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Background: Vascular Ehlers-Danlos syndrome (vEDS) is a rare connective tissue disorder with a high risk for arterial, bowel, and uterine rupture, caused by heterozygous pathogenic variants in COL3A1 . The aim of this cohort study is to provide further insights into the natural history of vEDS and describe genotype-phenotype correlations in a Dutch multicenter cohort to optimize patient care and increase awareness of the disease., Methods: Individuals with vEDS throughout the Netherlands were included. The phenotype was charted by retrospective analysis of molecular and clinical data, combined with a one-time physical examination., Results: A total of 142 individuals (50% female) participated the study, including 46 index patients (32%). The overall median age at genetic diagnosis was 41.0 years. More than half of the index patients (54.3%) and relatives (53.1%) had a physical appearance highly suggestive of vEDS. In these individuals, major events were not more frequent ( P =0.90), but occurred at a younger age ( P =0.01). A major event occurred more often and at a younger age in men compared with women ( P <0.001 and P =0.004, respectively). Aortic aneurysms ( P =0.003) and pneumothoraces ( P =0.029) were more frequent in men. Aortic dissection was more frequent in individuals with a COL3A1 variant in the first quarter of the collagen helical domain ( P =0.03)., Conclusions: Male sex, type and location of the COL3A1 variant, and physical appearance highly suggestive of vEDS are risk factors for the occurrence and early age of onset of major events. This national multicenter cohort study of Dutch individuals with vEDS provides a valuable basis for improving guidelines for the diagnosing, follow-up, and treatment of individuals with vEDS., Competing Interests: Disclosures None.

Background: The Worm Study, ascertained from a multigeneration pedigree segregating a single amino acid deletion in SCN5A (c.4850&#95;4852delTCT, p.(Phe1617del), rs749697698), is characterized by substantial phenotypic heterogeneity and overlap of sudden cardiac death, long-QT syndrome, cardiac conduction disease, Brugada syndrome, and isorhythmic atrioventricular dissociation. Linkage analysis for a synthetic trait derived from these phenotypes identified a single peak (logarithm of the odds [LOD] = 4.52) at the SCN5A/SCN10A/SCN11A locus on chromosome 3., Objective: This study explored the role of additional genetic variation in the chromosome 3 locus as a source of phenotypic heterogeneity in the Worm Study population., Methods: Genotypes underlying the linkage peak (n = 70) were characterized using microarrays. Haplotypes were determined using family-aware phasing and a population-specific reference panel. Variants with minor allele frequencies >0.10 were tested for association with cardiac conduction disease and isorhythmic dissociation using LAMP and logistic regression., Results: Only 1 haplotype carried the p.Phe1617del/rs749697698 deletion, suggesting relatively recent development (∼18 generations); this haplotype contained 5 other missense variants spanning SCN5A/SCN10A/SCN11A. Noncarrier haplotypes (n = 74) ranged in frequency from 0.5% to 5%. Although no variants were associated with cardiac conduction disease, a homozygous missense variant in SCN10A was associated with isorhythmic dissociation after correction for multiple comparisons (odds ratio 11.23; 95% confidence interval 2.76-23.39; P = 1.2 × 10 -4 ). This variant (rs12632942) was previously associated with PR interval., Conclusion: Our data suggest that other variants, alongside a pathogenic mutation, are associated with phenotypic heterogeneity. Single-mutation screening may be insufficient to predict electrical heart disease in patients and family members. In the Worm Study population, segregating a pathogenic SCN5A mutation, compound variation in the SCN5A/SCN10A/SCN11A locus determines arrhythmic outcome., (Copyright © 2023 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Vascular Ehlers-Danlos syndrome (vEDS) is a rare genetic disorder clinically characterized by vascular, intestinal and uterine fragility and caused by heterozygous pathogenic variants in the COL3A1 gene. Management of patients with vEDS is difficult due to the unpredictability of the events and clear recommendations on the care of adults and children with vEDS are lacking. Therefore, we aimed to collect data on the current strategy of surveillance and monitoring of vEDS patients by expert centers in continental Europe and Great Britain, as a first step towards a consensus statement. A survey on the clinical management of vEDS was sent to all members of the Medium Sized Artery (MSA) Working Group of the European Reference Network for Rare Vascular Diseases (VASCERN) and other expert centers. All experts endorse the importance of monitoring patients with vEDS. Despite the absence of evidence based guidelines monitoring is considered in almost all countries, but screening intervals and modalities used for monitoring may differ among centers. There is a need for more prospective multicenter studies to define proper guidelines., (Copyright © 2022 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Filamin C (FLNC) variants are associated with cardiac and muscular phenotypes. Originally, FLNC variants were described in myofibrillar myopathy (MFM) patients. Later, high-throughput screening in cardiomyopathy cohorts determined a prominent role for FLNC in isolated hypertrophic and dilated cardiomyopathies (HCM and DCM). FLNC variants are now among the more prevalent causes of genetic DCM. FLNC-associated DCM is associated with a malignant clinical course and a high risk of sudden cardiac death. The clinical spectrum of FLNC suggests different pathomechanisms related to variant types and their location in the gene. The appropriate functioning of FLNC is crucial for structural integrity and cell signaling of the sarcomere. The secondary protein structure of FLNC is critical to ensure this function. Truncating variants with subsequent haploinsufficiency are associated with DCM and cardiac arrhythmias. Interference with the dimerization and folding of the protein leads to aggregate formation detrimental for muscle function, as found in HCM and MFM. Variants associated with HCM are predominantly missense variants, which cluster in the ROD2 domain. This domain is important for binding to the sarcomere and to ensure appropriate cell signaling. We here review FLNC genotype-phenotype correlations based on available evidence., (© 2020 The Authors. Human Mutation published by Wiley Periodicals, Inc.)

Background: Mutations in BRCA2 cause a higher risk of early-onset aggressive prostate cancer (PrCa). The IMPACT study is evaluating targeted PrCa screening using prostate-specific-antigen (PSA) in men with germline BRCA1/2 mutations., Objective: To report the utility of PSA screening, PrCa incidence, positive predictive value of PSA, biopsy, and tumour characteristics after 3 yr of screening, by BRCA status., Design, Setting, and Participants: Men aged 40-69 yr with a germline pathogenic BRCA1/2 mutation and male controls testing negative for a familial BRCA1/2 mutation were recruited. Participants underwent PSA screening for 3 yr, and if PSA > 3.0 ng/ml, men were offered prostate biopsy., Outcome Measurements and Statistical Analysis: PSA levels, PrCa incidence, and tumour characteristics were evaluated. Statistical analyses included Poisson regression offset by person-year follow-up, chi-square tests for proportion t tests for means, and Kruskal-Wallis for medians., Results and Limitations: A total of 3027 patients (2932 unique individuals) were recruited (919 BRCA1 carriers, 709 BRCA1 noncarriers, 902 BRCA2 carriers, and 497 BRCA2 noncarriers). After 3 yr of screening, 527 men had PSA > 3.0 ng/ml, 357 biopsies were performed, and 112 PrCa cases were diagnosed (31 BRCA1 carriers, 19 BRCA1 noncarriers, 47 BRCA2 carriers, and 15 BRCA2 noncarriers). Higher compliance with biopsy was observed in BRCA2 carriers compared with noncarriers (73% vs 60%). Cancer incidence rate per 1000 person years was higher in BRCA2 carriers than in noncarriers (19.4 vs 12.0; p =  0.03); BRCA2 carriers were diagnosed at a younger age (61 vs 64 yr; p =  0.04) and were more likely to have clinically significant disease than BRCA2 noncarriers (77% vs 40%; p =  0.01). No differences in age or tumour characteristics were detected between BRCA1 carriers and BRCA1 noncarriers. The 4 kallikrein marker model discriminated better (area under the curve [AUC] = 0.73) for clinically significant cancer at biopsy than PSA alone (AUC = 0.65)., Conclusions: After 3 yr of screening, compared with noncarriers, BRCA2 mutation carriers were associated with a higher incidence of PrCa, younger age of diagnosis, and clinically significant tumours. Therefore, systematic PSA screening is indicated for men with a BRCA2 mutation. Further follow-up is required to assess the role of screening in BRCA1 mutation carriers., Patient Summary: We demonstrate that after 3 yr of prostate-specific antigen (PSA) testing, we detect more serious prostate cancers in men with BRCA2 mutations than in those without these mutations. We recommend that male BRCA2 carriers are offered systematic PSA screening., (Copyright © 2019 The Authors. Published by Elsevier B.V. All rights reserved.)

The pathogenicity of previously published disease-associated genes and variants is sometimes questionable. Large-scale, population-based sequencing studies have uncovered numerous false assignments of pathogenicity. Misinterpretation of sequence variants may have serious implications for the patients and families involved, as genetic test results are increasingly being used in medical decision making. In this study, we assessed the role of the calreticulin-3 gene (CALR3) in cardiomyopathy. CALR3 has been included in several cardiomyopathy gene panels worldwide. Its inclusion is based on a single publication describing two missense variants in patients with hypertrophic cardiomyopathy. In our national cardiomyopathy cohort (n = 6154), we identified 17 unique, rare heterozygous CALR3 variants in 48 probands. Overall, our patient cohort contained a significantly higher number of rare CALR3 variants compared to the ExAC population (p = 0.0036). However, after removing a potential Dutch founder variant, no statistically significant difference was found (p = 0.89). In nine probands, the CALR3 variant was accompanied by a disease-causing variant in another, well-known cardiomyopathy gene. In three families, the CALR3 variant did not segregate with the disease. Furthermore, we could not demonstrate calreticulin-3 protein expression in myocardial tissues at various ages. On the basis of these findings, it seems highly questionable that variants in CALR3 are a monogenic cause of cardiomyopathy.

This corrects the article DOI: 10.1038/bjc.2017.429.

Background: Heritable cardiac-sodium channel dysfunction is associated with various arrhythmia syndromes, some predisposing to ventricular fibrillation. Phenotypic diversity among carriers of identical-by-descent mutations is often remarkable, suggesting influences of genetic modifiers., Objective: The purpose of this study was to identify a unique SCN5A-mutation founder population with mixed clinical phenotypes and sudden cardiac death, and to investigate the heritability of electromechanical traits besides the SCN5A-mutation effect., Methods: The 16-generation founder population segregating SCN5A c.4850&#95;4852delTCT, p.(Phe1617del), was comprehensively phenotyped. Variance component analysis was used to evaluate the mutation's effects and assess heritability., Results: In 45 p.(Phe1617del) positives, the mutation associated strongly with QTc prolongation (472 ± 60 ms vs 423 ± 35 ms in 26 mutation negatives; P <.001; odds ratio for long-QT syndrome 22.4; 95% confidence interval 4.5-224.2; P <.001) and electromechanical window (EMW) negativity (-29 ± 47 ms vs 34 ± 26 ms; P <.001). Overlapping phenotypes including conduction delay and Brugada syndrome were noted in 19. Polymorphic ventricular tachyarrhythmias occurred mostly in the daytime, after arousal-evoked heart-rate acceleration and repolarization prolongation. Cox proportional hazards regression analysis revealed female gender as an independent risk factor for cardiac events (hazard ratio 5.1; 95% confidence interval 1.6-16.3; P = .006). p.(Phe1617del) was an important determinant of QTc baseline , QTc max , and EMW, explaining 18%, 28%, and 37%, respectively, of the trait's variance. Significant heritability was observed for PQ interval (P = .003) after accounting for the p.(Phe1617del) effect., Conclusion: This SCN5A-p.(Phe1617del) founder population with phenotypic divergence and overlap reveals long-QT syndrome-related and arousal-evoked ventricular tachyarrhythmias with a female preponderance. Variance component analysis indicates additional genetic variance for PQ interval hidden in the genome, besides a dominant p.(Phe1617del) effect on QTc and EMW., (Copyright © 2017 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Dilated cardiomyopathy (DCM) is extremely heterogeneous with a large proportion due to dominantly inherited disease-causing variants in sarcomeric genes. Recessive metabolic diseases may cause DCM, usually with onset in childhood, and in the context of systemic disease. Whether metabolic defects can also cause adult-onset DCM is currently unknown. Therefore, we performed an extensive metabolic screening in 36 consecutive adult-onset DCM patients. Diagnoses were confirmed by Sanger sequencing and multiplex ligation-dependent probe amplification (MLPA). Measurement of propionyl-CoA carboxylase (PCC) activity was done in fibroblasts. Whole exome sequencing (WES) data of 157 additional DCM patients were analyzed for genetic defects. We found a metabolic profile characteristic for propionic acidemia in a patient with severe DCM from 55 years of age. Genetic analysis demonstrated compound heterozygous variants in PCCA. Enzymatic activity of PCC in fibroblasts was markedly reduced. A targeted analysis of the PCCA and PCCB genes using available WES data from 157 further DCM patients subsequently identified another patient with propionic acidemia. This patient had compound heterozygous variants in PCCB, and developed severe DCM from 42 years of age. Adult-onset DCM can be caused by propionic acidemia, an autosomal recessive inheritable metabolic disorder usually presenting as neonatal or childhood disease. Current guidelines advise a low-protein diet to ameliorate or prevent detrimental aspects of the disease. Long-term follow-up of a larger group of patients may show whether this diet would also ameliorate DCM. Our results suggest that diagnostic metabolic screening to identify propionic acidemia and related disorders in DCM patients is justified.