Publications by authors named "Lut Van Laer"

104 Publications

Clinically relevant variants in a large cohort of Indian patients with Marfan syndrome and related disorders identified by next-generation sequencing.

Sci Rep 2021 Jan 12;11(1):764. Epub 2021 Jan 12.

Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany.

Marfan syndrome and related disorders are a group of heritable connective tissue disorders and share many clinical features that involve cardiovascular, skeletal, craniofacial, ocular, and cutaneous abnormalities. The majority of affected individuals have aortopathies associated with early mortality and morbidity. Implementation of targeted gene panel next-generation sequencing in these individuals is a powerful tool to obtain a genetic diagnosis. Here, we report on clinical and genetic spectrum of 53 families from India with a total of 83 patients who had a clinical diagnosis suggestive of Marfan syndrome or related disorders. We obtained a molecular diagnosis in 45/53 (85%) index patients, in which 36/53 (68%) had rare variants in FBN1 (Marfan syndrome; 63 patients in total), seven (13.3%) in TGFBR1/TGFBR2 (Loeys-Dietz syndrome; nine patients in total) and two patients (3.7%) in SKI (Shprintzen-Goldberg syndrome). 21 of 41 rare variants (51.2%) were novel. We did not detect a disease-associated variant in 8 (15%) index patients, and none of them met the Ghent Marfan diagnostic criteria. We found the homozygous FBN1 variant p.(Arg954His) in a boy with typical features of Marfan syndrome. Our study is the first reporting on the spectrum of variants in FBN1, TGFBR1, TGFBR2, and SKI in Indian individuals.
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http://dx.doi.org/10.1038/s41598-020-80755-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7804850PMC
January 2021

Clinical characterization of the first Belgian SCN5A founder mutation cohort.

Europace 2020 Nov 22. Epub 2020 Nov 22.

Center of Medical Genetics, Faculty of Medicine and Health Sciences, University of Antwerp and Antwerp University Hospital, Prins Boudewijnlaan 43/6, 2650 Edegem, Belgium.

Aims: We identified the first Belgian SCN5A founder mutation, c.4813 + 3_4813 + 6dupGGGT. To describe the clinical spectrum and disease severity associated with this mutation, clinical data of 101 SCN5A founder mutation carriers and 46 non-mutation carrying family members from 25 Belgian families were collected.

Methods And Results: The SCN5A founder mutation was confirmed by haplotype analysis. The clinical history and electrocardiographic parameters of the mutation carriers and their family members were gathered and compared. A cardiac electrical abnormality was observed in the majority (82%) of the mutation carriers. Cardiac conduction defects, defined as PR or QRS prolongation on electrocardiogram (ECG), were most frequent, occurring in 65% of the mutation carriers. Brugada syndrome (BrS) was the second most prevalent phenotype identified in 52%, followed by atrial dysrythmia in 11%. Overall, 33% of tested mutation carriers had a normal sodium channel blocker test. Negative tests were more common in family members distantly related to the proband. Overall, 23% of the mutation carriers were symptomatic, with 8% displaying major adverse events. As many as 13% of the patients tested with a sodium blocker developed ventricular arrhythmia. One family member who did not carry the founder mutation was diagnosed with BrS.

Conclusion: The high prevalence of symptoms and sensitivity to sodium channel blockers in our founder population highlights the adverse effect of the founder mutation on cardiac conduction. The large phenotypical heterogeneity, variable penetrance, and even non-segregation suggest that other genetic (and environmental) factors modify the disease expression, severity, and outcome in these families.
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http://dx.doi.org/10.1093/europace/euaa305DOI Listing
November 2020

Enhancing rare variant interpretation in inherited arrhythmias through quantitative analysis of consortium disease cohorts and population controls.

Authors:
Roddy Walsh Najim Lahrouchi Rafik Tadros Florence Kyndt Charlotte Glinge Pieter G Postema Ahmad S Amin Eline A Nannenberg James S Ware Nicola Whiffin Francesco Mazzarotto Doris Škorić-Milosavljević Christian Krijger Elena Arbelo Dominique Babuty Hector Barajas-Martinez Britt M Beckmann Stéphane Bézieau J Martijn Bos Jeroen Breckpot Oscar Campuzano Silvia Castelletti Candan Celen Sebastian Clauss Anniek Corveleyn Lia Crotti Federica Dagradi Carlo de Asmundis Isabelle Denjoy Sven Dittmann Patrick T Ellinor Cristina Gil Ortuño Carla Giustetto Jean-Baptiste Gourraud Daisuke Hazeki Minoru Horie Taisuke Ishikawa Hideki Itoh Yoshiaki Kaneko Jørgen K Kanters Hiroki Kimoto Maria-Christina Kotta Ingrid P C Krapels Masahiko Kurabayashi Julieta Lazarte Antoine Leenhardt Bart L Loeys Catarina Lundin Takeru Makiyama Jacques Mansourati Raphaël P Martins Andrea Mazzanti Stellan Mörner Carlo Napolitano Kimie Ohkubo Michael Papadakis Boris Rudic Maria Sabater Molina Frédéric Sacher Hatice Sahin Georgia Sarquella-Brugada Regina Sebastiano Sanjay Sharma Mary N Sheppard Keiko Shimamoto M Benjamin Shoemaker Birgit Stallmeyer Johannes Steinfurt Yuji Tanaka David J Tester Keisuke Usuda Paul A van der Zwaag Sonia Van Dooren Lut Van Laer Annika Winbo Bo G Winkel Kenichiro Yamagata Sven Zumhagen Paul G A Volders Steven A Lubitz Charles Antzelevitch Pyotr G Platonov Katja E Odening Dan M Roden Jason D Roberts Jonathan R Skinner Jacob Tfelt-Hansen Maarten P van den Berg Morten S Olesen Pier D Lambiase Martin Borggrefe Kenshi Hayashi Annika Rydberg Tadashi Nakajima Masao Yoshinaga Johan B Saenen Stefan Kääb Pedro Brugada Tomas Robyns Daniela F Giachino Michael J Ackerman Ramon Brugada Josep Brugada Juan R Gimeno Can Hasdemir Pascale Guicheney Silvia G Priori Eric Schulze-Bahr Naomasa Makita Peter J Schwartz Wataru Shimizu Takeshi Aiba Jean-Jacques Schott Richard Redon Seiko Ohno Vincent Probst Elijah R Behr Julien Barc Connie R Bezzina

Genet Med 2021 Jan 7;23(1):47-58. Epub 2020 Sep 7.

Department of Clinical and Experimental Cardiology, Heart Centre, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands.

Purpose: Stringent variant interpretation guidelines can lead to high rates of variants of uncertain significance (VUS) for genetically heterogeneous disease like long QT syndrome (LQTS) and Brugada syndrome (BrS). Quantitative and disease-specific customization of American College of Medical Genetics and Genomics/Association for Molecular Pathology (ACMG/AMP) guidelines can address this false negative rate.

Methods: We compared rare variant frequencies from 1847 LQTS (KCNQ1/KCNH2/SCN5A) and 3335 BrS (SCN5A) cases from the International LQTS/BrS Genetics Consortia to population-specific gnomAD data and developed disease-specific criteria for ACMG/AMP evidence classes-rarity (PM2/BS1 rules) and case enrichment of individual (PS4) and domain-specific (PM1) variants.

Results: Rare SCN5A variant prevalence differed between European (20.8%) and Japanese (8.9%) BrS patients (p = 5.7 × 10) and diagnosis with spontaneous (28.7%) versus induced (15.8%) Brugada type 1 electrocardiogram (ECG) (p = 1.3 × 10). Ion channel transmembrane regions and specific N-terminus (KCNH2) and C-terminus (KCNQ1/KCNH2) domains were characterized by high enrichment of case variants and >95% probability of pathogenicity. Applying the customized rules, 17.4% of European BrS and 74.8% of European LQTS cases had (likely) pathogenic variants, compared with estimated diagnostic yields (case excess over gnomAD) of 19.2%/82.1%, reducing VUS prevalence to close to background rare variant frequency.

Conclusion: Large case-control data sets enable quantitative implementation of ACMG/AMP guidelines and increased sensitivity for inherited arrhythmia genetic testing.
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http://dx.doi.org/10.1038/s41436-020-00946-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7790744PMC
January 2021

Compound Heterozygous Mutations in Severe Sodium Channelopathy With Brugada Syndrome: A Case Report.

Front Cardiovasc Med 2020 24;7:117. Epub 2020 Jul 24.

Center of Medical Genetics, Antwerp University Hospital, University of Antwerp, Antwerp, Belgium.

Brugada syndrome (BrS) is an inherited cardiac arrhythmia with an increased risk for sudden cardiac death (SCD). About 20% of BrS cases are explained by mutations in the gene, encoding the main cardiac sodium Na1.5 channel. Here we present a severe case of cardiac sodium channelopathy with BrS caused by compound heterozygous mutations. We performed a genetic analysis of in a male proband who collapsed during cycling at the age of 2 years. Because of atrial standstill, he received a pacemaker, and at the age of 3 years, he experienced a collapse anew with left-sided brain stroke. A later ECG taken during a fever unmasked a characteristic BrS type-1 pattern. The functional effect of the detected genetic variants was investigated. Next-generation sequencing allowed the detection of two variants in : c.4813+3_4813+6dupGGGT-a Belgian founder mutation-and c.4711 T>C, p.Phe1571Leu. A familial segregation analysis showed the presence of the founder mutation in the proband's affected father and paternal aunt and the occurrence of the p.Phe1571Leu. The functional effect of the founder mutation was previously described as a loss-of-function. We performed a functional analysis of the p.Phe571Leu variant in HEK293 cells alone or co-expressed with the β-subunit. Compared to the wild type, p.Phe1571Leu displayed a hyperpolarizing shift in the voltage dependence of inactivation (loss-of-function), while the activation parameters were unaffected. Using the peptide toxin nemertide α-1, the variant's loss-of-function effect could be restored due to a toxin-dependent reduction of channel inactivation. This is the first report providing support for the pathogenicity of the p.Phe1571Leu variant which, together with the c.4813+3_4813+6dupGGGT founder mutation, explains the severity of the phenotype of cardiac sodium channelopathy with BrS in the presented case.
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http://dx.doi.org/10.3389/fcvm.2020.00117DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7396896PMC
July 2020

Cardiogeneticsbank@UZA: A Collection of DNA, Tissues, and Cell Lines as a Translational Tool.

Front Med (Lausanne) 2019 6;6:198. Epub 2019 Sep 6.

Center of Medical Genetics, Antwerp University Hospital, University of Antwerp, Antwerp, Belgium.

Cardiogeneticsbank@UZA is an academic hospital integrated biobank that collects aortic tissue, blood, cell lines (fibroblasts, vascular smooth muscle cells, peripheral blood mononuclear cells, and induced pluripotent stem cells), and DNA from patients with cardiogenetic disorders, for both diagnostic and research purposes. We adhere to a quality management system and have established standard protocols for the sampling and processing of all cardiogenetic patient related materials. Cardiogeneticsbank@UZA is embedded in the Biobanking and Biomolecular Resources Research Infrastructure Belgium (BBMRI.be) and samples from this biobank are available for commercial and academic researchers, through an established access procedure. Currently, the extremely valuable cardiogenetics collection consists of more than 8,700 DNA samples, 380 tissue samples, and 500 cell lines of 7,578 patients, and is linked with extensive clinical data. Some interesting potential research applications are discussed.
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http://dx.doi.org/10.3389/fmed.2019.00198DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6742711PMC
September 2019

Copy number variation analysis in bicuspid aortic valve-related aortopathy identifies TBX20 as a contributing gene.

Eur J Hum Genet 2019 07 28;27(7):1033-1043. Epub 2019 Feb 28.

Centre of Medical Genetics, Faculty of Medicine and Health Sciences, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium.

Bicuspid aortic valve (BAV) is the most common congenital heart defect (CHD), affecting 1-2% of the population. BAV is associated with thoracic aortic aneurysms (TAAs). Deleterious copy number variations (CNVs) were found previously in up to 10% of CHD cases. This study aimed at unravelling the contribution of deleterious deletions or duplications in 95 unrelated BAV/TAA patients. Seven unique or rare CNVs were validated, harbouring protein-coding genes with a role in the cardiovascular system. Based on the presence of overlapping CNVs in patients with cardiovascular phenotypes in the DECIPHER database, the identification of similar CNVs in whole-exome sequencing data of 67 BAV/TAA patients and suggested topological domain involvement from Hi-C data, supportive evidence was obtained for two genes (DGCR6 and TBX20) of the seven initially validated CNVs. A rare variant burden analysis using next-generation sequencing data from 637 BAV/TAA patients was performed for these two candidate genes. This revealed a suggestive genetic role for TBX20 in BAV/TAA aetiology, further reinforced by segregation of a rare TBX20 variant with the phenotype within a BAV/TAA family. To conclude, our results do not confirm a significant contribution for deleterious CNVs in BAV/TAA as only one potentially pathogenic CNV (1.05%) was identified. We cannot exclude the possibility that BAV/TAA is occasionally attributed to causal CNVs though, or that certain CNVs act as genetic risk factors by creating a sensitised background for BAV/TAA. Finally, accumulative evidence for TBX20 involvement in BAV/TAA aetiology underlines the importance of this transcription factor in cardiovascular disease.
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http://dx.doi.org/10.1038/s41431-019-0364-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6777542PMC
July 2019

Confirmation of the role of pathogenic SMAD6 variants in bicuspid aortic valve-related aortopathy.

Eur J Hum Genet 2019 07 22;27(7):1044-1053. Epub 2019 Feb 22.

Center of Medical Genetics, Faculty of Medicine and Health Sciences, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium.

Progressive dilatation of the thoracic aorta leads to thoracic aortic aneurysm (TAA), which is often asymptomatic but predisposes to lethal aortic dissections and ruptures. TAA is a common complication in patients with bicuspid aortic valve (BAV). Recently, rare loss-of-function SMAD6 variants were shown to contribute significantly to the genetic aetiology of BAV/TAA. Intriguingly, patients with craniosynostosis have also been reported to be explained molecularly by similar loss-of-function SMAD6 variants. While significantly reduced penetrance of craniosynostosis has been reported for the SMAD6 variants as such, near-complete penetrance is reached upon co-occurrence with a common BMP2 SNP risk allele. Here, we report on the results of a SMAD6-variant analysis in 473 unrelated non-syndromic TAA patients, of which the SMAD6-positive individuals were also studied for the presence of the BMP2 risk allele. Although only 14% of the TAA patients also presented BAV, all novel likely pathogenic SMAD6 variants (N = 7) were identified in BAV/TAA individuals, further establishing the role of SMAD6 variants to the aetiology of BAV/TAA and revealing limited contribution to TAA development in patients with a tricuspid aortic valve. Familial segregation studies confirmed reduced penetrance (82%) and variable clinical expressivity, with coarctation of the aorta being a common comorbidity. None of our six BMP2+/SMAD6+ patients presented with craniosynostosis. Hence, the proposed digenic model for craniosynostosis was not supported in the presented BAV/TAA cohort, suggesting that additional factors are at play. Finally, our data provide improved insights into the clinical spectrum of SMAD6-related BAV/TAA and has important implications for molecular diagnostics.
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http://dx.doi.org/10.1038/s41431-019-0363-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6777625PMC
July 2019

Aortic aneurysm/dissection and osteogenesis imperfecta: Four new families and review of the literature.

Bone 2019 04 23;121:191-195. Epub 2019 Jan 23.

Center for Medical Genetics, University of Antwerp/Antwerp University Hospital, Antwerp, Belgium; Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands.

Osteogenesis imperfecta (OI) is the commonest form of heritable bone fragility. It is mainly characterized by fractures, hearing loss and dentinogenesis imperfecta. OI patients are at increased risk of cardiovascular disease of variable severity. Aortic aneurysm/dissection is one of the rarer but potentially serious cardiovascular complications of OI. So far, only six patients with aortic dissection and OI have been reported. As such, present OI diagnostic guidelines do not recommend systematic screening of patients for aortopathy. Here, we report on the clinical and molecular characteristics of three new OI patients and one additional patient with a first degree relative who presented with aortic dissection and/or aneurysm surgery. This observation further opens up the discussion on the need for and extent of cardiovascular screening in adult patients with OI.
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http://dx.doi.org/10.1016/j.bone.2019.01.022DOI Listing
April 2019

ROBO4 variants predispose individuals to bicuspid aortic valve and thoracic aortic aneurysm.

Nat Genet 2019 01 19;51(1):42-50. Epub 2018 Nov 19.

McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA.

Bicuspid aortic valve (BAV) is a common congenital heart defect (population incidence, 1-2%) that frequently presents with ascending aortic aneurysm (AscAA). BAV/AscAA shows autosomal dominant inheritance with incomplete penetrance and male predominance. Causative gene mutations (for example, NOTCH1, SMAD6) are known for ≤1% of nonsyndromic BAV cases with and without AscAA, impeding mechanistic insight and development of therapeutic strategies. Here, we report the identification of variants in ROBO4 (which encodes a factor known to contribute to endothelial performance) that segregate with disease in two families. Targeted sequencing of ROBO4 showed enrichment for rare variants in BAV/AscAA probands compared with controls. Targeted silencing of ROBO4 or mutant ROBO4 expression in endothelial cell lines results in impaired barrier function and a synthetic repertoire suggestive of endothelial-to-mesenchymal transition. This is consistent with BAV/AscAA-associated findings in patients and in animal models deficient for ROBO4. These data identify a novel endothelial etiology for this common human disease phenotype.
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http://dx.doi.org/10.1038/s41588-018-0265-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6309588PMC
January 2019

Spontaneous Coronary Artery Dissection in a Man With a Novel Missense Mutation in SMAD2 Treated by Optical Coherence Tomography-Guided Percutaneous Coronary Intervention.

JACC Cardiovasc Interv 2019 Mar 15;12(6):e45-e47. Epub 2018 Nov 15.

Department of Cardiology, Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel, Brussels, Belgium; Antwerp Cardiovascular Center, ZNA Middelheim, Antwerp, Belgium.

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http://dx.doi.org/10.1016/j.jcin.2018.09.007DOI Listing
March 2019

Correction: Arterial tortuosity syndrome: 40 new families and literature review.

Genet Med 2019 Aug;21(8):1894-1895

Center For Medical Genetics Ghent, Ghent University Hospital, Ghent, Belgium.

In the published version of this paper the author Neus Baena's name was incorrectly given as Neus Baena Diez. This has now been corrected in both the HTML and PDF versions of the paper.
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http://dx.doi.org/10.1038/s41436-018-0035-3DOI Listing
August 2019

FLNA mutations in surviving males presenting with connective tissue findings: two new case reports and review of the literature.

BMC Med Genet 2018 08 8;19(1):140. Epub 2018 Aug 8.

Center of Medical Genetics, Faculty of Medicine and Health Sciences, University of Antwerp and Antwerp University Hospital, Prins Boudewijnlaan 43, 2650, Antwerp, Belgium.

Background: Mutations in the X-linked gene filamin A (FLNA), encoding the actin-binding protein FLNA, cause a wide spectrum of connective tissue, skeletal, cardiovascular and/or gastrointestinal manifestations. Males are typically more severely affected than females with common pre- or perinatal death.

Case Presentation: We provide a genotype- and phenotype-oriented literature overview of FLNA hemizygous mutations and report on two live-born male FLNA mutation carriers. Firstly, we identified a de novo, missense mutation (c.238C > G, p.(Leu80Val)) in a five-year old Indian boy who presented with periventricular nodular heterotopia, increased skin laxity, joint hypermobility, mitral valve prolapse with regurgitation and marked facial features (e.g. a flat face, orbital fullness, upslanting palpebral fissures and low-set ears). Secondly, we identified two cis-located FLNA mutations (c.7921C > G, p.(Pro2641Ala); c.7923delC, p.(Tyr2642Thrfs*63)) in a Bosnian patient with Ehlers-Danlos syndrome-like features such as skin translucency and joint hypermobility. This patient also presented with brain anomalies, pectus excavatum, mitral valve prolapse, pulmonary hypertension and dilatation of the pulmonary arteries. He died from heart failure in his second year of life.

Conclusions: These two new cases expand the list of live-born FLNA mutation-positive males with connective tissue disease from eight to ten, contributing to a better knowledge of the genetic and phenotypic spectrum of FLNA-related disease.
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http://dx.doi.org/10.1186/s12881-018-0655-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6083619PMC
August 2018

Clinical Validity of Genes for Heritable Thoracic Aortic Aneurysm and Dissection.

J Am Coll Cardiol 2018 08;72(6):605-615

Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium; Department of Cardiology, Ghent University Hospital, Ghent, Belgium. Electronic address:

Background: Thoracic aortic aneurysms progressively enlarge and predispose to acute aortic dissections. Up to 25% of individuals with thoracic aortic disease harbor an underlying Mendelian pathogenic variant. An evidence-based strategy for selection of genes to test in hereditary thoracic aortic aneurysm and dissection (HTAAD) helps inform family screening and intervention to prevent life-threatening thoracic aortic events.

Objectives: The purpose of this study was to accurately identify genes that predispose to HTAAD using the Clinical Genome Resource (ClinGen) framework.

Methods: We applied the semiquantitative ClinGen framework to assess presumed gene-disease relationships between 53 candidate genes and HTAAD. Genes were classified as causative for HTAAD if they were associated with isolated thoracic aortic disease and were clinically actionable, triggering routine aortic surveillance, intervention, and family cascade screening. All gene-disease assertions were evaluated by a pre-defined curator-expert pair and subsequently discussed with an expert panel.

Results: Genes were classified based on the strength of association with HTAAD into 5 categories: definitive (n = 9), strong (n = 2), moderate (n = 4), limited (n = 15), and no reported evidence (n = 23). They were further categorized by severity of associated aortic disease and risk of progression. Eleven genes in the definitive and strong groups were designated as "HTAAD genes" (category A). Eight genes were classified as unlikely to be progressive (category B) and 4 as low risk (category C). The remaining genes were recent genes with an uncertain classification or genes with no evidence of association with HTAAD.

Conclusions: The ClinGen framework is useful to semiquantitatively assess the strength of gene-disease relationships for HTAAD. Gene categories resulting from the curation may inform clinical laboratories in the development, interpretation, and subsequent clinical implications of genetic testing for patients with aortic disease.
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http://dx.doi.org/10.1016/j.jacc.2018.04.089DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6378369PMC
August 2018

Bi-allelic Loss-of-Function Mutations in the NPR-C Receptor Result in Enhanced Growth and Connective Tissue Abnormalities.

Am J Hum Genet 2018 08 19;103(2):288-295. Epub 2018 Jul 19.

Center of Medical Genetics, University of Antwerp and Antwerp University Hospital, 2650 Edegem, Belgium. Electronic address:

The natriuretic peptide signaling pathway has been implicated in many cellular processes, including endochondral ossification and bone growth. More precisely, different mutations in the NPR-B receptor and the CNP ligand have been identified in individuals with either short or tall stature. In this study we show that the NPR-C receptor (encoded by NPR3) is also important for the regulation of linear bone growth. We report four individuals, originating from three different families, with a phenotype characterized by tall stature, long digits, and extra epiphyses in the hands and feet. In addition, aortic dilatation was observed in two of these families. In each affected individual, we identified a bi-allelic loss-of-function mutation in NPR3. The missense mutations (c.442T>C [p.Ser148Pro] and c.1088A>T [p.Asp363Val]) resulted in intracellular retention of the NPR-C receptor and absent localization on the plasma membrane, whereas the nonsense mutation (c.1524delC [p.Tyr508]) resulted in nonsense-mediated mRNA decay. Biochemical analysis of plasma from two affected and unrelated individuals revealed a reduced NTproNP/NP ratio for all ligands and also high cGMP levels. These data strongly suggest a reduced clearance of natriuretic peptides by the defective NPR-C receptor and consequently increased activity of the NPR-A/B receptors. In conclusion, this study demonstrates that loss-of-function mutations in NPR3 result in increased NPR-A/B signaling activity and cause a phenotype marked by enhanced bone growth and cardiovascular abnormalities.
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http://dx.doi.org/10.1016/j.ajhg.2018.06.007DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6080727PMC
August 2018

Novel pathogenic variants in five families with arterial aneurysm and dissection: further delineation of the phenotype.

J Med Genet 2019 04 2;56(4):220-227. Epub 2018 Jul 2.

Center of Medical Genetics, Faculty of Medicine and Health Sciences, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium.

Background: Missense variants in , encoding a key transcriptional regulator of transforming growth factor beta signalling, were recently reported to cause arterial aneurysmal disease.

Objectives: The aims of the study were to identify the genetic disease cause in families with aortic/arterial aneurysmal disease and to further define genotype-phenotype correlations.

Methods And Results: Using gene panel sequencing, we identified a nonsense variant and four missense variants, all affecting highly conserved amino acids in the MH2 domain. The premature stop codon (c.612dup; p.(Asn205*)) was identified in a marfanoid patient with aortic root dilatation and in his affected father. A p.(Asn318Lys) missense variant was found in a Marfan syndrome (MFS)-like case who presented with aortic root aneurysm and in her affected daughter with marfanoid features and mild aortic dilatation. In a man clinically diagnosed with Loeys-Dietz syndrome (LDS) that presents with aortic root dilatation and marked tortuosity of the neck vessels, another missense variant, p.(Ser397Tyr), was identified. This variant was also found in his affected daughter with hypertelorism and arterial tortuosity, as well as his affected mother. The third missense variant, p.(Asn361Thr), was discovered in a man presenting with coronary artery dissection. Variant genotyping in three unaffected family members confirmed its absence. The last missense variant, p.(Ser467Leu), was identified in a man with significant cardiovascular and connective tissue involvement.

Conclusion: Taken together, our data suggest that heterozygous loss-of-function variants can cause a wide spectrum of autosomal dominant aortic and arterial aneurysmal disease, combined with connective tissue findings reminiscent of MFS and LDS.
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http://dx.doi.org/10.1136/jmedgenet-2018-105304DOI Listing
April 2019

Elucidating the genetic architecture of Adams-Oliver syndrome in a large European cohort.

Hum Mutat 2018 09 4;39(9):1246-1261. Epub 2018 Jul 4.

Center of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium.

Adams-Oliver syndrome (AOS) is a rare developmental disorder, characterized by scalp aplasia cutis congenita (ACC) and transverse terminal limb defects (TTLD). Autosomal dominant forms of AOS are linked to mutations in ARHGAP31, DLL4, NOTCH1 or RBPJ, while DOCK6 and EOGT underlie autosomal recessive inheritance. Data on the frequency and distribution of mutations in large cohorts are currently limited. The purpose of this study was therefore to comprehensively examine the genetic architecture of AOS in an extensive cohort. Molecular diagnostic screening of 194 AOS/ACC/TTLD probands/families was conducted using next-generation and/or capillary sequencing analyses. In total, we identified 63 (likely) pathogenic mutations, comprising 56 distinct and 22 novel mutations, providing a molecular diagnosis in 30% of patients. Taken together with previous reports, these findings bring the total number of reported disease variants to 63, with a diagnostic yield of 36% in familial cases. NOTCH1 is the major contributor, underlying 10% of AOS/ACC/TTLD cases, with DLL4 (6%), DOCK6 (6%), ARHGAP31 (3%), EOGT (3%), and RBPJ (2%) representing additional causality in this cohort. We confirm the relevance of genetic screening across the AOS/ACC/TTLD spectrum, highlighting preliminary but important genotype-phenotype correlations. This cohort offers potential for further gene identification to address missing heritability.
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http://dx.doi.org/10.1002/humu.23567DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6175364PMC
September 2018

Identification and characterization of a novel FBN1 gene variant in an extended family with variable clinical phenotype of Marfan syndrome.

Connect Tissue Res 2019 03 28;60(2):146-154. Epub 2018 May 28.

h Department of Histology and Embryology , Uludağ University , Bursa , Turkey.

Marfan syndrome (MFS) is a multi-systemic autosomal dominant condition caused by mutations in the gene (FBN1) coding for fibrillin-1. Mutations have been associated with a wide range of overlapping phenotypes. Here, we report on an extended family presenting with skeletal, ocular and cardiovascular clinical features. The 37-year-old male propositus, who had chest pain, dyspnea and shortness of breath, was first diagnosed based on the revised Ghent criteria and then subjected to molecular genetic analyses. FBN1 sequencing of the proband as well as available affected family members revealed the presence of a novel variant, c.7828G>C (p.Glu2610Gln), which was not present in any of the unaffected family members. In silico analyses demonstrated that the Glu2610 residue is part of the conserved DINE motif found at the beginning of each cbEGF domain of FBN1. The substitution of Glu2610 with Gln decreased fibrillin-1 production accordingly. Despite the fact that this variation appears to be primarily responsible for the etiology of MFS in the present family, our findings suggest that variable clinical expressions of the disease phenotype should be considered critically by the physicians.
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http://dx.doi.org/10.1080/03008207.2018.1472589DOI Listing
March 2019

pBRIT: gene prioritization by correlating functional and phenotypic annotations through integrative data fusion.

Bioinformatics 2018 07;34(13):2254-2262

Center of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium.

Motivation: Computational gene prioritization can aid in disease gene identification. Here, we propose pBRIT (prioritization using Bayesian Ridge regression and Information Theoretic model), a novel adaptive and scalable prioritization tool, integrating Pubmed abstracts, Gene Ontology, Sequence similarities, Mammalian and Human Phenotype Ontology, Pathway, Interactions, Disease Ontology, Gene Association database and Human Genome Epidemiology database, into the prediction model. We explore and address effects of sparsity and inter-feature dependencies within annotation sources, and the impact of bias towards specific annotations.

Results: pBRIT models feature dependencies and sparsity by an Information-Theoretic (data driven) approach and applies intermediate integration based data fusion. Following the hypothesis that genes underlying similar diseases will share functional and phenotype characteristics, it incorporates Bayesian Ridge regression to learn a linear mapping between functional and phenotype annotations. Genes are prioritized on phenotypic concordance to the training genes. We evaluated pBRIT against nine existing methods, and on over 2000 HPO-gene associations retrieved after construction of pBRIT data sources. We achieve maximum AUC scores ranging from 0.92 to 0.96 against benchmark datasets and of 0.80 against the time-stamped HPO entries, indicating good performance with high sensitivity and specificity. Our model shows stable performance with regard to changes in the underlying annotation data, is fast and scalable for implementation in routine pipelines.

Availability And Implementation: http://biomina.be/apps/pbrit/; https://bitbucket.org/medgenua/pbrit.

Supplementary Information: Supplementary data are available at Bioinformatics online.
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http://dx.doi.org/10.1093/bioinformatics/bty079DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6022555PMC
July 2018

A mutation update on the LDS-associated genes TGFB2/3 and SMAD2/3.

Hum Mutat 2018 05 6;39(5):621-634. Epub 2018 Mar 6.

Center of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium.

The Loeys-Dietz syndrome (LDS) is a connective tissue disorder affecting the cardiovascular, skeletal, and ocular system. Most typically, LDS patients present with aortic aneurysms and arterial tortuosity, hypertelorism, and bifid/broad uvula or cleft palate. Initially, mutations in transforming growth factor-β (TGF-β) receptors (TGFBR1 and TGFBR2) were described to cause LDS, hereby leading to impaired TGF-β signaling. More recently, TGF-β ligands, TGFB2 and TGFB3, as well as intracellular downstream effectors of the TGF-β pathway, SMAD2 and SMAD3, were shown to be involved in LDS. This emphasizes the role of disturbed TGF-β signaling in LDS pathogenesis. Since most literature so far has focused on TGFBR1/2, we provide a comprehensive review on the known and some novel TGFB2/3 and SMAD2/3 mutations. For TGFB2 and SMAD3, the clinical manifestations, both of the patients previously described in the literature and our newly reported patients, are summarized in detail. This clearly indicates that LDS concerns a disorder with a broad phenotypical spectrum that is still emerging as more patients will be identified. All mutations described here are present in the corresponding Leiden Open Variant Database.
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http://dx.doi.org/10.1002/humu.23407DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5947146PMC
May 2018

Arterial tortuosity syndrome: 40 new families and literature review.

Genet Med 2018 10 11;20(10):1236-1245. Epub 2018 Jan 11.

Center For Medical Genetics Ghent, Ghent University Hospital, Ghent, Belgium.

Purpose: We delineate the clinical spectrum and describe the histology in arterial tortuosity syndrome (ATS), a rare connective tissue disorder characterized by tortuosity of the large and medium-sized arteries, caused by mutations in SLC2A10.

Methods: We retrospectively characterized 40 novel ATS families (50 patients) and reviewed the 52 previously reported patients. We performed histology and electron microscopy (EM) on skin and vascular biopsies and evaluated TGF-β signaling with immunohistochemistry for pSMAD2 and CTGF.

Results: Stenoses, tortuosity, and aneurysm formation are widespread occurrences. Severe but rare vascular complications include early and aggressive aortic root aneurysms, neonatal intracranial bleeding, ischemic stroke, and gastric perforation. Thus far, no reports unequivocally document vascular dissections or ruptures. Of note, diaphragmatic hernia and infant respiratory distress syndrome (IRDS) are frequently observed. Skin and vascular biopsies show fragmented elastic fibers (EF) and increased collagen deposition. EM of skin EF shows a fragmented elastin core and a peripheral mantle of microfibrils of random directionality. Skin and end-stage diseased vascular tissue do not indicate increased TGF-β signaling.

Conclusion: Our findings warrant attention for IRDS and diaphragmatic hernia, close monitoring of the aortic root early in life, and extensive vascular imaging afterwards. EM on skin biopsies shows disease-specific abnormalities.
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http://dx.doi.org/10.1038/gim.2017.253DOI Listing
October 2018

Differences in manifestations of Marfan syndrome, Ehlers-Danlos syndrome, and Loeys-Dietz syndrome.

Ann Cardiothorac Surg 2017 Nov;6(6):582-594

Center of Medical Genetics, Faculty of Medicine and Health Sciences, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium.

Many different heritable connective tissue disorders (HCTD) have been described over the past decades. These syndromes often affect the connective tissue of various organ systems, including heart, blood vessels, skin, joints, bone, eyes, and lungs. The discovery of these HCTD was followed by the identification of mutations in a wide range of genes encoding structural proteins, modifying enzymes, or components of the TGFβ-signaling pathway. Three typical examples of HCTD are Marfan syndrome (MFS), Ehlers-Danlos syndrome (EDS), and Loeys-Dietz syndrome (LDS). These syndromes show some degree of phenotypical overlap of cardiovascular, skeletal, and cutaneous features. MFS is typically characterized by cardiovascular, ocular, and skeletal manifestations and is caused by heterozygous mutations in , coding for the extracellular matrix (ECM) protein fibrillin-1. The most common cardiovascular phenotype involves aortic aneurysm and dissection at the sinuses of Valsalva. LDS is caused by mutations in , , or , all coding for components of the TGFβ-signaling pathway. LDS can be distinguished from MFS by the unique presence of hypertelorism, bifid uvula or cleft palate, and widespread aortic and arterial aneurysm and tortuosity. Compared to MFS, LDS cardiovascular manifestations tend to be more severe. In contrast, no association is reported between LDS and the presence of ectopia lentis, a key distinguishing feature of MFS. Overlapping features between MFS and LDS include scoliosis, pes planus, anterior chest deformity, spontaneous pneumothorax, and dural ectasia. EDS refers to a group of clinically and genetically heterogeneous connective tissue disorders and all subtypes are characterized by variable abnormalities of skin, ligaments and joints, blood vessels, and internal organs. Typical presenting features include joint hypermobility, skin hyperextensibility, and tissue fragility. Up to one quarter of the EDS patients show aortic aneurysmal disease. The latest EDS nosology distinguishes 13 subtypes. Many phenotypic features show overlap between the different subtypes, which makes the clinical diagnosis rather difficult and highlights the importance of molecular diagnostic confirmation.
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http://dx.doi.org/10.21037/acs.2017.11.03DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5721110PMC
November 2017

Left ventricular non-compaction with Ebstein anomaly attributed to a TPM1 mutation.

Eur J Med Genet 2018 Jan 9;61(1):8-10. Epub 2017 Oct 9.

Center of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium. Electronic address:

Left ventricular non-compaction (cardiomyopathy) (LVN(C)) is a rare hereditary cardiac condition, resulting from abnormal embryonic myocardial development. While it mostly occurs as an isolated condition, association with other cardiovascular manifestations such as Ebstein anomaly (EA) has been reported. This congenital heart defect is characterized by downward displacement of the tricuspid valve and leads to diminished ventricular size and function. In an autosomal dominant LVN(C) family consisting of five affected individuals, of which two also presented with EA and three with mitral valve insufficiency, we pursued the genetic disease cause using whole exome sequencing (WES). WES revealed a missense variant (p.Leu113Val) in TPM1 segregating with the LVN(C) phenotype. TPM1 encodes α-tropomyosin, which is involved in myocardial contraction, as well as in stabilization of non-muscle cytoskeletal actin filaments. So far, LVN(C)-EA has predominantly been linked to pathogenic variants in MYH7. However, one sporadic LVN(C)-EA case with a de novo TPM1 variant has recently been described. We here report the first LVN(C)-EA family segregating a pathogenic TPM1 variant, further establishing the association between EA predisposition and TPM1-related LVN(C). Consequently, we recommend genetic testing for both MYH7 and TPM1 in patients or families in which LVN(C)/non-compaction and EA coincide.
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http://dx.doi.org/10.1016/j.ejmg.2017.10.003DOI Listing
January 2018

Inborn errors in RNA polymerase III underlie severe varicella zoster virus infections.

J Clin Invest 2017 Sep 7;127(9):3543-3556. Epub 2017 Aug 7.

Department of Infectious Diseases, Aarhus University Hospital Skejby, Aarhus, Denmark.

Varicella zoster virus (VZV) typically causes chickenpox upon primary infection. In rare cases, VZV can give rise to life-threatening disease in otherwise healthy people, but the immunological basis for this remains unexplained. We report 4 cases of acute severe VZV infection affecting the central nervous system or the lungs in unrelated, otherwise healthy children who are heterozygous for rare missense mutations in POLR3A (one patient), POLR3C (one patient), or both (two patients). POLR3A and POLR3C encode subunits of RNA polymerase III. Leukocytes from all 4 patients tested exhibited poor IFN induction in response to synthetic or VZV-derived DNA. Moreover, leukocytes from 3 of the patients displayed defective IFN production upon VZV infection and reduced control of VZV replication. These phenotypes were rescued by transduction with relevant WT alleles. This work demonstrates that monogenic or digenic POLR3A and POLR3C deficiencies confer increased susceptibility to severe VZV disease in otherwise healthy children, providing evidence for an essential role of a DNA sensor in human immunity.
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http://dx.doi.org/10.1172/JCI92280DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5669568PMC
September 2017

Candidate Gene Resequencing in a Large Bicuspid Aortic Valve-Associated Thoracic Aortic Aneurysm Cohort: as an Important Contributor.

Front Physiol 2017 13;8:400. Epub 2017 Jun 13.

Faculty of Medicine and Health Sciences, Center of Medical Genetics, University of Antwerp and Antwerp University HospitalAntwerp, Belgium.

Bicuspid aortic valve (BAV) is the most common congenital heart defect. Although many BAV patients remain asymptomatic, at least 20% develop thoracic aortic aneurysm (TAA). Historically, BAV-related TAA was considered as a hemodynamic consequence of the valve defect. Multiple lines of evidence currently suggest that genetic determinants contribute to the pathogenesis of both BAV and TAA in affected individuals. Despite high heritability, only very few genes have been linked to BAV or BAV/TAA, such as , and . Moreover, they only explain a minority of patients. Other candidate genes have been suggested based on the presence of BAV in knockout mouse models (e.g., ) or in syndromic (e.g., ) or non-syndromic (e.g., ) TAA forms. We hypothesized that rare genetic variants in these genes may be enriched in patients presenting with both BAV and TAA. We performed targeted resequencing of 22 candidate genes using Haloplex target enrichment in a strictly defined BAV/TAA cohort ( = 441; BAV in addition to an aortic root or ascendens diameter ≥ 4.0 cm in adults, or a Z-score ≥ 3 in children) and in a collection of healthy controls with normal echocardiographic evaluation ( = 183). After additional burden analysis against the Exome Aggregation Consortium database, the strongest candidate susceptibility gene was ( = 0.002), with 2.5% ( = 11) of BAV/TAA patients harboring causal variants, including two nonsense, one in-frame deletion and two frameshift mutations. All six missense mutations were located in the functionally important MH1 and MH2 domains. In conclusion, we report a significant contribution of mutations to the etiology of the BAV/TAA phenotype.
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http://dx.doi.org/10.3389/fphys.2017.00400DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5469151PMC
June 2017

Targeted Next-Generation Sequencing of 51 Genes Involved in Primary Electrical Disease.

J Mol Diagn 2017 05 22;19(3):445-459. Epub 2017 Mar 22.

Center of Medical Genetics, Faculty of Medicine and Health Sciences, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium. Electronic address:

Primary electrical disease (PED) is characterized by cardiac arrhythmias, which can lead to sudden cardiac death in the absence of detectable structural heart disease. PED encompasses a diversity of inherited syndromes, predominantly Brugada syndrome, early repolarization syndrome, long QT syndrome, short QT syndrome, arrhythmogenic right ventricular cardiomyopathy, and catecholaminergic polymorphic ventricular tachycardia. To overcome the diagnostic challenges imposed by the clinical and genetic heterogeneity of PED, we developed a targeted gene panel for next-generation sequencing of 51 PED genes. The amplified samples were sequenced on MiSeq. To validate the panel, 20 Human Polymorphism Study Center samples and 19 positive control samples were used, with a total of 1479 variants. An analytical sensitivity and specificity of 100% and 99.9% were obtained. After validation, we applied the assay to 114 PED patients. We identified 107 variants in 36 different genes, 18 of which were classified as pathogenic or likely pathogenic, 54 variants were of unknown significance, and 35 were classified as likely benign. We can conclude that the PED Multiplex Amplification of Specific Targets for Resequencing Plus assay is a proficient and highly reliable test to routinely screen patients experiencing primary arrhythmias.
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http://dx.doi.org/10.1016/j.jmoldx.2017.01.010DOI Listing
May 2017

Identification of FBN1 gene mutations in Ukrainian Marfan syndrome patients.

Genet Res (Camb) 2016 10 11;98:e13. Epub 2016 Oct 11.

Center of Medical Genetics,Faculty of Medicine and Health Sciences,University of Antwerp and Antwerp University Hospital,Antwerp,Belgium.

Marfan syndrome is an autosomal dominant connective tissue disorder, predominantly affecting the ocular, skeletal and cardiovascular systems. Here, we present the results of the first genetic testing in 40 Ukrainian Marfan (-like) patients and 10 relatives. We applied a targeted next generation sequencing panel comprising FBN1 and 13 thoracic aortic aneurysm genes. We identified 27 causal mutations in FBN1, obtaining a mutation yield of 67·5%. A significant difference in age at aortic surgery between mutation positive and negative patients was observed. Thus, we conclude that genetic testing is important to identify patients at higher risk for developing life-threatening cardiovascular complications.
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http://dx.doi.org/10.1017/S0016672316000112DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6865158PMC
October 2016

Loss-of-function mutations in the X-linked biglycan gene cause a severe syndromic form of thoracic aortic aneurysms and dissections.

Genet Med 2017 04 15;19(4):386-395. Epub 2016 Sep 15.

Center of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium.

Purpose: Thoracic aortic aneurysm and dissection (TAAD) is typically inherited in an autosomal dominant manner, but rare X-linked families have been described. So far, the only known X-linked gene is FLNA, which is associated with the periventricular nodular heterotopia type of Ehlers-Danlos syndrome. However, mutations in this gene explain only a small number of X-linked TAAD families.

Methods: We performed targeted resequencing of 368 candidate genes in a cohort of 11 molecularly unexplained Marfan probands. Subsequently, Sanger sequencing of BGN in 360 male and 155 female molecularly unexplained TAAD probands was performed.

Results: We found five individuals with loss-of-function mutations in BGN encoding the small leucine-rich proteoglycan biglycan. The clinical phenotype is characterized by early-onset aortic aneurysm and dissection. Other recurrent findings include hypertelorism, pectus deformity, joint hypermobility, contractures, and mild skeletal dysplasia. Fluorescent staining revealed an increase in TGF-β signaling, evidenced by an increase in nuclear pSMAD2 in the aortic wall. Our results are in line with those of prior reports demonstrating that Bgn-deficient male BALB/cA mice die from aortic rupture.

Conclusion: In conclusion, BGN gene defects in humans cause an X-linked syndromic form of severe TAAD that is associated with preservation of elastic fibers and increased TGF-β signaling.Genet Med 19 4, 386-395.
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http://dx.doi.org/10.1038/gim.2016.126DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5207316PMC
April 2017

Heterozygous Loss-of-Function SEC61A1 Mutations Cause Autosomal-Dominant Tubulo-Interstitial and Glomerulocystic Kidney Disease with Anemia.

Am J Hum Genet 2016 Jul;99(1):174-87

Center of Medical Genetics, Faculty of Medicine and Health Sciences, University of Antwerp and Antwerp University Hospital, Antwerp 2650, Belgium; Department of Human Genetics, Radboud University Medical Centre, 6500 HB Nijmegen, the Netherlands. Electronic address:

Autosomal-dominant tubulo-interstitial kidney disease (ADTKD) encompasses a group of disorders characterized by renal tubular and interstitial abnormalities, leading to slow progressive loss of kidney function requiring dialysis and kidney transplantation. Mutations in UMOD, MUC1, and REN are responsible for many, but not all, cases of ADTKD. We report on two families with ADTKD and congenital anemia accompanied by either intrauterine growth retardation or neutropenia. Ultrasound and kidney biopsy revealed small dysplastic kidneys with cysts and tubular atrophy with secondary glomerular sclerosis, respectively. Exclusion of known ADTKD genes coupled with linkage analysis, whole-exome sequencing, and targeted re-sequencing identified heterozygous missense variants in SEC61A1-c.553A>G (p.Thr185Ala) and c.200T>G (p.Val67Gly)-both affecting functionally important and conserved residues in SEC61. Both transiently expressed SEC6A1A variants are delocalized to the Golgi, a finding confirmed in a renal biopsy from an affected individual. Suppression or CRISPR-mediated deletions of sec61al2 in zebrafish embryos induced convolution defects of the pronephric tubules but not the pronephric ducts, consistent with the tubular atrophy observed in the affected individuals. Human mRNA encoding either of the two pathogenic alleles failed to rescue this phenotype as opposed to a complete rescue by human wild-type mRNA. Taken together, these findings provide a mechanism by which mutations in SEC61A1 lead to an autosomal-dominant syndromic form of progressive chronic kidney disease. We highlight protein translocation defects across the endoplasmic reticulum membrane, the principal role of the SEC61 complex, as a contributory pathogenic mechanism for ADTKD.
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http://dx.doi.org/10.1016/j.ajhg.2016.05.028DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5005467PMC
July 2016