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Emerging evidence suggests that ADHD is associated with increased risk for metabolic and cardiovascular (cardiometabolic) diseases. However, an understanding of the mechanisms underlying these associations is still limited. In this study we estimated the associations of polygenic scores (PGS) for ADHD with several cardiometabolic diseases and biomarkers. Furthermore, we investigated to what extent the PGS effect was influenced by direct and indirect genetic effects (i.e., shared familial effects). We derived ADHD-PGS in 50,768 individuals aged 18-90 years from the Dutch Lifelines Cohort study. Using generalised estimating equations, we estimated the association of PGS with cardiometabolic diseases, derived from self-report and several biomarkers measured during a physical examination. We additionally ran within-sibling PGS analyses, using fixed effects models, to disentangle direct effects of individuals' own ADHD genetic risk from confounding due to indirect genetic effects of relatives, as well as population stratification. We found that higher ADHD-PGS were statistically significantly associated with several cardiometabolic diseases (R-squared [R 2 ] range = 0.03-0.50%) and biomarkers (related to inflammation, blood pressure, lipid metabolism, amongst others) (R 2 range = 0.01-0.16%) (P < 0.05). Adjustment for shared familial factors attenuated the associations between ADHD-PGS and cardiometabolic outcomes (on average 56% effect size reduction), and significant associations only remained for metabolic disease. Overall our findings suggest that increased genetic liability for ADHD confers a small but significant risk increase for cardiometabolic health outcomes in adulthood. These associations were observable in the general population, even in individuals without ADHD diagnosis, and were partly explained by familial factors shared among siblings., Competing Interests: Competing interests EDR has served as a speaker for Shire Sweden AB, a Takeda Pharmaceutical Company outside of this work. HL reports receiving grants from Shire Pharmaceuticals; personal fees from and serving as a speaker for Medice, Shire/Takeda Pharmaceuticals and Evolan Pharma AB; all outside the submitted work. HL is editor-in-chief of JCPP Advances., (© 2024. The Author(s).)

Purpose: CHEK2 c.1100delC is associated with an increased breast cancer risk in women. While this variant is prevalent in the Netherlands (1% in the general population), knowledge of aetiology and prognosis of breast cancer and other tumours in CHEK2 c.1100delC carriers is lacking. The nationwide HEreditary Breast and Ovarian cancer study the Netherlands (Hebon) cohort aims to answer study questions in families with an increased risk of breast cancer and ovarian cancer. While initially focusing on BRCA1/2 -variant families, Hebon gradually expanded to include pathogenic variants in other genes associated with breast and/or ovarian cancer over time. This provides an excellent setting to establish a cohort to ultimately study the impact of CHEK2 c.1100delC on cancer risk prediction and surveillance, breast cancer treatment and prognosis., Participants: We invited all heterozygous and homozygous CHEK2 c.1100delC indexes and tested female relatives. 1802 women were included, of whom 1374 were heterozygotes and 938 were breast cancer cases. Pedigrees were collected from all clinical genetic departments. Furthermore, participants completed a detailed questionnaire on hormonal and lifestyle factors, family history, cancer diagnosis and treatment., Findings to Date: Mean age at study inclusion was 53 years. Linkage with the Netherlands Cancer Registry showed a younger age at diagnosis in homozygotes (mean age 41.7 years) and heterozygotes (47.9 years) than non-carriers (51.2 years). Furthermore, carriers were more often diagnosed with grade 2, oestrogen receptor-positive breast cancer and more often developed contralateral breast cancer than non-carriers. Most women consumed alcohol regularly and about half never smoked., Future Plans: Further data linkages with the Netherlands Cancer Registry will allow prospective follow-up and breast cancer risk assessment in unaffected women at the time of genetic testing, risk of contralateral breast cancer and survival in patients with breast cancer. Also, linkage with the nationwide network and registry of histopathology and cytopathology in The Netherlands (PALGA) allows us to retrieve tumour samples to study tumourigenesis., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY. Published by BMJ.)

Background and Aims: Familial hypercholesterolemia (FH) is a genetic disorder marked by high LDL cholesterol and an increased premature coronary artery disease (CAD) risk. Current dichotomous classification of LDL receptor gene (LDLR) variants may inadequately capture patient variability in LDL cholesterol levels and CAD risk. This study assessed a novel approach for determining LDLR variant severity using variant-specific LDL cholesterol percentiles., Methods: Participants of the Dutch FH cascade screening program were screened for 456 LDLR variants. For each LDLR variant carrier, a sex- and age-specific LDL cholesterol percentile was derived from the LDL cholesterol level measured at study entry, i.e. generally from the blood drawn for DNA analysis. These percentiles were used to calculate the mean LDL cholesterol percentile for each variant. Based on the variant-specific LDL cholesterol percentiles, carriers were grouped into the following LDL cholesterol strata: <75th, 75th-88th, 88th-92nd, 92nd-96.5th, 96.5th-98th, and ≥98th percentile. Additionally, variants were categorized into class 1 (LDLR deficient) and non-class 1 (often LDLR defective) variants. CAD risk between carriers in the different LDL cholesterol strata and non-carriers was compared using a Cox proportional hazard model., Results: Out of 35,067 participants, 12,485 (36 %) LDLR variant carriers (mean age 38.0 ± 20.0 years, 47.7 % male) were identified. Carriers had a 5-fold higher CAD risk compared with non-carriers. Hazard ratios for CAD increased gradually from 2.2 (95%CI 0.97-5.0) to 12.0 (95%CI 5.5-24.8) across the LDL cholesterol strata. A 7.3-fold and 3.9-fold increased CAD risk was observed in carriers of class 1 and non-class 1 LDLR variants, respectively., Conclusions: This study presents a refined approach for classifying LDLR variants based on their impact on LDL cholesterol levels, allowing for more precise, genotype-specific CAD risk estimation in FH patients compared with traditional methods., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: LFR is cofounder of Lipid Tools and reports speakers fee from Ultragenyx, Novartis, and Daiichi Sankyo. JJPK is part time CSO of New Amsterdam Pharma and part time CMO of Staten Biotech and a consultant to AgBio, Scribe, Cincor, CSL Behring, CiVi Biopharma, Draupnir, Esperion Therapeutics, Madrigal, Menarini, Omeicos, Silence Therapeutics, Sirnaomics, TTxD and North Sea Therapeutics. GKH reports research grants from the Netherlands Organization for Scientific Research (vidi 016.156.445), CardioVascular Research Initiative, European Union and the Klinkerpad fonds, institutional research support from Aegerion, Amgen, AstraZeneca, Eli Lilly, Genzyme, Ionis, Kowa, Pfizer, Regeneron, Roche, Sanofi, and The Medicines Company; speaker's bureau and consulting fees from Amgen, Aegerion, Sanofi, and Regeneron until April 2019 (fees paid to the academic institution); and part-time employment and stock holder of at Novo Nordisk A/S, Denmark since April 2019. ESGS has received ad-board/lecturing fees, paid to the institution, from: Amgen, Sanofi, Astra-Zeneca, Esperion, Daiichi Sankyo, NovoNordisk, Ionis/Akcea, Amarin. The other authors report no disclosures., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Germline data have become widely available in paediatric oncology since the introduction of paired tumour-germline sequencing. To guide best practice in cancer predisposition syndrome (CPS) diagnostics, we aimed to assess the diagnostic yield of extensive germline analysis compared with clinical selection-based genetic testing among all children with cancer., Methods: In this prospective diagnostic study, all children (aged 0-19 years) with newly diagnosed neoplasms treated in the Netherlands national centre, the Princess Máxima Center for Pediatric Oncology (Utrecht, Netherlands), between June 1, 2020, and July 31, 2022, were offered two approaches to identify CPSs. In a phenotype-driven approach, paediatric oncologists used the McGill Interactive Pediatric OncoGenetic Guidelines tool to select children for referral to a clinical geneticist, and for genetic testing. In a phenotype-agnostic approach, CPS gene panel sequencing (143 genes) was offered to all children. In children declining the research CPS gene panel, 49 CPS genes were still analysed as part of routine diagnostics by the pathologist. Children with a causative CPS identified before neoplasm diagnosis were excluded. The primary objective was to compare the number and type of patients diagnosed with a CPS between the two approaches., Findings: 1052 children were eligible for this study, of whom 733 (70%) completed both the phenotype-driven approach and received phenotype-agnostic CPS gene panel sequencing (143 genes n=600; 49 genes n=133). In 53 children, a CPS was identified: 14 (26%) were diagnosed by the phenotype-driven approach only, 22 (42%) by CPS gene sequencing only, and 17 (32%) by both approaches. In 27 (51%) of the 53 children, the identified CPS was considered causative for the child's neoplasm. Only one (4%) of the 27 causative CPSs was missed by the phenotype-driven approach and was identified solely by phenotype-agnostic CPS gene sequencing. In 26 (49%) children, a CPS with uncertain causality was identified, including 14 adult-onset CPSs. The CPSs with uncertain causality were mainly detected by the phenotype-agnostic approach (21 [81%] of 26)., Interpretation: Phenotype-driven genetic testing and phenotype-agnostic CPS gene panel sequencing were complementary. The phenotype-driven approach identified the most causative CPSs. CPS gene panel sequencing identified additional CPSs, many of those with uncertain causality, but some with clinical utility. We advise clinical evaluation for CPSs in all children with neoplasms. Phenotype-agnostic testing of all CPS genes is preferably conducted only in research settings and should be paired with counseling., Funding: Stichting Kinderen Kankervrij., Competing Interests: Declaration of interests We declare no competing interests., (Copyright © 2024 Elsevier Ltd. All rights reserved, including those for text and data mining, AI training, and similar technologies.)

Purpose: Female CHEK2 c.1100delC heterozygotes are eligible for additional breast surveillance because of an increased breast cancer risk. Increased risks for other cancers have been reported. We studied whether CHEK2 c.1100delC is associated with an increased risk for other cancers within these families., Methods: Including 10,780 individuals from 609 families, we calculated standardized incidence rates (SIRs) and absolute excess risk (AER, per 10,000 person-years) by comparing first-reported cancer derived from the pedigrees with general Dutch population rates from 1970 onward. Attained-age analyses were performed for sites in which significant increased risks were found. Considering the study design, we primarily focused on cancer risk in women., Results: We found significant increased risks of colorectal cancer (CRC; SIR = 1.43, 95% CI = 1.14-1.76; AER = 1.43) and hematological cancers (SIR = 1.32; 95% CI = 1.02-1.67; AER = 0.87). CRC was significantly more frequent from age 45 onward., Conclusion: A significantly increased risk of CRC, and hematological cancers in women was found, starting at a younger age than expected. Currently, colorectal surveillance starts at age 45 in high-risk individuals. Our results suggest that some CHEK2 c.1100delC families might benefit from this surveillance as well; however, further research is needed to determine who may profit from this additional colorectal surveillance., Competing Interests: Conflict of Interest The authors declare no conflicts of interest., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

This study investigated the neurodevelopmental impact of pathogenic adenomatous polyposis coli (APC) gene variants in patients with familial adenomatous polyposis (FAP), a cancer predisposition syndrome. We hypothesized that certain pathogenic APC variants result in behavioral-cognitive challenges. We compared 66 FAP patients (cases) and 34 unaffected siblings (controls) to explore associations between APC variants and behavioral and cognitive challenges. Our findings indicate that FAP patients exhibited higher Social Responsiveness Scale (SRS) scores, suggesting a greater prevalence of autistic traits when compared to unaffected siblings (mean 53.8 vs. 47.4, Wilcoxon p = 0.018). The distribution of SRS scores in cases suggested a bimodal pattern, potentially linked to the location of the APC variant, with scores increasing from the 5' to 3' end of the gene (Pearson's r = 0.33, p = 0.022). While we observed a trend toward lower educational attainment in cases, this difference was not statistically significant. This study is the first to explore the connection between APC variant location and neurodevelopmental traits in FAP, expanding our understanding of the genotype-phenotype correlation. Our results emphasize the importance of clinical assessment for autistic traits in FAP patients, shedding light on the potential role of APC gene variants in these behavioral and cognitive challenges., (© 2024 The Author(s). American Journal of Medical Genetics Part B: Neuropsychiatric Genetics published by Wiley Periodicals LLC.)

Background: Individual differences in susceptibility to developing asthma, a heterogeneous chronic inflammatory lung disease, are poorly understood. Whether genetics can predict asthma risk and how genetic variants modulate the complex pathophysiology of asthma are still debated., Aim: To build polygenic risk scores for asthma risk prediction and epigenomically link predictive genetic variants to pathophysiological mechanisms., Methods: Restricted polygenic risk scores were constructed using single nucleotide variants derived from genome-wide association studies and validated using data generated in the Rotterdam Study, a Dutch prospective cohort of 14 926 individuals. Outcomes used were asthma, childhood-onset asthma, adulthood-onset asthma, eosinophilic asthma and asthma exacerbations. Genome-wide chromatin analysis data from 19 disease-relevant cell types were used for epigenomic polygenic risk score partitioning., Results: The polygenic risk scores obtained predicted asthma and related outcomes, with the strongest associations observed for childhood-onset asthma (2.55 odds ratios per polygenic risk score standard deviation, area under the curve of 0.760). Polygenic risk scores allowed for the classification of individuals into high-risk and low-risk groups. Polygenic risk score partitioning using epigenomic profiles identified five clusters of variants within putative gene regulatory regions linked to specific asthma-relevant cells, genes and biological pathways., Conclusions: Polygenic risk scores were associated with asthma(-related traits) in a Dutch prospective cohort, with substantially higher predictive power observed for childhood-onset than adult-onset asthma. Importantly, polygenic risk score variants could be epigenomically partitioned into clusters of regulatory variants with different pathophysiological association patterns and effect estimates, which likely represent distinct genetically driven disease pathways. Our findings have potential implications for personalised risk mitigation and treatment strategies., Competing Interests: Conflict of interest: G. Brusselle has received fees for lectures from AstraZeneca, Boehringer Ingelheim, Chiesi, GlaxoSmithKline, Novartis and Sanofi Regeneron; and honoraria for participating on advisory boards from AstraZeneca, Boehringer Ingelheim, Chiesi, GlaxoSmithKline, Merck Sharp & Dohme, Novartis and Sanofi Regeneron. The remaining authors declare no conflicts of interest., (Copyright ©The authors 2024.)

Purpose: A healthy diet reduces the risk of non-alcoholic fatty liver disease (NAFLD) in the general population, especially in individuals who are genetically predisposed to NAFLD. Little is known in patients who suffered from a myocardial infarction (MI). We examined the interaction between diet quality and genetic predisposition in relation to NAFLD in post-MI patients., Methods: We included 3437 post-MI patients from the Alpha Omega Cohort. Diet quality was assessed with adherence to the Dutch Healthy Diet index 2015 (DHD15-index). A weighted genetic risk score (GRS) for NAFLD was computed using 39 genetic variants. NAFLD prevalence was predicted using the Fatty Liver Index. Prevalence ratios (PR) with 95% confidence intervals of DHD15-index and GRS in relation to NAFLD were obtained with multivariable Cox proportional hazards models. The interaction between DHD15-index and GRS in relation to NAFLD was assessed on an additive and multiplicative scale., Results: Patients had a mean age of 69 (± 5.5) years, 77% was male and 20% had diabetes. The DHD15-index ranged from 28 to 120 with a mean of 73. Patients with higher diet quality were less likely to suffer from NAFLD, with a PR of 0.76 (0.62, 0.92) for the upper vs lower quintile of DHD15-index. No association between the GRS and NAFLD prevalence was found (PR of 0.92 [0.76, 1.11]). No statistically significant interaction between the DHD15-index and GRS was observed., Conclusion: In Dutch post-MI patients, adherence to the Dutch dietary guidelines was associated with a lower prevalence of NAFLD, as assessed by the FLI. This association was present regardless of genetic predisposition in this older aged cohort., (© 2024. The Author(s).)

Small-Fiber Neuropathy (SFN) is a disorder of the peripheral nervous system, characterised by neuropathic pain; approximately 11% of cases are linked to variants in Voltage-Gated Sodium Channels (VGSCs). This study aims to broaden the genetic knowledge on painful SFN by applying Whole-Exome Sequencing (WES) in Early-Onset (EO) cases. A total of 88 patients from Italy (n = 52) and the Netherlands (n = 36), with a disease onset at age ≤ 45 years old and a Pain Numerical Rating Score ≥ 4, were recruited. After variant filtering and classification, WES analysis identified 142 potentially causative variants in 93 genes; 8 are Pathogenic, 15 are Likely Pathogenic, and 119 are Variants of Uncertain Significance. Notably, an enrichment of variants in transient receptor potential genes was observed, suggesting their role in pain modulation alongside VGSCs. A pathway analysis performed by comparing EO cases with 40 Italian healthy controls found enriched mutated genes in the "Nicotinic acetylcholine receptor signaling pathway". Targeting this pathway with non-opioid drugs could offer novel therapeutic avenues for painful SFN. Additionally, with this study we demonstrated that employing a gene panel of reported mutated genes could serve as an initial screening tool for SFN in genetic studies, enhancing clinical diagnostics.

Purpose: We examined the relation between diet quality, its components and kidney function decline in post-myocardial infarction (MI) patients, and we explored differences by genetic risk of chronic kidney disease (CKD)., Methods: We analysed 2169 patients from the Alpha Omega Cohort (aged 60-80 years, 81% male). Dietary intake was assessed at baseline (2002-2006) using a validated food-frequency questionnaire and diet quality was defined using the Dutch Healthy Diet Cardiovascular Disease (DHD-CVD) index. We calculated 40-months change in estimated glomerular filtration rate (eGFR, mL/min per 1.73m 2 ). We constructed a weighted genetic risk score (GRS) for CKD using 88 single nucleotide polymorphisms previously linked to CKD. Betas with 95%-confidence intervals (CIs) were obtained using multivariable linear regression models for the association between DHD-CVD index and its components and eGFR change, by GRS., Results: The average DHD-CVD index was 79 (SD 15) points and annual eGFR decline was 1.71 (SD 3.86) mL/min per 1.73 m 2 . The DHD-CVD index was not associated with annual eGFR change (per 1-SD increment in adherence score: -0.09 [95% CI -0.26,0.08]). Results for adherence to guidelines for red meat showed less annual eGFR decline (per 1-SD: 0.21 [0.04,0.38]), whereas more annual eGFR decline was found for legumes and dairy (per 1-SD: -0.20 legumes [-0.37,-0.04] and - 0.18 dairy [-0.34,-0.01]). Generally similar results were obtained in strata of GRS., Conclusion: The DHD-CVD index for overall adherence to Dutch dietary guidelines for CVD patients was not associated with kidney function decline after MI, irrespective of genetic CKD risk. The preferred dietary pattern for CKD prevention in CVD patients warrants further research., (© 2024. The Author(s).)

The association between circadian rhythms and diseases has been well established, while the association with mental health is less explored. Given the heritable nature of circadian rhythms, this study aimed to investigate the relationship between genes underlying circadian rhythms and mental health outcomes, as well as a possible gene-environment correlation for circadian rhythms. Polygenic scores (PGSs) represent the genetic predisposition to develop a certain trait or disease. In a sample from the Netherlands Twin Register ( N  = 14,021), PGSs were calculated for two circadian rhythm measures: morningness and relative amplitude (RA). The PGSs were used to predict mental health outcomes such as subjective happiness, quality of life, and depressive symptoms. In addition, we performed the same prediction analysis in a within-family design in a subset of dizygotic twins. The PGS for morningness significantly predicted morningness ( R 2  = 1.55%) and depressive symptoms ( R 2  = 0.22%). The PGS for RA significantly predicted general health ( R 2  = 0.12%) and depressive symptoms ( R 2  = 0.20%). Item analysis of the depressive symptoms showed that 4 out of 14 items were significantly associated with the PGSs. Overall, the results showed that people with a genetic predisposition of being a morning person or with a high RA are likely to have fewer depressive symptoms. The four associated depressive symptoms described symptoms related to decision-making, energy, and feeling worthless or inferior, rather than sleep. Based on our findings future research should include a substantial role for circadian rhythms in depression research and should further explore the gene-environment correlation in circadian rhythms., Competing Interests: Conflict Of Interest StatementThe authors have no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

The uptake of genetic counseling and predictive genetic testing by family members at risk for hereditary tumor syndromes is generally below 50%. To address this issue, a new guideline was introduced in the Netherlands in 2019 that aims to improve the sharing of information within families. In addition to cascade screening supported by follow-up telephone calls with the proband, municipal records were accessed to allow the geneticist to contact at-risk family members directly. We evaluated this procedure in 32 families with a (likely) pathogenic germline BRCA1/BRCA2 variant diagnosed at our hospital between May 1, 2020, and July 31, 2021, comparing current uptake with outcomes achieved for 33 families diagnosed in 2014. Fifteen months after diagnostic testing of the proband, the uptake was 43% (120/277), comparable to the 44% (87/200) registered previously. Among a subgroup of women at 50% risk aged 25-75 years, 71% (47/66) were tested, comparable to an earlier uptake of 69% (59/86). Of the 34 at-risk relatives we contacted directly, 17 (50%) underwent predictive testing. In conclusion, we found no evidence that the new procedure leads to a substantially increased uptake. Future research should be primarily aimed at understanding intrafamilial communication barriers., (© 2023 National Society of Genetic Counselors.)

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. [ABSTRACT FROM AUTHOR]

Introduction: Screening for intracranial aneurysms (IAs) is cost-effective in first-degree relatives of aneurysmal subarachnoid haemorrhage patients, but its psychosocial impact is largely unknown., Patients and Methods: A consecutive series of persons aged 20-70 years visiting the University Medical Centre Utrecht for first screening for familial IA was approached between 2017 and 2020. E-questionnaires were administered at six time points, consisting of the EQ-5D for health-related quality of life (QoL), HADS for emotional functioning, and USER-P for social participation. QoL outcomes were compared with the general population and between participants with a positive and negative screening for IA. Predictors of QoL outcomes were assessed with linear mixed effects models., Results: 105 participants from 75 families were included; in 10 (10%), an IA was found. During the first year after screening, we found no negative effect on QoL, except for a temporary decrease in QoL 6 months after screening in participants with a positive screen (EQ-5D -11.3 [95% CI: -21.7 to -0.8]). Factors associated with worse QoL were psychiatric disease (EQ-5D -10.3 [95% CI: -15.1 to -5.6]), physical complaints affecting mood (EQ-5D -8.1 [95% CI: -11.7 to -4.4]), and a passive coping style (EQ-5D decrease per point increase on the Utrecht Coping List -1.1 [95% CI: -1.5 to -0.6])., Discussion and Conclusion: We did not find a lasting negative effect on QoL during the first year after screening for familial IA. Predictors for a worse QoL were psychiatric disease, physical complaints affecting mood, and a passive coping style. This information can be used in counselling about familial IA screening., (© 2023 The Author(s). Published by S. Karger AG, Basel.)

BackgroundReduced hippocampal size and increased stress sensitivity are associated with psychotic disorder and familial risk for psychosis. However, to what degree the hippocampus is implicated in daily life stress reactivity has not yet been examined. The current study investigated (i) whether familial risk (the contrast between controls, patients and siblings of patients) moderated the relationship between hippocampal volume (HV) and emotional daily stress reactivity and (ii) whether familial risk (the contrast between controls and siblings of patients) moderated the relationship between HV and cortisol daily stress reactivity.MethodT1-weighted magnetic resonance imaging (MRI) scans were acquired from 20 patients with schizophrenia, 37 healthy siblings with familial risk for schizophrenia and 32 controls. Freesurfer 5.0.0 was used to measure HV. The experience sampling method (ESM), a structured momentary assessment technique, was used to assess emotional stress reactivity, that is the effect of momentary stress on momentary negative affect (NA). In addition, in the control and sibling groups, cortisol stress reactivity was assessed using momentary cortisol levels extracted from saliva.ResultsMultilevel linear regression analyses revealed a significant three-way interaction between group, HV and momentary stress in both the model of NA and the model of cortisol. Increased emotional stress reactivity was associated with smaller left HV in patients and larger total HV in controls. In line with the results in patients, siblings with small HV demonstrated increased emotional and cortisol stress reactivity compared to those with large HV.ConclusionsHV may index risk and possibly disease-related mechanisms underlying daily life stress reactivity in psychotic disorder. [ABSTRACT FROM PUBLISHER]

Abstract: Inadequate family communication concerning hereditary lipid disorders by index patients (IPs) may prevent their biological relatives from seeking testing and treatment. This lack of disclosure places the relatives at increased risk for cardiovascular disease. The present study, undertaken in the Netherlands, explored the reasons for family disclosure, and how disclosure was approached. Semi-structured interviews with 20 purposely sampled IPs revealed that they generally alerted their first-degree relatives of the genetic risk because they felt morally obliged to do so or because they were advised to do so by a health professional. However, IPs rarely alerted their more distant relatives due to insufficient risk knowledge or fear of being perceived as interfering in their relative''s affairs. Furthermore, many IPs stated that they would not seek to persuade a relative to undergo testing out of respect for their autonomy. However, the findings did suggest that less direct methods were used for persuasion. An example would be stressing the severity of the condition. Consequently, the self-reported disclosures were incomplete and unbalanced. Typically, IPs provided information regarding the threat of inherited high cholesterol without furnishing information on means of coping with the risk. As IPs want and need professional support to help them disclose this information to their relatives, we suggest additional research about the ethical, practical and economic possibilities for this support. [Copyright &y& Elsevier]

Centronuclear myopathy (CNM) is a genetically heterogeneous congenital myopathy characterized by muscle weakness, atrophy, and variable degrees of cardiorespiratory involvement. The clinical severity is largely explained by genotype (DNM2, MTM1, RYR1, BIN1, TTN, and other rarer genetic backgrounds), specific mutation(s), and age of the patient. The histopathological hallmark of CNM is the presence of internal centralized nuclei on muscle biopsy. Information on the phenotypical spectrum, subtype prevalence, and phenotype-genotype correlations is limited. To characterize CNM more comprehensively, we retrospectively assessed a national cohort of 48 CNM patients (mean age = 32 ± 24 years, range 0-80, 54% males) from the Netherlands clinically, histologically, and genetically. All information was extracted from entries in the patient's medical records, between 2000 and 2020. Frequent clinical features in addition to muscle weakness and hypotonia were fatigue and exercise intolerance in more mildly affected cases. Genetic analysis showed variants in four genes (18 DNM2, 14 MTM1, 9 RYR1, and 7 BIN1), including 16 novel variants. In addition to central nuclei, histologic examination revealed a large variability of myopathic features in the different genotypes. The identification and characterization of these patients contribute to trial readiness., (© 2021 The Authors. Clinical Genetics published by John Wiley & Sons Ltd.)

Background: Familial clustering of melanoma suggests a shared genetic predisposition among family members, but only 10%-40% of familial cases carry a pathogenic variant in a known high-risk melanoma susceptibility gene. We investigated whether a melanoma-specific Polygenic Risk Score (PRS) is associated with melanoma risk in patients with genetically unexplained familial melanoma., Methods: Dutch familial melanoma cases (n=418) were genotyped for 46 SNPs previously identified as independently associated with melanoma risk. The 46-SNP PRS was calculated and standardised to 3423 healthy controls (sPRS) and the association between PRS and melanoma risk was modelled using logistic regression. Within the case series, possible differences were further explored by investigating the PRS in relation to (1) the number of primary melanomas in a patient and (2) the extent of familial clustering of melanoma., Results: The PRS was significantly associated with melanoma risk, with a per-SD OR of 2.12 (95% CI 1.90 to 2.35, p<0.001), corresponding to a 5.70-fold increased risk (95% CI 3.93 to 8.28) when comparing the top 90th to the middle 40-60th PRS percentiles. The mean PRS was significantly higher in cases with multiple primary melanomas than in cases with a single melanoma (sPRS 1.17 vs 0.71, p=0.001). Conversely, cases from high-density melanoma families had a lower (but non-significant) mean PRS than cases from low-density families (sPRS 0.60 vs 0.94, p=0.204)., Conclusion: Our work underlines the significance of a PRS in determining melanoma susceptibility and encourages further exploration of the diagnostic value of a PRS in genetically unexplained melanoma families., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

[Figure: see text].

Both genetic predisposition and low educational attainment (EA) are associated with higher risk of chronic kidney disease. We examined the interaction of EA and genetic risk in kidney function outcomes. We included 3,597 participants from the Prevention of Renal and Vascular End-Stage Disease Cohort Study, a longitudinal study in a community-based sample from Groningen, the Netherlands (median follow-up, 11 years; 1997-2012). Kidney function was approximated by obtaining estimated glomerular filtration rate (eGFR) from serum creatinine and cystatin C. Individual longitudinal linear eGFR trajectories were derived from linear mixed models. Genotype data on 63 single-nucleotide polymorphisms, with known associations with eGFR, were used to calculate an allele-weighted genetic score (WGS). EA was categorized into high, medium, and low. In ordinary least squares analysis, higher WGS and lower EA showed additive effects on reduced baseline eGFR; the interaction term was nonsignificant. In analysis of eGFR decline, the significant interaction term suggested amplification of genetic risk by low EA. Adjustment for known renal risk factors did not affect our results. This study presents the first evidence of gene-environment interaction between EA and a WGS for eGFR decline and provides population-level insights into the mechanisms underlying socioeconomic disparities in chronic kidney disease., (© The Author(s) 2020. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health.)

Background: Pathogenic 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., Methods: Using 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., Results: We identified 172 families in which 649 individuals carried 15 different pathogenic variants. The most prevalent variant was the founder mutation c.225&#95;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%)., Conclusions: Our 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., Competing Interests: Competing interests: DLC is a consultant to Tramedico. MJB received research funding from Boston Scientific, Cook Medical, and Pentax Medical. He is a consultant to Boston Scientific, Cook Medical, Pentax Medical and Mylan. The other authors have no potential competing interests to disclose., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY. Published by BMJ.)

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) <70 years of age. LSS consists of immunohistochemical (IHC) staining for loss of mismatch repair (MMR) protein expression, supplemented with MLH1 methylation analysis if indicated. Test results are evaluated by the treating gynaecologist, who refers eligible patients to a clinical geneticist. We evaluated the implementation of this guideline., Methods: From the nation-wide pathology database we selected all women diagnosed with EC < 70 years of age, treated from 1.6.2016-1.6.2017 in 14 hospitals. We collected data on the results of LSS and follow up of cases with suspected LS., Results: In 183 out of 204 tumours (90%) LSS was performed. In 41 cases (22%) MMR protein expression was lost, in 25 cases due to hypermethylation of the MLH1 promotor. One patient was known with a pathogenic MLH1 variant. The option of genetic counselling was discussed with 12 of the 15 remaining patients, of whom three declined. After counselling by the genetic counsellor nine patients underwent germline testing. In two no pathogenic germline variant was detected, two were diagnosed with a pathogenic PMS2 variant, and five with a pathogenic MSH6 variant, in concordance with the IHC profiles., Conclusion: Coverage of LSS was high (90%), though referral for genetic counselling could be improved. Gynaecologists ought to be aware of the benefits and possible drawbacks of knowing mutational status, and require training in discussing this with their patients., Competing Interests: Declaration of Competing Interest The authors have no conflicts of interest to declare., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

Introduction: We investigated how components of immunity relate to biomarkers of Alzheimer's disease (AD) in plasma and explored the influence of AD genetic risk factors in the population-based Rotterdam Study., Methods: In 7397 persons, we calculated the granulocyte-to-lymphocyte ratio (GLR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII). In 3615 of these persons, plasma amyloid-beta (Aβ)42 and Aβ40 were measured. Next, we constructed an overall genetic risk score (GRS) based on genome-wide significant variants, both including and excluding APOE ε4., Results: All innate immunity phenotypes were related to higher Aβ, most strongly with a doubling in GLR leading to a 1.9% higher Aβ42 (95% confidence interval [95% CI] 0.4 to 3.3%) and 3.2% higher Aβ40 (95% CI 2.0 to 4.3%). Higher AD GRS including APOE ε4 was associated with higher immunity markers., Discussion: Higher levels of immunity markers were associated with higher Aβ in plasma. Participants with a higher genetic predisposition to AD had higher immunity markers, where these effects were mainly driven by APOE ε4., (© 2020 The Authors. Alzheimer's & Dementia published by Wiley Periodicals, Inc. on behalf of Alzheimer's Association.)

Importance: Hidradenitis suppurativa is a chronic, inflammatory skin disease in which genetic factors are considered to play a role, with up to 38% of patients reporting a family history. Variations in the γ-secretase genes are found mainly in familial cases with an autosomal dominant pattern of inheritance. These variations are rare in the general population with hidradenitis suppurativa, even in patients who report a family history of the disease., Objective: To assess the heritability of hidradenitis suppurativa in a nationwide Dutch twin cohort., Design, Setting, and Participants: In this cross-sectional study on self-reported hidradenitis suppurativa conducted from 2011 to 2016, data were collected from twins participating in the surveys of the nationwide Netherlands Twin Register. All complete twin pairs answering the question on hidradenitis suppurativa in the survey were included: 978 female monozygotic twin pairs and 344 male monozygotic twin pairs and 426 female dizygotic twin pairs, 167 male dizygotic twin pairs, and 428 dizygotic twin pairs of the opposite sex. Statistical analysis was performed from July to November 2019., Main Outcomes and Measures: The main outcome is the proportion of susceptibility to hidradenitis suppurativa due to additive genetic factors (narrow-sense heritability), dominant genetic factors, common or shared environmental factors, or unshared or unique environmental factors. The main outcome was evaluated prior to data collection., Results: The prevalence of hidradenitis suppurativa among twin pairs was 1.2% (58 of 4686); the mean (SD) age was 32.7 (15.4) years. The narrow-sense heritability of hidradenitis suppurativa was 77% (95% CI, 54%-90%), with the remainder of the variance due to unshared or unique environmental factors based on an age-adjusted model combining additive genetic factors and unshared or unique environmental factors., Conclusions and Relevance: The high heritability found in this study suggests a stronger than previously assumed genetic basis of hidradenitis suppurativa. Environmental factors were also shown to contribute to the susceptibility to hidradenitis suppurativa, supporting a multifactorial cause of the disease. Moreover, the results of this study strongly support the need for a global genome-wide association study in the general population of patients with hidradenitis suppurativa.

Importance: Both adulthood stressful life events (SLEs) and liability for schizophrenia have been associated with poor mental and physical health in the general population, but their interaction remains to be elucidated to improve population-based health outcomes., Objective: To test whether recent SLEs interact with genetic and environmental liability for schizophrenia in models of mental and physical health., Design, Setting, and Participants: The Netherlands Mental Health Survey and Incidence Study-2 is a population-based prospective cohort study designed to investigate the prevalence, incidence, course, and consequences of mental disorders in the Dutch general population. Participants were enrolled from November 5, 2007, to July 31, 2009, and followed up with 3 assessments during 9 years. Follow-up was completed on June 19, 2018, and data were analyzed from September 1 to November 1, 2019., Exposures: Recent SLEs assessed at each wave and aggregate scores of genetic and environmental liability for schizophrenia: polygenic risk score for schizophrenia (PRS-SCZ) trained using the Psychiatric Genomics Consortium analysis results and exposome score for schizophrenia (ES-SCZ) trained using an independent data set., Main Outcomes and Measures: Independent and interacting associations of SLEs with ES-SCZ and PRS-SCZ on mental and physical health assessed at each wave using regression coefficients., Results: Of the 6646 participants included at baseline, the mean (SD) age was 44.26 (12.54) years, and 3672 (55.25%) were female. The SLEs were associated with poorer physical health (B = -3.22 [95% CI, -3.66 to -2.79]) and mental health (B = -3.68 [95% CI, -4.05 to -3.32]). Genetic and environmental liability for schizophrenia was associated with poorer mental health (ES-SCZ: B = -3.07 [95% CI, -3.35 to -2.79]; PRS-SCZ: B = -0.93 [95% CI, -1.31 to -0.54]). Environmental liability was also associated with poorer physical health (B = -3.19 [95% CI, -3.56 to -2.82]). The interaction model showed that ES-SCZ moderated the association of SLEs with mental (B = -1.08 [95% CI, -1.47 to -0.69]) and physical health (B = -0.64 [95% CI, -1.11 to -0.17]), whereas PRS-SCZ did not. Several sensitivity analyses confirmed these results., Conclusions and Relevance: In this study, schizophrenia liability was associated with broad mental health outcomes at the population level. Consistent with the diathesis-stress model, exposure to SLEs, particularly in individuals with high environmental liability for schizophrenia, was associated with poorer health. These findings underline the importance of modifiable environmental factors during the life span for population-based mental health outcomes.

Advanced colorectal cancer (CRC) consensus molecular subtype 4 (CMS4) or CRC with a low immunoscore is associated with shorter survival times. Non-metastatic CRC with microsatellite instability (MSI) is associated with a lower risk of recurrence. We evaluated outcome (lymph node metastases [LNM] or cancer recurrence) in these tumor subtypes in patients with surgically-removed non-pedunculated T1 CRC by performing a multicenter case-cohort study. We included all patients in 13 hospitals in the Netherlands from 2000-2014 (n = 651). We randomly selected a subgroup of patients (n = 223) and all patients with LNM or recurrence (n = 63), and median follow-up of 44 months. We centrally reviewed tumor-slides, and constructed and immunostained tissue microarrays determining MSI, CMS (MSI/CMS1, CMS2/3, or CMS4), and immunoscore (I-low/I-high). We used weighted Cox proportional hazard models to evaluate the association of MSI, CMS, and immunoscore with LNM or recurrence, adjusting for conventional histologic risk factors. In the randomly selected subgroup of patients, 7.1% of tumors were MSI/CMS1, 91.0% CMS2/3, 1.8% CMS4, and 25% I-low. In the case-cohort, patients with CMS4 tumors had an increased risk for LNM or recurrence compared with patients with tumors of other CMSs (adjusted hazard ratio [HR], 3.97; 95% CI, 1.12-14.06; P = 0.03). Albeit not significant, tumors with MSI had a lower risk for LNM or recurrence than other tumor subtypes (adjusted HR, 0.52; 95% CI, 0.12-2.30; P = 0.39), whereas tumors with a low immunoscore had an increased risk for LNM or recurrence (adjusted HR, 1.30; 95% CI, 0.68-2.48; P = 0.43). In conclusion, in a case-cohort study of patients with non-pedunculated T1 CRC, MSI, and immunoscore were not significantly associated with adverse outcome after surgery. CMS4 substantially increased the risk of adverse outcome. However, CMS4 is rare in T1 CRCs, limiting its value for determining the risk in patients.

Pulmonary arterial hypertension (PAH) is a severe, life-threatening disease, and in some cases is caused by genetic defects. This study sought to assess the diagnostic yield of genetic testing in a Dutch cohort of 126 PAH patients. Historically, genetic testing in the Netherlands consisted of the analysis of BMPR2 and SMAD9. These genes were analyzed in 70 of the 126 patients. A (likely) pathogenic (LP/P) variant was detected in 22 (31%) of them. After the identification of additional PAH associated genes, a next generation sequencing (NGS) panel consisting of 19 genes was developed in 2018. Additional genetic testing was offered to the 48 BMPR2 and SMAD9 negative patients, out of which 28 opted for NGS analysis. In addition, this gene panel was analyzed in 56 newly identified idiopathic (IPAH) or pulmonary veno occlusive disease (PVOD) patients. In these 84 patients, NGS panel testing revealed LP/P variants in BMPR2 ( N = 4), GDF2 ( N = 2), EIF2AK4 ( N = 1), and TBX4 ( N = 3). Furthermore, 134 relatives of 32 probands with a LP/P variant were tested, yielding 41 carriers. NGS panel screening offered to IPAH/PVOD patients led to the identification of LP/P variants in GDF2, EIF2AK4, and TBX4 in six additional patients. The identification of LP/P variants in patients allows for screening of at-risk relatives, enabling the early identification of PAH.

Metachromatic leukodystrophy (MLD) is an autosomal recessively inherited sulfatide storage disease caused by deficient activity of the lysosomal enzyme arylsulfatase A (ASA). Genetic analysis of the ARSA gene is important in MLD diagnosis and screening of family members. In addition, more information on genotype prevalence will help interpreting MLD population differences between countries. In this study, we identified 31 different ARSA variants in the patient cohort (n = 67) of the Dutch expertise center for MLD. The most frequently found variant, c.1283C > T, p.(Pro428Leu), was present in 43 (64%) patients and resulted in a high prevalence of the juvenile MLD type (58%) in The Netherlands. Furthermore, we observed in five out of six patients with a non-Caucasian ethnic background previously unreported pathogenic ARSA variants. In total, we report ten novel variants including four missense, two nonsense, and two frameshift variants and one in-frame indel, which were all predicted to be disease causing in silico. In addition, one silent variant was found, c.1200C > T, that most likely resulted in erroneous exonic splicing, including partial skipping of exon 7. The c.1200C > T variant was inherited in cis with the pseudodeficiency allele c.1055A > G, p.(Asn352Ser) + ∗96A > G. With this study we provide a genetic base of the unique MLD phenotype distribution in The Netherlands. In addition, our study demonstrated the importance of genetic analysis in MLD diagnosis and the increased likelihood of unreported, pathogenic ARSA variants in patients with non-Caucasian ethnic backgrounds.

The uptake of predictive DNA testing in families with a hereditary disease is <50%. Current practice often relies on the proband to inform relatives about the possibility of predictive DNA testing, but not all relatives are informed adequately. To enable informed decision-making concerning predictive DNA testing, the approach used to inform at-risk relatives needs to be optimized. This study investigated the preferences of patients, relatives, and the general population from the Netherlands on how to inform relatives at risk of autosomal dominant diseases. Online surveys were sent to people with autosomal dominant neuro-, onco-, or cardiogenetic diseases and their relatives via patient organizations (n = 379), and to members of the general population via a commercial panel (n = 1,000). Attitudes of the patient and population samples generally corresponded. A majority believed that initially only first-degree relatives should be informed, following the principles of a cascade screening approach. Most participants also thought that probands and healthcare professionals (HCPs) should be involved in informing relatives, and a large proportion believed that HCPs should contact relatives directly in cases where patients are unwilling to inform, both for untreatable and treatable conditions. Participants from the patient sample were of the opinion that HCPs should actively offer support. Our findings show that both patients and HCPs should be involved in informing at-risk relatives of autosomal dominant diseases and suggest that relatives' 'right to know' was considered a dominant issue by the majority of participants. Further research is needed on how to increase proactive support in informing of at-risk relatives., (© 2019 The Authors. Journal of Genetic Counseling published by Wiley Periodicals, Inc. on behalf of National Society of Genetic Counselors.)

Inference of causality between gene expression and complex traits using Mendelian randomization (MR) is confounded by pleiotropy and linkage disequilibrium (LD) of gene-expression quantitative trait loci (eQTL). Here, we propose an MR method, MR-link, that accounts for unobserved pleiotropy and LD by leveraging information from individual-level data, even when only one eQTL variant is present. In simulations, MR-link shows false-positive rates close to expectation (median 0.05) and high power (up to 0.89), outperforming all other tested MR methods and coloc. Application of MR-link to low-density lipoprotein cholesterol (LDL-C) measurements in 12,449 individuals with expression and protein QTL summary statistics from blood and liver identifies 25 genes causally linked to LDL-C. These include the known SORT1 and ApoE genes as well as PVRL2, located in the APOE locus, for which a causal role in liver was not known. Our results showcase the strength of MR-link for transcriptome-wide causal inferences.

Objective: To describe the prevalence of pulmonary arterial hypertension (PAH)-associated gene mutations, and other genetic characteristics in a national cohort of children with PAH from the Dutch National registry and to explore genotype-phenotype associations and outcomes., Study Design: Children (n = 70) diagnosed with idiopathic PAH, heritable PAH, PAH associated with congenital heart disease with coincidental shunt (PAH-congenital heart disease group 3), PAH after closure of a cardiac shunt (PAH-congenital heart disease group 4), or PAH associated with other noncardiac conditions were enrolled. Targeted next-generation sequencing was performed on PAH-associated genes (BMPR2, ACVRL1, EIF2AK4, CAV1, ENG, KCNK3, SMAD9, and TBX4). Also, children were tested for specific genetic disorders in case of clinical suspicion. Additionally, children were tested for copy number variations., Results: Nineteen children (27%) had a PAH-associated gene mutation/variant: BMPR2 n = 7, TBX4 n = 8, ACVRL1 n = 1, KCNK3 n = 1, and EIF2AK4 n = 2. Twelve children (17%) had a genetic disorder with an established association with PAH (including trisomy 21 and cobalamin C deficiency). In another 16 children (23%), genetic disorders without an established association with PAH were identified (including Noonan syndrome, Beals syndrome, and various copy number variations). Survival rates differed between groups and was most favorable in TBX4 variant carriers., Conclusions: Children with PAH show a high prevalence of genetic disorders, not restricted to established PAH-associated genes. Genetic architecture could play a role in risk-stratified care management in pediatric PAH., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background and Objectives: A genetic cause can be identified for an increasing number of pediatric and adult-onset kidney diseases. Preimplantation genetic testing (formerly known as preimplantation genetic diagnostics) is a reproductive technology that helps prospective parents to prevent passing on (a) disease-causing mutation(s) to their offspring. Here, we provide a clinical overview of 25 years of preimplantation genetic testing for monogenic kidney disease in The Netherlands., Design, Setting, Participants, & Measurements: This is a retrospective cohort study of couples counseled on preimplantation genetic testing for monogenic kidney disease in the national preimplantation genetic testing expert center (Maastricht University Medical Center+) from January 1995 to June 2019. Statistical analysis was performed through chi-squared tests., Results: In total, 98 couples were counseled regarding preimplantation genetic testing, of whom 53% opted for preimplantation genetic testing. The most frequent indications for referral were autosomal dominant polycystic kidney disease (38%), Alport syndrome (26%), and autosomal recessive polycystic kidney disease (9%). Of couples with at least one preimplantation genetic testing cycle with oocyte retrieval, 65% experienced one or more live births of an unaffected child. Of couples counseled, 38% declined preimplantation genetic testing for various personal and technical reasons., Conclusions: Referrals, including for adult-onset disease, have increased steadily over the past decade. Though some couples decline preimplantation genetic testing, in the couples who proceed with at least one preimplantation genetic testing cycle, almost two thirds experienced at least one live birth rate., (Copyright © 2020 by the American Society of Nephrology.)

Background: Germline mutations in the gene encoding TERT cause haploinsufficiency with subsequent telomere shortening. TERT mutations are associated with short telomere syndromes, such as pulmonary fibrosis (PF), which is often the first manifestation of a short telomere syndrome. Telomere length is heritable, and progeny of telomerase mutation carriers are known to have shorter telomeres. In families with TERT mutations, genetic anticipation, the earlier onset of symptoms with successive generation, is described. Little is known on the number of generations that may pass before disease occurs in families with a TERT mutation., Research Question: The objective of this study was to determine classification and origin of the new TERT c.2005T mutation from population genetics and genealogic data and disease history of affected families., Study Design and Methods: The TERT gene of 240 patients with familial PF was screened for mutations. Additionally, 1,015 patients with PF, 1,237 patients with an interstitial lung disease (ILD) without PF, and 529 healthy control subjects were genotyped for the TERT c.2005C>T mutation. Genealogic research was performed on all patients who carried the TERT c.2005T mutation., Results: We detected the TERT c.2005T (p.Arg669Trp) mutation in 13 out of 1,255 patients with PF vs none of the patients with ILD without PF and the healthy control subjects. Genealogic research connected four of the TERT c.2005T mutation carriers to a common ancestor who lived seven generations back, spanning a period of 300 years., Interpretation: The TERT c.2005T mutation is a pathogenic mutation and associates with PF. This study learns that a latency period of > 300 years may pass before the cumulative effect of telomere shortening eventually leads to PF. This finding underlines the complexity of the clinical interpretation of TERT mutations because, not the presence of the mutation, but the result of genetic anticipation, is associated with disease. Therefore, multidisciplinary discussion between pulmonary physicians, clinical geneticists, and genetic laboratory experts is recommended., (Copyright © 2020 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)

Objectives: The objectives of this study were to investigate the effect of genetic and social factors on depressive symptoms and depression over time and to test whether social factors moderate the relationship between depressive symptoms and its underlying genetics in later life., Methods: The study included 2,279 participants with a mean follow-up of 15 years from the Longitudinal Aging Study Amsterdam with genotyping data. The personal genetic loading for depression was estimated for each participant by calculating a polygenic risk scores (PRS-D), based on 23,032 single nucleotide polymorphisms associated with major depression in a large genome-wide association study. Partner status, network size, received and given emotional support were assessed via questionnaires and depressive symptoms were assessed using the CES-D Scale. A CES-D Scale of 16 and higher was considered as clinically relevant depression., Results: Higher PRS-D was associated with more depressive symptoms whereas having a partner and having a larger network size were independently associated with less depressive symptoms. After extra adjustment for education, cognitive function and functional limitations, giving more emotional support was also associated with less depressive symptoms. No evidence for gene-environment interaction between PRS-D and social factors was found. Similar results were found for clinically relevant depression., Conclusion: Genetic and social factors are independently associated with depressive symptoms over time in older adults. Strategies that boost social functioning should be encouraged in the general population of older adults regardless of the genetic liability for depression., (Copyright © 2020 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.)

Background: For most disease-related traits the magnitude of the contribution of genetic factors in adolescents remains unclear., Methods: Twenty continuous traits related to anthropometry, cardiovascular and renal function, metabolism, and inflammation were selected from the ongoing prospective Tracking Adolescents' Individual Lives Survey cohort in the Netherlands with measurements of up to 5 waves from age 11 to 22 years (n=1354, 47.6% males) and all traits available at the third wave (mean age [SD]=16.22 [0.66]). For each trait, unweighted and weighted genetic risk scores (GRSs) were generated based on significantly associated single nucleotide polymorphisms identified from literature. The variance explained by the GRSs in adolescents were estimated by linear regression after adjustment for covariates., Results: Except for ALT (alanine transaminase), all GRSs were significantly associated with their traits. The trait variance explained by the GRSs was highest for lipoprotein[a] (39.59%) and varied between 0.09% (ALT) and 18.49% (LDL [low-density lipoprotein]) for the other traits. For most traits, the variances explained in adolescents were comparable with or slightly smaller than those in adults. Significant increases of trait levels (except ALT) and increased risks for overweight/obesity (odds ratio, 6.41 [95% CI, 2.95-15.56]) and hypertension (odds ratio, 2.86 [95% CI, 1.39-6.17]) were found in individuals in the top GRS decile compared with those at the bottom decile., Conclusions: Variances explained by adult-based GRSs for disease-related traits in adolescents, although still relatively modest, were comparable with or slightly smaller than in adults offering promise for improved risk prediction at early ages.

The origin of primary mucinous ovarian tumors is unknown. We explore the hypothesis that they originate from either Brenner tumors or teratomas and examine differences between the tumors that arise in these settings. A total of 104 Brenner tumor-associated mucinous tumors and 58 teratoma-associated mucinous tumors were analyzed. Immunohistochemistry for 21 antigens and fluorescence in situ hybridization for ERBB2 and MYC were performed. Genome-wide copy number analysis and mutation analysis for 56 cancer-related genes was carried out on a subset of mucinous ovarian tumors and their complementary Brenner tumor or teratoma. Patients with teratoma-associated mucinous tumors were significantly younger than patients with Brenner tumor-associated mucinous tumors (43 vs. 61 years). During progression from cystadenoma to atypical proliferative mucinous (borderline) tumor to carcinoma expression of typical gastrointestinal markers was increased in both Brenner tumor-associated and teratoma-associated mucinous tumors. Brenner tumor-associated mucinous tumors showed more frequently calcifications and Walthard cell nests, rarely expressed SATB2 and showed more often co-deletion of CDKN2A and MTAP. Teratoma-associated mucinous tumors were characterized by mucinous stromal dissection, SATB2 expression and RNF43 mutations. Other frequent mutations in both Brenner tumor-associated and teratoma-associated mucinous tumors were TP53 and KRAS mutations. Based on identical mutations or copy number profiles clonal relationships were indicated in two mucinous tumors and their associated Brenner tumor. Teratomas and Brenner tumors give rise to different subtypes of mucinous ovarian tumors. Subsequent progression pathways are comparable since both Brenner tumor-associated and teratoma-associated mucinous tumors develop a gastrointestinal immunophenotype during progression and show early mutations in KRAS and TP53. Teratoma-associated mucinous tumors may more closely resemble true gastrointestinal tumors, indicated by their expression of SATB2 and the presence of RNF43 mutations.

Objective: To investigate to what extent low-frequency genetic variants (with minor allele frequencies <5%) affect the risk of intracranial aneurysms (IAs)., Methods: One thousand fifty-six patients with IA and 2,097 population-based controls from the Netherlands were genotyped with the Illumina HumanExome BeadChip. After quality control (QC) of samples and single nucleotide variants (SNVs), we conducted a single variant analysis using the Fisher exact test. We also performed the variable threshold (VT) test and the sequence kernel association test (SKAT) at different minor allele count (MAC) thresholds of >5 and >0 to test the hypothesis that multiple variants within the same gene are associated with IA risk. Significant results were tested in a replication cohort of 425 patients with IA and 311 controls, and results of the 2 cohorts were combined in a meta-analysis., Results: After QC, 995 patients with IA and 2,080 controls remained for further analysis. The single variant analysis comprising 46,534 SNVs did not identify significant loci at the genome-wide level. The gene-based tests showed a statistically significant association for fibulin 2 ( FBLN2 ) (best p = 1 × 10 -6 for the VT test, MAC >5). Associations were not statistically significant in the independent but smaller replication cohort ( p > 0.57) but became slightly stronger in a meta-analysis of the 2 cohorts (best p = 4.8 × 10 -7 for the SKAT, MAC ≥1)., Conclusion: Gene-based tests indicated an association for FBLN2 , a gene encoding an extracellular matrix protein implicated in vascular wall remodeling, but independent validation in larger cohorts is warranted. We did not identify any significant associations for single low-frequency genetic variants., (© 2019 American Academy of Neurology.)

Objective: Sudden cardiac death (SCD) in families with premature atherosclerosis (PAS) is generally attributed to lethal arrhythmias during myocardial infarction. Yet, such arrhythmias may also arise from non-ischaemic inherited susceptibility. We aimed to test the hypothesis that Brugada syndrome is prevalent among families with PAS in which SCD occurred., Methods: We investigated all patients who underwent Ajmaline testing to screen them for Brugada syndrome because of unexplained familial SCD in the Amsterdam University Medical Centers between 2004 and 2017. We divided the cohort into two groups based on a positive family history for PAS. All individuals with a positive Ajmaline test were screened for SCN5A-mutation., Results: In families with SCD and PAS, the prevalence of positive Ajmaline test was similar to families with SCD alone (22% vs 19%). The number of SCD cases in families with SCD and PAS was higher (2.34 vs 1.63, p<0.001) and SCD occurred at older age in families with SCD and PAS (42 years vs 36 years, p<0.001), while the prevalence of SCN5A mutations was lower (3% vs 18%, p<0.05)., Conclusions: Brugada syndrome has a similar prevalence in families with SCD and PAS as in families with SCD alone, although SCD in families with SCD and PAS occurs in more family members and at older age, while SCN5A mutations in these families are rare. This suggests that the SCD occurring in families with PAS could be related to an underlying genetic predisposition of arrhythmias, with a different genetic origin. It could be considered to screen families with SCD and PAS for Brugada syndrome., Competing Interests: Competing interests: All authors take responsibility for all aspects of the reliability and freedom from bias of the data presented and their discussed interpretation., (© Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Initial studies have suggested the familial clustering of mitral valve prolapse, but most of them were either community based among unselected individuals or applied non-specific diagnostic criteria. Therefore little is known about the familial distribution of mitral regurgitation in a referral-type population with a more severe mitral valve prolapse phenotype. The objective of this study was to evaluate the presence of familial mitral regurgitation in patients undergoing surgery for mitral valve prolapse, differentiating patients with Barlow's disease, Barlow forme fruste and fibro-elastic deficiency., Methods: A total of 385 patients (62 ± 12 years, 63% men) who underwent surgery for mitral valve prolapse were contacted to assess cardiac family history systematically. Only the documented presence of mitral regurgitation was considered to define 'familial mitral regurgitation'. In the probands, the aetiology of mitral valve prolapse was defined by surgical observations., Results: A total of 107 (28%) probands were classified as having Barlow's disease, 85 (22%) as Barlow forme fruste and 193 (50%) patients as fibro-elastic deficiency. In total, 51 patients (13%) reported a clear family history for mitral regurgitation; these patients were significantly younger, more often diagnosed with Barlow's disease and also reported more sudden death in their family as compared with 'sporadic mitral regurgitation'. In particular, 'familial mitral regurgitation' was reported in 28 patients with Barlow's disease (26%), 15 patients (8%) with fibro-elastic deficiency and eight (9%) with Barlow forme fruste ( P  < 0.001)., Conclusions: In a large cohort of patients operated for mitral valve prolapse, the self-reported prevalence of familial mitral regurgitation was 26% in patients with Barlow's disease and still 8% in patients with fibro-elastic deficiency, highlighting the importance of familial anamnesis and echocardiographic screening in all mitral valve prolapse patients.

Next generation sequencing has enabled fast and relatively inexpensive expanded carrier screening (ECS) that can inform couples' reproductive decisions before conception and during pregnancy. We previously showed that a couple-based approach to ECS for autosomal recessive (AR) conditions was acceptable and feasible for both health care professionals and the non-pregnant target population in the Netherlands. This paper describes the acceptance of this free test-offer of preconception ECS for 50 severe conditions, the characteristics of test-offer acceptors and decliners, their views on couple-based ECS and reasons for accepting or declining the test-offer. We used a survey that included self-rated health, intention to accept the test-offer, barriers to test-participation and arguments for and against test-participation. Fifteen percent of the expected target population-couples potentially planning a pregnancy-attended pre-test counselling and 90% of these couples proceeded with testing. Test-offer acceptors and decliners differed in their reproductive characteristics (e.g. how soon they wanted to conceive), educational level and stated barriers to test-participation. Sparing a child a life with a severe genetic condition was the most important reason to accept ECS. The most important reason for declining was that the test-result would not affect participants' reproductive decisions. Our results demonstrate that previously uninformed couples of reproductive age, albeit a selective part, were interested in and chose to have couple-based ECS. Alleviating practical barriers, which prevented some interested couples from participating, is recommended before nationwide implementation.

Ataxia telangiectasia (A-T) is a severe neurodegenerative disorder with variable immunodeficiency. Together with the Dutch A-T community, we investigated the opinion of A-T parents on an early A-T diagnosis in the asymptomatic phase of the disease. During an annual national meeting for A-T patients and families, the topic of an early A-T diagnosis was discussed in relation to the recent introduction of neonatal screening for severe combined immunodeficiency (SCID) in the Netherlands. Based on the discussion, individual arguments were identified and processed into a questionnaire, which was sent out to 64 A-T parents (32 families). Arguments included were insecurity to diagnosis, possible medical advantages, appropriate genetic counseling and family planning, loss of "golden" year(s), and early cancer screening for parents. The response rate was 55% (n = 35 parents). Twenty-six (74%) parents felt that the advantages of an early diagnosis outweighed the disadvantages, five parents thought that the disadvantages would outweigh the advantages (14%), and four parents did not indicate a preference.Conclusion: The majority of parents of a child with A-T would have preferred an early diagnosis during the asymptomatic phase of the disease, because the uncertainty during the diagnostic process had had a major impact on their lives. In addition, the knowledge of being carriers of an ATM gene mutation influenced decisions about family planning. Parents who opposed against an early diagnosis emphasized the joy of having a seemingly healthy child until diagnosis.What is Known:• Ataxia telangiectasia (A-T) is a devastating DNA repair disorder with a huge impact on quality of life of patients and their parents.• Patients with A-T may incidentally be identified at birth as the consequence of neonatal screening for severe combined immunodeficiency (SCID).What is New:• The majority of Dutch parents of A-T patients (74%) would have preferred an early diagnosis of their child in the asymptomatic phase of the disease.• Major arguments for an early A-T diagnosis were (1) the experienced insecurity in diagnostic trajectories and its impact on families and (2) the knowledge of being ATM mutation carriers when deciding about family planning. An argument against an early diagnosis is losing the joy of having a seemingly healthy child until diagnosis.

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 < 0.02), and clinical geneticists scored lower on SDM compared with other types of counselors (p < 0.03). Our findings that counselors mainly communicate scientific uncertainties and use space-reducing responses imply that the way counselors address counselees' personal uncertainties and concerns during initial cancer genetic counseling is suboptimal.

This study presents a broad overview of health issues and psychomotor development of 100 children with Angelman syndrome (AS), seen at the ENCORE Expertise Center for AS in Rotterdam, the Netherlands. We aimed to further delineate the phenotype of AS, to evaluate the association of the phenotype with genotype and other determinants such as epilepsy and to get insight in possible targets for intervention. We confirmed the presence of a more severe phenotype in the 15q11.2-q13 deletion subtype. Novel findings were an association of (early onset of) epilepsy with a negative effect on development, a high occurrence of nonconvulsive status epilepticus, a high rate of crouch gait in the older children with risk of deterioration of mobility, a relatively low occurrence of microcephaly, a higher mean weight for height in all genetic subtypes with a significant higher mean in the nondeletion children, and a high occurrence of hyperphagia across all genetic subtypes. Natural history data are needed to design future trials. With this large clinical cohort with structured prospective and multidisciplinary follow-up, we provide unbiased data on AS to support further intervention studies to optimize outcome and quality of life of children with AS and their family., (© 2019 The Authors. American Journal of Medical Genetics Part A published by Wiley Periodicals, Inc.)

Background: Childhood eczema is variable in onset and persistence., Objectives: To identify eczema phenotypes during childhood, and their associations with early-life environmental and genetic factors., Methods: In this study of 5297 children from a multiethnic population-based prospective cohort study, phenotypes based on parent-reported physician-diagnosed eczema from age 6 months to 10 years were identified using latent class growth analysis. Information on environmental factors was obtained using postal questionnaires. Four filaggrin mutations were genotyped and a risk score was calculated based on 30 genetic variants. Weighted adjusted multinomial models were used for association analyses., Results: We identified the following five eczema phenotypes: never (76%), early transient (8%), mid-transient (6%) and late transient (8%) and persistent eczema (2%). Early transient and persistent eczema were most common in first-born children, those with a parental history of eczema, allergy or asthma and those with persistent wheezing [range of odds ratio (OR): 1.37, 95% confidence interval (CI) 1.07-1.74 and OR 3.38, 95%CI 1.95-5.85]. Early transient eczema was most common in male children only (OR 1·49, 95% CI 1·18-1·89). Children with late transient or persistent eczema were more often of Asian ethnicity (OR 2·04, 95% CI 1·14-3·65 and OR 3·08, 95% CI 1·34-7·10, respectively). Children with early, late transient and persistent eczema more often had a filaggrin mutation or additional risk alleles (range OR: 1.07, 95%CI 1.02-1.12 and OR 2.21, 95%CI 1.39-3.50). Eczema phenotypes were not associated with maternal education, breastfeeding, day care attendance and pet exposure., Conclusions: Five eczema phenotypes were identified in a multiethnic paediatric population with limited differences in risk profiles, except for sex and ethnicity. What's already known about this topic? Two previous studies in longitudinal birth cohorts identified four and six different eczema phenotypes, predominantly in children of European ethnicity. What does this study add? Five eczema phenotypes were identified in a multiethnic paediatric population using latent class growth analysis. Children with early transient and persistent eczema were most often first-born children and had persistent wheezing, filaggrin mutation or additional risk alleles. Previously known eczema risk factors had limited differentiating capabilities for eczema phenotypes, except for the association of early transient eczema with male children, and late transient and persistent eczema with Asian ethnicity., (© 2019 The Authors. British Journal of Dermatology published by John Wiley & Sons Ltd on behalf of British Association of Dermatologists.)

A proportion of patients diagnosed with melanoma has a positive family history. Despite increasing knowledge on the genes responsible for familial clustering, the genetic basis in the majority of the families with an inherited predisposition to melanoma remains to be clarified. To identify novel melanoma-susceptibility genes, we applied whole-exome sequencing on DNA from two members of a family with four melanoma cases, not explained by established high penetrance melanoma-susceptibility genes. Whole-exome sequencing identified 10 rare, co-segregating, predicted deleterious missense gene variants. Subsequent co-segregation analysis revealed that only variants in the DOT1L (R409H) and the SLCO4C1 (P597A) genes were present in the other two affected members of this family. DOT1L is a methyltransferase that methylates histone H3 lysine 79 (H3K79). It is involved in maintenance of genomic stability, since mutations in the DOT1L gene have been previously reported to compromise the removal of ultraviolet photoproducts in ultraviolet-irradiated melanocytes, thereby enhancing malignant transformation. We hypothesized that the presence of DOT1L R409H variant might be associated with an increased risk of melanoma, since we found co-segregation of the DOT1L mutation in all four melanoma-affected family members. However, this missense variant did neither lead to detectable loss-of-heterozygosity nor reduction of histone methyltransferase activity in melanoma samples from mutation carriers nor altered ultraviolet-survival of mouse embryonic stem cells containing an engineered homozygous DOT1L R409H mutation. Although functional analysis of this rare co-segregating variant did not reveal compromised histone methyltransferase activity and ultraviolet exposure sensitivity, the role of DOT1L as melanoma susceptibility gene deserves further study.

Genetic variation in the insulin-like growth factor (IGF) pathway may further increase the risk of colorectal cancer (CRC) associated with type 2 diabetes mellitus (T2DM). Joint effects of T2DM and genetic variation in the IGF pathway on CRC risk can increase mechanistic insights. Participants from the Netherlands Cohort Study (n = 120, 852) completed a baseline questionnaire in 1986 when 55-69 years old (case-cohort, n subcohort  = 5,000, n cases  = 3,441 after 16.3 years follow-up). Self-reported DM at baseline with onset at ≥30 years was classified as T2DM. Eighteen single nucleotide polymorphisms (SNPs) from the IGF pathway were aggregated in a genetic risk score (GRS). Cox proportional hazard ratios (HRs) for CRC were estimated according to combinations of T2DM status with GRS tertiles and categories of an IGF1 19-CA repeat polymorphism. Baseline T2DM prevalence was 3.1% in subcohort members and 3.8% in CRC cases. Comparison of combined categories with non-T2DM individuals in the lowest GRS tertile as reference showed that those in the highest GRS tertiles with and without T2DM had significantly increased CRC risks, particularly those with T2DM (HR = 2.28, 95% CI: 1.11, 4.66). As compared to IGF1 19-CA wild-type carriers without T2DM, carrying two IGF1 19-CA variant repeat alleles were associated with a significantly decreased CRC risk in those without T2DM (HR = 0.76, 95% CI: 0.63-0.91). This association was absent when T2DM was present. Our study of joint effects indicated that the presence of unfavorable alleles in the IGF pathway may further increase the risk of CRC associated with T2DM., (© 2019 The Authors. International Journal of Cancer published by John Wiley & Sons Ltd on behalf of UICC.)

Carriers of pathogenic variants in CDKN2A have a 70% life-time risk of developing melanoma and 15-20% risk of developing pancreatic cancer (PC). In the Netherlands, a 19-bp deletion in exon 2 of CDKN2A (p16-Leiden mutation) accounts for most hereditary melanoma cases. Clinical experience suggests variability in occurrence of melanoma and PC in p16-Leiden families. Thereby, the risk of developing cancer could be modified by both environmental and genetic contributors, suggesting that identification of genetic modifiers could improve patients' surveillance. In a recent genome-wide association study (GWAS), rs36115365-C was found to significantly modify risk of PC and melanoma in the European population. This SNP is located on chr5p15.33 and has allele-specific regulatory activities on TERT expression. Herein, we investigated the modifying capacities of rs36115365-C on PC and melanoma in a cohort of 283 p16-Leiden carriers including 29 diagnosed with PC, 171 diagnosed with melanoma, 21 diagnosed with both PC and melanoma and 62 with neither PC nor melanoma. In contrast to previously reported findings, we did not find a significant association of PC risk with risk variant presence as determined by Generalized Estimating Equations (GEE) modelling. Interestingly, carrier-ship of the risk variant had a significant protective effect for melanoma (OR - 0.703 [95% CI - 1.201 to - 0.205], p = 0.006); however, the observed association was no longer significant after exclusion of probands to assess possible influence of ascertainment. Collectively, genetic modifiers for the prediction of PC and melanoma risk in p16-Leiden carriers remain to be determined.

Germline mutations of BRCA1 and BRCA2 predispose individuals to a high risk of breast and ovarian cancer, and elevated risk of other cancers, including those of the pancreas and prostate. BRCA2 mutation carriers may have increased risk of uveal melanoma (UM) and cutaneous melanoma (CM), but associations with these cancers in BRCA1 mutation carriers have been mixed. Here, we further assessed whether UM and CM are associated with BRCA1 or BRCA2 by assessing the presence, segregation and reported/predicted pathogenicity of rare germline mutations (variant allele frequency < 0.01) in families with multiple members affected by these cancers. Whole-genome or exome sequencing was performed on 160 CM and/or UM families from Australia, the Netherlands, Denmark and Sweden. Between one and five cases were sequenced from each family, totalling 307 individuals. Sanger sequencing was performed to validate BRCA1 and BRCA2 germline variants and to assess carrier status in other available family members. A nonsense and a frameshift mutation were identified in BRCA1, both resulting in premature truncation of the protein (the first at p.Q516 and the second at codon 91, after the introduction of seven amino acids due to a frameshift deletion). These variants co-segregated with CM in individuals who consented for testing and were present in individuals with pancreatic, prostate and breast cancer in the respective families. In addition, 33 rare missense mutations (variant allele frequency ranging from 0.00782 to 0.000001 in the aggregated ExAC data) were identified in 34 families. Examining the previously reported evidence of functional consequence of these variants revealed all had been classified as either benign or of unknown consequence. Seeking further evidence of an association between BRCA1 variants and melanoma, we examined two whole-genome/exome sequenced collections of sporadic CM patients (total N = 763). We identified one individual with a deleterious BRCA1 variant, however, this allele was lost (with the wild-type allele remaining) in the corresponding CM, indicating that defective BRCA1 was not a driver of tumorigenesis in this instance. Although this is the first time that deleterious BRCA1 mutations have been described in high-density CM families, we conclude that there is an insufficient burden of evidence to state that the increased familial CM or UM susceptibility is because of these variants. In addition, in conjunction with other studies, we conclude that the previously described association between BRCA2 mutations and UM susceptibility represents a rare source of increased risk.