an informed decision about panel testing. It is presently unknown whether and how uncertainty is discussed during initial cancer genetic counseling. We therefore investigated whether and how counselors discuss and address uncertainty, and the extent of shared decision-making (SDM), and explored associations between counselors’ communication and their characteristics in consultations on panel testing for cancer. For this purpose, consultations of counselors discussing a multigene panel with a simulated patient were videotaped. Simulated patients represented a counselee who had had multiple cancer types, according to a script. Before and afterwards, counselors completed a survey. Counselors’ uncertainty expressions, initiating and the framing of expressions, and their verbal responses to scripted uncertainties of the simulated patient were coded by two researchers independently. Coding was done according to a pre-developed coding scheme using The Observer XT software for observational analysis. Additionally, the degree of SDM was assessed by two observers. Correlation and regression analyses were performed to assess associations of communicated uncertainties, responses and the extent of SDM, with counselors’ background characteristics. In total, twenty-nine counselors, including clinical geneticists, genetic counselors, physician assistants-in-training, residents and interns, participated of whom working experience varied between 0 and 25 years. Counselors expressed uncertainties mainly regarding scientific topics (94%) and on their own initiative (95%). Most expressions were framed directly (77%), e.g. We don’t know, and were emotionally neutral (59%; without a positive/negative value). Counselors mainly responded to uncertainties of the simulated patient by explicitly referring to the uncertainty (69%), without providing space for further disclosure (66%). More experienced counselors provided less space to further disclose uncertainty (p

Background & Aims Patients with Lynch syndrome are offered the same colorectal cancer (CRC) surveillance programs (colonoscopy every 2 years), regardless of the pathogenic DNA mismatch repair gene variant the patient carries. We aimed to assess the yield of surveillance for patients with these variants in MLH1, MSH2, MSH6, and PMS2. Methods We analyzed data on colonoscopy surveillance, including histopathology analysis, from all patients diagnosed with Lynch syndrome (n = 264) at a single center. We compared the development of (advanced) adenomas and CRC among patients with pathogenic variants in the DNA mismatch repair genes MLH1 (n = 55), MSH2 (n = 44), MSH6 (n = 143), or PMS2 (n = 22) over 1836 years of follow-up (median follow-up of 6 years per patient). Results At first colonoscopy, CRC was found in 8 patients. During 916 follow-up colonoscopies, CRC was found in 9 patients. No CRC was found in patients with variants in MSH6 or PMS2 over the entire follow-up period. There were no significant differences in the number of colonoscopies with adenomas or advanced adenomas among the groups. The median time of adenoma development was 3 years (IQR, 2–6 years). There were no significant differences in time to development of adenoma. However, patients with variants in MSH6 had a significant longer time to development of advanced neoplasia (advanced adenoma or CRC) than patients in the other groups. Six carriers died during follow up (5 from cancer, of which 3 from pancreatic cancer). Conclusions No CRC was found during follow-up of patients with Lynch syndrome carrying pathogenic variants in MSH6; advanced neoplasia developed over shorter follow-up time periods in patients with pathogenic variants in MLH1 or MSH2. The colonoscopy interval for patients with pathogenic variants in MSH6 might be increased to 3 years from the regular 2-year interval.

Modifications of RNA, collectively called the "epitranscriptome", might provide novel biomarkers and innovative targets for interventions in geroscience but are just beginning to be studied in the context of ageing and stress resistance. RNA modifications modulate gene expression by affecting translation initiation and speed, miRNA binding, RNA stability, and RNA degradation. Nonetheless, the precise underlying molecular mechanisms and physiological consequences of most alterations of the epitranscriptome are still only poorly understood. We here systematically review different types of modifications of rRNA, tRNA and mRNA, the methodology to analyze them, current challenges in the field, and human disease associations. Furthermore, we compiled evidence for a connection between individual enzymes, which install RNA modifications, and lifespan in yeast, worm and fly. We also included resistance to different stressors and competitive fitness as search criteria for genes potentially relevant to ageing. Promising candidates identified by this approach include RCM1/NSUN5, RRP8, and F33A8.4/ZCCHC4 that introduce base methylations in rRNA, the methyltransferases DNMT2 and TRM9/ALKBH8, as well as factors involved in the thiolation or A to I editing in tRNA, and finally the m

Background & Aims: Lynch syndrome is a form of hereditary colorectal cancer (CRC) caused by pathogenic germline variants (PV) in DNA mismatch repair (MMR) genes. Currently, many Western countries perform universal immunohistochemistry testing on CRC to increase the identification of Lynch syndrome patients and their relatives. For a clear understanding of health benefits and costs, data on its outcomes are required: proportions of Lynch syndrome, sporadic MMR-deficient (MMRd) cases, and unexplained MMRd cases. Methods: Ovid Medline, Embase, and Cochrane CENTRAL were searched for studies reporting on universal MMR immunohistochemistry, followed by MMR germline analysis, until March 20, 2020. Proportions were calculated, subgroup analyses were performed based on age and diagnostics used, and random effects meta-analyses were conducted. Quality was assessed using the Joanna Briggs Critical Appraisal Tool for Prevalence Studies. Results: Of 2723 identified articles, 56 studies covering 58,580 CRCs were included. In 6.22% (95% CI, 5.08%–7.61%; I2 = 96%) MMRd was identified. MMR germline PV was present in 2.00% (95% CI, 1.59%–2.50%; I2 = 92%), ranging from 1.80% to 7.27% based on completeness of diagnostics and age restriction. Immunohistochemistry outcomes were missing in 11.81%, and germline testing was performed in 76.30% of eligible patients. In 7 studies, including 6848 CRCs completing all diagnostic stages, germline PV and biallelic somatic MMR inactivation were found in 3.01% and 1.75%, respectively; 0.61% remained unexplained MMRd. Conclusions: Age, completeness, and type of diagnostics affect the percentage of MMR PV and unexplained MMRd percentages. Complete diagnostics explain almost all MMRd CRCs, reducing the amount of subsequent multigene panel testing. This contributes to optimizing testing and surveillance in MMRd CRC patients and relatives.

The 2-oxoglutarate dehydrogenase-like (OGDHL) protein is a rate-limiting enzyme in the Krebs cycle that plays a pivotal role in mitochondrial metabolism. OGDHL expression is restricted mainly to the brain in humans. Here, we report nine individuals from eight unrelated families carrying bi-allelic variants in OGDHL with a range of neurological and neurodevelopmental phenotypes including epilepsy, hearing loss, visual impairment, gait ataxia, microcephaly, and hypoplastic corpus callosum. The variants include three homozygous missense variants (p.Pro852Ala, p.Arg244Trp, and p.Arg299Gly), three compound heterozygous single-nucleotide variants (p.Arg673Gln/p.Val488Val, p.Phe734Ser/p.Ala327Val, and p.Trp220Cys/p.Asp491Val), one homozygous frameshift variant (p.Cys553Leufs∗16), and one homozygous stop-gain variant (p.Arg440Ter). To support the pathogenicity of the variants, we developed a novel CRISPR-Cas9-mediated tissue-specific knockout with cDNA rescue system for dOgdh, the Drosophila ortholog of human OGDHL. Pan-neuronal knockout of dOgdh led to developmental lethality as well as defects in Krebs cycle metabolism, which was fully rescued by expression of wild-type dOgdh. Studies using the Drosophila system indicate that p.Arg673Gln, p.Phe734Ser, and p.Arg299Gly are severe loss-of-function alleles, leading to developmental lethality, whereas p.Pro852Ala, p.Ala327Val, p.Trp220Cys, p.Asp491Val, and p.Arg244Trp are hypomorphic alleles, causing behavioral defects. Transcript analysis from fibroblasts obtained from the individual carrying the synonymous variant (c.1464T>C [p.Val488Val]) in family 2 showed that the synonymous variant affects splicing of exon 11 in OGDHL. Human neuronal cells with OGDHL knockout exhibited defects in mitochondrial respiration, indicating the essential role of OGDHL in mitochondrial metabolism in humans. Together, our data establish that the bi-allelic variants in OGDHL are pathogenic, leading to a Mendelian neurodevelopmental disease in humans.

Rationale: Patients with chronic kidney disease (CKD) have an exceedingly high cardiovascular risk; which further increases in patients on peritoneal dialysis (PD). The pathophysiological role of reactive metabolites accumulating in CKD such as glucose degradation products (GDP) is uncertain. Objective: Delineating the impact of GDP present in PD fluids in accelerated vasculopathy development in patients with CKD. Methods and Results: Omental and parietal peritoneal tissues were obtained from 107 children with CKD before dialysis and 90 children on chronic PD with PD fluids containing very low or high concentrations of GDP. Omental arterioles, protected from local PD fluid exposure by surrounding fat, were microdissected for multiomics analyses. High-GDP exposed omental arterioles exhibited 3-fold higher advanced glycation endproduct concentrations and upregulated genes involved in cell death/apoptosis and suppressed genes related to cell viability/survival, cytoskeleton organization, and immune response biofunctions. Vasculopathy-associated canonical pathways concordantly regulated on gene and protein level with high-GDP exposure included cell death/proliferation, apoptosis, cytoskeleton organization, metabolism and detoxification, cell junction signaling, and immune response. Parietal peritoneal arterioles of patients exposed to high-GDP fluids exhibited lumen narrowing compared to patients with CKD stage 5 (end-stage kidney disease) and patients on low-GDP PD, intima thickness was increased. Protein quantification verified increased proapoptotic activity and cytoskeleton disintegration, single-molecule-localization microscopy demonstrated arteriolar endothelial ZO-1 (zonula occludens-1) disruption. Absolute and per endoluminal surface length, arteriolar endothelial cell counts inversely correlated with GDP exposure, caspase-3, TGF (transforming growth factor)-β–induced pSMAD2/3 (phosphorylated SMAD2/3), interleukin-6, ZO-1 abundance, and lumen narrowing. In vitro, 3,4-dideoxyglucosone-3-ene reduced lamin-A/C and membrane ZO-1 assembly, increased pSMAD2/3, and ionic and 4 and 10 kDa permeability of arterial endothelial cells. Conclusions: Our findings indicate a fundamental role of GDP in PD-associated vasculopathy, exerted by endothelial cell junction and cytoskeleton disruption, and induction of apoptosis. They should redirect the focus of research and intervention on targeting reactive metabolite overload in CKD and PD. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT01893710.

Main RecommendationsESGE recommends that individuals with hereditary gastrointestinal polyposis syndromes should be surveilled in dedicated units that provide monitoring of compliance and endoscopic performance measures. Strong recommendation, moderate quality of evidence, level of agreement 90 %.ESGE recommends performing esophagogastroduodenoscopy, small-bowel examination, and/or colonoscopy earlier than the planned surveillance procedure if a patient is symptomatic. Strong recommendation, low quality of evidence, level of agreement 100 %.

Teaching experience at the University of Suffolk noted anecdotally that Black Asian and Minority Ethnic (BAME) students avoid discussing their identity, cultural heritage, norms and values, in lect...

Main RecommendationsESGE recommends that individuals with Lynch syndrome should be followed in dedicated units that practice monitoring of compliance and endoscopic performance measures.Strong recommendation, low quality evidence, level of agreement 100 %.ESGE recommends starting colonoscopy surveillance at the age of 25 years for MLH1 and MSH2 mutation carriers and at the age of 35 years for MSH6 and PMS2 mutation carriers.Strong recommendation, moderate quality evidence, level of agreement 100 %. ESGE recommends the routine use of high-definition endoscopy systems in individuals with Lynch syndrome. Strong recommendation, high quality evidence, level of agreement 100 %. ESGE suggests the use of chromoendoscopy may be of benefit in individuals with Lynch syndrome undergoing colonoscopy; however routine use must be balanced against costs, training, and practical considerations.Weak recommendation, moderate quality evidence, level of agreement 89 %.ESGE recommends definition of familial risk of colorectal cancer as the presence of at least two first-degree relatives with colorectal cancer or at least one first-degree relative with colorectal cancer before the age of 50 years.Strong recommendation, moderate quality evidence, level of agreement 92 %.ESGE recommends colonoscopy surveillance in first-degree relatives of colorectal cancer patients in families that fulfill the definition of familial risk of colorectal cancer.Strong recommendation, moderate quality evidence, level of agreement 100 %.

Drug resistance poses a major challenge for targeted cancer therapy. To be able to functionally screen large randomly mutated target gene libraries for drug resistance mutations, we developed a biochemically defined high-throughput assay termed PhosphoFlowSeq. Instead of selecting for proliferation or resistance to apoptosis, PhosphoFlowSeq directly analyzes the enzymatic activities of randomly mutated kinases, thereby reducing the dependency on the signaling network in the host cell. Moreover, simultaneous analysis of expression levels enables compensation for expression-based biases on a single cell level. Using EGFR and its kinase inhibitor erlotinib as a model system, we demonstrate that the clinically most relevant resistance mutation T790M is reproducibly detected at high frequencies after four independent PhosphoFlowSeq selection experiments. Moreover, upon decreasing the selection pressure, also mutations which only confer weak resistance were identified, including T854A and L792H. We expect that PhosphoFlowSeq will be a valuable tool for the prediction and functional screening of drug resistance mutations in kinases.

Background and Aims Patients with chronic kidney disease patients (CKD) have an exceedingly high cardiovascular risk. While vasculopathy is further accelerated during peritoneal dialysis (PD), the pathophysiological role of reactive metabolites such as glucose degradation products (GDP) is uncertain. Method Omental and parietal peritoneal tissues from 100 non-CKD individuals, 107 children with CKD5, 60 children treated with neutral pH, low GDP, and 30 children treated with acidic pH, high GDP PD fluids underwent standardized digital histomorphometry. Omental arterioles localized within the fat tissue, protected from direct PD fluid exposure were microdissected for multi-omics analysis. Key regulated pathways were validated by quantitative immunostaining, with localization microscopy in peritoneal tissues of matched cohorts and in vitro in human umbilical vein endothelial cells. Results Arterioles from children with CKD5 exhibited reduced lumen to vessel ratio (L/V) and reduced endothelial telomere length compared to non-CKD individuals; gene ontology analysis identified enrichment of arteriolar genes associated with nuclear telomere cap complex and focal adhesion. Pathway analysis of arteriolar cross-omics identified top canonical pathways including telomere extension by telomerase, actin cytoskeleton, integrin and tight junction signalling. Peritoneal vasculopathy progressed with PD vintage and was more pronounced with high versus low GDP exposure (p Quantitative validation in PD cohorts with similar PD vintage, dialytic glucose exposure and age (n=15 / group) verified increased proapoptotic activity and cytoskeleton disintegration with high-GDP exposure; single-molecule-localization microscopy demonstrated arteriolar endothelial zonula occludens-1 (ZO-1) disruption. Absolute and relative to endoluminal surface length, arteriolar endothelial cell counts were inversely correlated with GDP exposure, with apoptosis marker caspase-3, TGF-ß induced pSMAD2/3, interleukin-6, ZO-1 protein abundance and the degree of vasculopathy. In vitro, exposure to GDP 3,4-dideoxyglucosone-3-ene dose-dependently reduced nuclear endothelial lamin-A/C and membrane ZO-1 assembly. Transendothelial electrical resistance was decreased. ZO-1 and sealing tight junction claudin-5 protein abundance were decreased in cells after incubation with high GDP compared to low GDP PD fluid and culture media. On nanoscale level GDP reduced junction cluster formation in the membrane area. Conclusion Multi-omics analysis of omental arterioles from children without pre-existing vasculopathy and life-style related confounders identified key mechanisms of vascular aging in CKD5 and the major contribution of GDP to accelerated vasculopathy during PD, i.e. disruption of endothelial cell junctions and cytoskeleton and induction of apoptosis.

Background and Aims Reactive oxygen species (ROS) in the peritoneal cavity may result both from CKD and the specific composition of peritoneal dialysis fluids (PDF). Elevated cellular oxidative stress is defined as a cellular oxidant/antioxidant imbalance which impairs not only peritoneal cell viability but also contributes to progression of local and systemic PD-related pathomechanisms. So far only single targets or mediators of oxidative stress were investigated in mesothelial cells exposed to PD fluids. Here, we aim to analyze the broad impact and also identify individual targets of ROS during PD. Using the developed technique the anti-oxidative effect of alanyl-glutamine (AlaGln) supplementation of PDF was characterized on the proteome level. Method To establish a redox-proteomics workflow for studying oxidative stress in peritoneal mesothelial cells we used a gold-standard model of redox-stress (100 µm hydrogen peroxide (H2O2)) and PD-fluid induced stress. Levels of oxidative stress were first evaluated by intracellular ROS levels and superoxide dismutase activity. Oxidative stress levels induced by PDF were titrated to comparable levels of H2O2 treatment to be able to characterize redox modifications and the effect of addition of 8 mM AlaGln. To detect alterations of the redox proteome we adapted and refined an approach combining redox-sensitive isobaric mass tags and high-performance liquid chromatography coupled to mass spectrometry (LC/MS). We used a sequential combination of direct and indirect labeling of redox-sensitive cysteine residues. Results Exposure to PDF increased intracellular ROS production and accumulation as well as cell damage assessed by LDH-release compared to control cells. Cells exposed to AlaGln supplemented PDF showed less cell damage compared to PDF alone. Addition of AlaGln not only reduced the overall redox status (intracellular ROS and superoxide dismutase activity) but also led to different proteins being affected by redox modifications. The carefully optimized highly sensitive LC/MS-based redox proteomics workflow allowed identification of 5537 proteins of which 2614 contained a labeled cysteine. H2O2 treatment resulted in a shift of median oxidation from 11% under control conditions to 36%. While PDF alone increased the oxidation level to 31%, AlaGln supplemented PDF only led to 15% oxidation. Pathway analysis of proteins that changed their oxidation level >50% following the treatment were subjected to molecular pathway analysis revealing distinct differences. PDF exposure leads to regulation of general cell processes like regulation of glucokinase, RNA-binding and SUMOylation, addition of AlaGln regulated more specific signaling pathways for example fibrosis related pathways like TGF-ß and SMAD signaling. Conclusion Redox proteomics of peritoneal cells could represent a novel tool for the identification of mediators of uraemia and PD-induced pathomechanisms, and also to evaluate anti-oxidant pharmacological interventions to improve PD outcomes.

BackgroundPathogenic variants in the CDKN2A gene are generally associated with the development of melanoma and pancreatic ductal adenocarcinoma (PDAC), but specific genotype-phenotype correlations might exist and the extent of PDAC risk is not well established for many variants.MethodsUsing the Dutch national familial melanoma database, we identified all families with a pathogenic CDKN2A variant and investigated the occurrence of PDAC within these families. We also estimated the standardised incidence ratio and lifetime PDAC risk for carriers of a highly prevalent variant in these families.ResultsWe identified 172 families in which 649 individuals carried 15 different pathogenic variants. The most prevalent variant was the founder mutation c.225_243del (p16-Leiden, 484 proven carriers). Second most prevalent was c.67G>C (55 proven carriers). PDAC developed in 95 of 163 families (58%, including 373 of 629 proven carriers) harbouring a variant with an effect on the p16INK4a protein, whereas PDAC did not occur in the 9 families (20 proven carriers) with a variant affecting only p14ARF. In the c.67G>C families, PDAC occurred in 12 of the 251 (5%) persons at risk. The standardised incidence ratio was 19.1 (95% CI 8.3 to 33.6) and the cumulative PDAC incidence at age 75 years (lifetime risk) was 19% (95% CI 7.5% to 30.1%).ConclusionsOur results support the notion that pathogenic CDKN2A variants affecting the p16INK4a protein, including c.67G>C, are associated with increased PDAC risk and carriers of such variants should be offered pancreatic cancer surveillance. There is no clinical evidence that impairment of only the p14ARF protein leads to an increased PDAC risk.

The scientific data to guide the management of Peutz–Jeghers syndrome (PJS) are sparse. The available evidence has been reviewed and discussed by diverse medical specialists in the field of PJS to update the previous guideline from 2010 and formulate a revised practical guideline for colleagues managing PJS patients. Methods: Literature searches were performed using MEDLINE, Embase, and Cochrane. Evidence levels and recommendation strengths were assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE). A Delphi process was followed, with consensus being reached when ≥80% of the voting guideline committee members agreed. Recommendations and statements: The only recent guidelines available were for gastrointestinal and pancreatic management. These were reviewed and endorsed after confirming that no more recent relevant papers had been published. Literature searches were performed for additional questions and yielded a variable number of relevant papers depending on the subject addressed. Additional recommendations and statements were formulated. Conclusions: A decade on, the evidence base for recommendations remains poor, and collaborative studies are required to provide better data about this rare condition. Within these restrictions, multisystem, clinical management recommendations for PJS have been formulated.