Publications by authors named "Nabila Bouatia-Naji"

68 Publications

Plasma and genetic determinants of soluble TREM-1 and major adverse cardiovascular events in a prospective cohort of acute myocardial infarction patients. Results from the FAST-MI 2010 study.

Int J Cardiol 2021 Sep 15. Epub 2021 Sep 15.

Sorbonne Université, Université Pierre et Marie Curie site St Antoine, F-75012 Paris, France; FACT (French Alliance for CV clinical Trials), F-CRIN Network, Inserm U-1148, Paris, France; Hôpitaux de Paris, Clinical Pharmacology Department, Plateforme de Recherche Clinique de L'Est Parisien (URCEST-CRCEST-CRBHUEP-SU), Hôpital Saint Antoine, Paris, France.

Introduction: Triggering receptor expressing on myeloid cells (TREM)-1 is involved in the pathophysiology of ischemic heart disease. Plasma soluble TREM-1 levels (sTREM-1) has been associated with increased risk of major adverse cardiovascular events (MACE) in acute myocardial infarction (AMI) patients. However, the causative link between TREM-1 and MACE remains unknown and requires further investigation before developing potential therapeutic approaches.

Methods And Results: Using the serum and DNA data bank from the prospective, nationwide French registry of Acute ST-elevation and non-ST-elevation Myocardial Infarction (FAST-MI 2010, N = 1293), we studied the association of plasma levels of sTREM-1 with 9 common genetic variants at the TREM1 locus and their relationship with recurrent MACE over a 3-year follow up. Plasma levels of sTREM-1 were associated with an increased risk of MACEs (death, recurrent MI or stroke) (adjusted HR = 1.86, 95%CI = 1.06-3.26 and HR = 1.11, 95%CI = 0.61-2.02 respectively for tertiles 3 and 2 versus tertile 1, P < 0.001). The study of common variants identified two major genetic determinants of sTREM-1 (rs4714449: beta = -0.11, P = 7.85 × 10 and rs3804276: beta = 0.18, P = 2.65 × 10) with a potential role on maintenance and/or differentiation of hematopoietic stem cells. However, associated variants only explained 4% of sTREM-1 variance (P = 2.74 × 10). Moreover, the rs4714449 variant, individually and in haplotype, was not significantly associated with MACE (HR = 0.61, 95%CI: 0.35-1.05, P = 0.07).

Conclusions: Despite its relationship with increased risk of death, recurrent MI and stroke, genetic determinants of plasma levels of sTREM-1 were not found to be causal prognostic factors in patients with acute myocardial infarction.
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http://dx.doi.org/10.1016/j.ijcard.2021.09.018DOI Listing
September 2021

Genome-Wide Association Meta-Analysis Supports Genes Involved in Valve and Cardiac Development to Associate With Mitral Valve Prolapse.

Circ Genom Precis Med 2021 Aug 31:CIRCGEN120003148. Epub 2021 Aug 31.

PARCC, Inserm, Université de Paris, F-75015 (M.Y., S.K., X.J., N.B.-N.).

Background: Mitral valve prolapse (MVP) is a common cardiac valve disease, which affects 1 in 40 in the general population. Previous genome-wide association study have identified 6 risk loci for MVP. But these loci explained only partially the genetic risk for MVP. We aim to identify additional risk loci for MVP by adding data set from the UK Biobank.

Methods: We reanalyzed 1007/479 cases from the MVP-France study, 1469/862 controls from the MVP-Nantes study for reimputation genotypes using HRC and TOPMed panels. We also incorporated 434 MVP cases and 4527 controls from the UK Biobank for discovery analyses. Genetic association was conducted using SNPTEST and meta-analyses using METAL. We used FUMA for post-genome-wide association study annotations and MAGMA for gene-based and gene-set analyses.

Results: We found TOPMed imputation to perform better in terms of accuracy in the lower ranges of minor allele frequency below 0.1. Our updated meta-analysis included UK Biobank study for ≈8 million common single-nucleotide polymorphisms (minor allele frequency >0.01) and replicated the association on Chr2 as the top association signal near . We identified an additional risk locus on Chr1 () and 2 suggestive risk loci on chr8 () and chr19 (), all driven by common variants. Gene-based association using MAGMA revealed 6 risk genes for MVP with pronounced expression levels in cardiovascular tissues, especially the heart and globally part of enriched GO terms related to cardiac development.

Conclusions: We report an updated meta-analysis genome-wide association study for MVP using dense imputation coverage and an improved case-control sample. We describe several loci and genes with MVP spanning biological mechanisms highly relevant to MVP, especially during valve and heart development.
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http://dx.doi.org/10.1161/CIRCGEN.120.003148DOI Listing
August 2021

Chromatin Accessibility of Human Mitral Valves and Functional Assessment of MVP Risk Loci.

Circ Res 2021 03 28;128(5):e84-e101. Epub 2021 Jan 28.

Université de Paris, PARCC, Inserm, France (S.K., A.G., M.Y., T.B., P.B., N.B.-N.).

Rationale: Mitral valve prolapse (MVP) is a common valvopathy that leads to mitral insufficiency, heart failure, and sudden death. Functional genomic studies in mitral valves are needed to better characterize MVP-associated variants and target genes.

Objective: To establish the chromatin accessibility profiles and assess functionality of variants and narrow down target genes at MVP loci.

Methods And Results: We mapped the open chromatin regions in nuclei from 11 human pathogenic and 7 nonpathogenic mitral valves by an assay for transposase-accessible chromatin with high-throughput sequencing. Open chromatin peaks were globally similar between pathogenic and nonpathogenic valves. Compared with the heart tissue and cardiac fibroblasts, we found that MV-specific assay for transposase-accessible chromatin with high-throughput sequencing peaks are enriched near genes involved in extracellular matrix organization, chondrocyte differentiation, and connective tissue development. One of the most enriched motifs in MV-specific open chromatin peaks was for the nuclear factor of activated T cells family of TFs (transcription factors) involved in valve endocardial and interstitial cell formation. We also found that MVP-associated variants were significantly enriched (<0.05) in mitral valve open chromatin peaks. Integration of the assay for transposase-accessible chromatin with high-throughput sequencing data with risk loci, extensive functional annotation, and gene reporter assay suggest plausible causal variants for rs2641440 at the locus and rs6723013 at the locus. CRISPR-Cas9 deletion of the sequence including rs6723013 in human fibroblasts correlated with increased expression only for . Circular chromatin conformation capture followed by high-throughput sequencing experiments provided evidence for several target genes, including , , and at the locus and further supported as the most likely target gene on chromosome 2.

Conclusions: Here, we describe unprecedented genome-wide open chromatin profiles from human pathogenic and nonpathogenic MVs and report specific gene regulation profiles, compared with the heart. We also report in vitro functional evidence for potential causal variants and target genes at MVP risk loci involving established and new biological mechanisms. Graphic Abstract: A graphic abstract is available for this article.
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http://dx.doi.org/10.1161/CIRCRESAHA.120.317581DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8316483PMC
March 2021

Sex-dimorphic genetic effects and novel loci for fasting glucose and insulin variability.

Nat Commun 2021 01 5;12(1):24. Epub 2021 Jan 5.

Department of Biostatistics and Data Science, Division of Public Health Sciences, Wake Forest University School of Medicine, Winston-Salem, NC, USA.

Differences between sexes contribute to variation in the levels of fasting glucose and insulin. Epidemiological studies established a higher prevalence of impaired fasting glucose in men and impaired glucose tolerance in women, however, the genetic component underlying this phenomenon is not established. We assess sex-dimorphic (73,089/50,404 women and 67,506/47,806 men) and sex-combined (151,188/105,056 individuals) fasting glucose/fasting insulin genetic effects via genome-wide association study meta-analyses in individuals of European descent without diabetes. Here we report sex dimorphism in allelic effects on fasting insulin at IRS1 and ZNF12 loci, the latter showing higher RNA expression in whole blood in women compared to men. We also observe sex-homogeneous effects on fasting glucose at seven novel loci. Fasting insulin in women shows stronger genetic correlations than in men with waist-to-hip ratio and anorexia nervosa. Furthermore, waist-to-hip ratio is causally related to insulin resistance in women, but not in men. These results position dissection of metabolic and glycemic health sex dimorphism as a steppingstone for understanding differences in genetic effects between women and men in related phenotypes.
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http://dx.doi.org/10.1038/s41467-020-19366-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7785747PMC
January 2021

National French registry of spontaneous coronary artery dissections: prevalence of fibromuscular dysplasia and genetic analyses.

EuroIntervention 2021 Aug;17(6):508-515

Department of Cardiology, CHU Clermont-Ferrand, CNRS, Université Clermont Auvergne, Clermont-Ferrand, France.

Background: Spontaneous coronary artery dissection (SCAD) is an increasingly reported but poorly understood condition. Few European data are available.

Aims: The aims of this study were to obtain European data on SCAD, determine the prevalence of fibromuscular dysplasia (FMD) and enable genetic analyses in this population.

Methods: Data from a national French registry of SCAD cases were analysed prospectively and retrospectively. Clinical and angiographic data and management strategy were collected. Major adverse cardiovascular events (MACE) were analysed after one year of follow-up. Subjects were screened for FMD and blood was collected for DNA extraction.

Results: From June 2016 to August 2018, 373 SCAD cases were confirmed by the core lab. Mean age was 51.5 years. Patients were mostly women (90.6%) and 54.7% of cases had less than two cardiovascular risk factors. At one year, 295 patients (79.1%) were treated conservatively, the MACE rate was 12.3%, and there were no cases of mortality. The recurrence rate of SCAD was 3.3%. FMD was found at ≥1 arterial site in 45.0% of cases. We also confirmed the genetic association between the PHACTR1 locus and SCAD (odds ratio=1.66, p=7.08×10-8).

Conclusions: Here we describe the DISCO registry, the largest European SCAD cohort where FMD was found in 45% of cases and the genetic association with PHACTR1 was confirmed. This nationwide cohort is a valuable resource for future clinical and genetic investigation to understand SCAD aetiology.
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http://dx.doi.org/10.4244/EIJ-D-20-01046DOI Listing
August 2021

Spontaneous Coronary Artery Dissection: Insights on Rare Genetic Variation From Genome Sequencing.

Circ Genom Precis Med 2020 12 30;13(6):e003030. Epub 2020 Oct 30.

Department of Cardiovascular Sciences and NIHR Leicester Biomedical Research Centre, University of Leicester, United Kingdom (A.A.B., T.R.W., S.E.H., D.P., A.A.-H., A.W., D.K., N.J.S., D.A.).

Background: Spontaneous coronary artery dissection (SCAD) occurs when an epicardial coronary artery is narrowed or occluded by an intramural hematoma. SCAD mainly affects women and is associated with pregnancy and systemic arteriopathies, particularly fibromuscular dysplasia. Variants in several genes, such as those causing connective tissue disorders, have been implicated; however, the genetic architecture is poorly understood. Here, we aim to better understand the diagnostic yield of rare variant genetic testing among a cohort of SCAD survivors and to identify genes or gene sets that have a significant enrichment of rare variants.

Methods: We sequenced a cohort of 384 SCAD survivors from the United Kingdom, alongside 13 722 UK Biobank controls and a validation cohort of 92 SCAD survivors. We performed a research diagnostic screen for pathogenic variants and exome-wide and gene-set rare variant collapsing analyses.

Results: The majority of patients within both cohorts are female, 29% of the study cohort and 14% validation cohort have a remote arteriopathy. Four cases across the 2 cohorts had a diagnosed connective tissue disorder. We identified pathogenic or likely pathogenic variants in 7 genes (, , , , , , and ) in 14/384 cases in the study cohort and in 1/92 cases in the validation cohort. In our rare variant collapsing analysis, was the highest-ranked gene, and several functionally plausible genes were enriched for rare variants, although no gene achieved study-wide statistical significance. Gene-set enrichment analysis suggested a role for additional genes involved in renal function.

Conclusions: By studying the largest sequenced cohort of SCAD survivors, we demonstrate that, based on current knowledge, only a small proportion have a pathogenic variant that could explain their disease. Our findings strengthen the overlap between SCAD and renal and connective tissue disorders, and we highlight several new genes for future validation.
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http://dx.doi.org/10.1161/CIRCGEN.120.003030DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7748045PMC
December 2020

Rare loss-of-function mutations of PTGIR are enriched in fibromuscular dysplasia.

Cardiovasc Res 2021 03;117(4):1154-1165

Department of Radiology, Assistance-publique-hôpitaux de Paris, Hopital Européen Georges Pompidou, F-75015 Paris, France.

Aims: Fibromuscular dysplasia (FMD) and spontaneous coronary artery dissection (SCAD) are related, non-atherosclerotic arterial diseases mainly affecting middle-aged women. Little is known about their physiopathological mechanisms. We aimed to identify rare genetic causes to elucidate molecular mechanisms implicated in FMD and SCAD.

Methods And Results: We analysed 29 exomes that included familial and sporadic FMD. We identified one rare loss-of-function variant (LoF) (frequencygnomAD = 0.000075) shared by two FMD sisters in the prostaglandin I2 receptor gene (PTGIR), a key player in vascular remodelling. Follow-up was conducted by targeted or Sanger sequencing (1071 FMD and 363 SCAD patients) or lookups in exome (264 FMD) or genome sequences (480 SCAD), all independent and unrelated. It revealed four additional LoF allele carriers, in addition to several rare missense variants, among FMD patients, and two LoF allele carriers among SCAD patients, including one carrying a rare splicing mutation (c.768 + 1C>G). We used burden test to test for enrichment in patients compared to gnomAD controls, which detected a putative enrichment in FMD (PTRAPD = 8 × 10-4), but not a significant enrichment (PTRAPD = 0.12) in SCAD. The biological effects of variants on human prostaclycin receptor (hIP) signalling and protein expression were characterized using transient overexpression in human cells. We confirmed the LoFs (Q163X and P17RfsX6) and one missense (L67P), identified in one FMD and one SCAD patient, to severely impair hIP function in vitro.

Conclusions: Our study shows that rare genetic mutations in PTGIR are enriched among FMD patients and found in SCAD patients, suggesting a role for prostacyclin signalling in non-atherosclerotic stenosis and dissection.
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http://dx.doi.org/10.1093/cvr/cvaa161DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7983006PMC
March 2021

Transcriptome Analysis of lncRNAs in Pheochromocytomas and Paragangliomas.

J Clin Endocrinol Metab 2020 03;105(3)

Paris University, PARCC, INSERM, Equipe labellisée par la Ligue contre le cancer, Paris, France.

Context: Pheochromocytomas and paragangliomas (PPGLs) are neuroendocrine tumors explained by germline or somatic mutations in about 70% of cases. Patients with SDHB mutations are at high risk of developing metastatic disease, yet no reliable tumor biomarkers are available to predict tumor aggressiveness.

Objective: We aimed at identifying long noncoding RNAs (lncRNAs) specific for PPGL molecular groups and metastatic progression.

Design And Methods: To analyze the expression of lncRNAs, we used a mining approach of transcriptome data from a well-characterized series of 187 tumor tissues. Clustering consensus analysis was performed to determine a lncRNA-based classification, and informative transcripts were validated in an independent series of 51 PPGLs. The expression of metastasis-related lncRNAs was confirmed by RT-qPCR. Receiver operating characteristic (ROC) curve analysis was used to estimate the predictive accuracy of potential markers.

Main Outcome Measure: Univariate/multivariate and metastasis-free survival (MFS) analyses were carried out for the assessment of risk factors and clinical outcomes.

Results: Four lncRNA-based subtypes strongly correlated with mRNA expression clusters (chi-square P-values from 1.38 × 10-32 to 1.07 × 10-67). We identified one putative lncRNA (GenBank: BC063866) that accurately discriminates metastatic from benign tumors in patients with SDHx mutations (area under the curve 0.95; P = 4.59 × 10-05). Moreover, this transcript appeared as an independent risk factor associated with poor clinical outcome of SDHx carriers (log-rank test P = 2.29 × 10-05).

Conclusion: Our findings extend the spectrum of transcriptional dysregulations in PPGL to lncRNAs and provide a novel biomarker that could be useful to identify potentially metastatic tumors in patients carrying SDHx mutations.
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http://dx.doi.org/10.1210/clinem/dgz168DOI Listing
March 2020

[Genetics provides a link between cardiovascular diseases predominantly afflicting women].

Med Sci (Paris) 2019 Aug-Sep;35(8-9):605-607. Epub 2019 Sep 18.

Inserm, U970, Paris cardiovascular research center - PARCC, 56, rue Leblanc, 75737 Paris Cedex 15, France. - Université Paris Descartes, Sorbonne Paris Cité, UMR-S970, 56, rue Leblanc, 75737 Paris Cedex 15, France.

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http://dx.doi.org/10.1051/medsci/2019119DOI Listing
April 2020

A plasma proteogenomic signature for fibromuscular dysplasia.

Cardiovasc Res 2020 01;116(1):63-77

The Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1030, New York, NY 10029, USA.

Aims: Fibromuscular dysplasia (FMD) is a poorly understood disease that predominantly affects women during middle-life, with features that include stenosis, aneurysm, and dissection of medium-large arteries. Recently, plasma proteomics has emerged as an important means to understand cardiovascular diseases. Our objectives were: (i) to characterize plasma proteins and determine if any exhibit differential abundance in FMD subjects vs. matched healthy controls and (ii) to leverage these protein data to conduct systems analyses to provide biologic insights on FMD, and explore if this could be developed into a blood-based FMD test.

Methods And Results: Females with 'multifocal' FMD and matched healthy controls underwent clinical phenotyping, dermal biopsy, and blood draw. Using dual-capture proximity extension assay and nuclear magnetic resonance-spectroscopy, we evaluated plasma levels of 981 proteins and 31 lipid sub-classes, respectively. In a discovery cohort (Ncases = 90, Ncontrols = 100), we identified 105 proteins and 16 lipid sub-classes (predominantly triglycerides and fatty acids) with differential plasma abundance in FMD cases vs. controls. In an independent cohort (Ncases = 23, Ncontrols = 28), we successfully validated 37 plasma proteins and 10 lipid sub-classes with differential abundance. Among these, 5/37 proteins exhibited genetic control and Bayesian analyses identified 3 of these as potential upstream drivers of FMD. In a 3rd cohort (Ncases = 506, Ncontrols = 876) the genetic locus of one of these upstream disease drivers, CD2-associated protein (CD2AP), was independently validated as being associated with risk of having FMD (odds ratios  = 1.36; P = 0.0003). Immune-fluorescence staining identified that CD2AP is expressed by the endothelium of medium-large arteries. Finally, machine learning trained on the discovery cohort was used to develop a test for FMD. When independently applied to the validation cohort, the test showed a c-statistic of 0.73 and sensitivity of 78.3%.

Conclusion: FMD exhibits a plasma proteogenomic and lipid signature that includes potential causative disease drivers, and which holds promise for developing a blood-based test for this disease.
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http://dx.doi.org/10.1093/cvr/cvz219DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6918065PMC
January 2020

Genetic association study between T-786C NOS3 polymorphism and essential hypertension in an Algerian population of the Oran city.

Diabetes Metab Syndr 2019 Mar - Apr;13(2):1317-1320. Epub 2019 Feb 13.

INSERM, UMR970 Paris Cardiovascular Research Center (PARCC), Paris, F-75015, France; Paris-Descartes University, Sorbonne Paris Cité, Paris, 75006, France.

Background: Essential hypertension is an important risk factor for the development of cardiovascular disease. Important candidate genes such as NOS3 gene have been widely studied and reported to be associated with essential hypertension (HTN) in human populations.

Aim: We aim in this study to analyze the relationship between NOS3 -786T/C, a common genetic variant and HTN in a sample of the Algerian population of the Oran city.

Methods: A case-control study has been performed in 154 subjects including 77 hypertensives and 77 normotensives. The recruitment of these subjects was done in local Health Centers of the city of Oran, West Algeria. HTN was defined as elevated systolic blood pressure SBD≥140  mmHg and or sustained diastolic blood pressure DBP≥90  mmHg, measured using an Omron Automatic BP Monitor - M-3W machine. Consents were obtained from all participants. Polymerase chain reaction (PCR) combined with restrictive fragment length polymorphism (RFLP) was used to genotype the NOS -786T/C variant.

Results: The distribution of the allelic frequencies did not differ between cases and controls (OR = 1.48; 95%CI [0.94-2.32], P = 0.09). However, after adjustment with the age, sex, and body mass index, we observed significant association between NOS -786C allele and HTN status (OR = 2.08; 95%CI [1.18-3.66], P = 0.01).

Conclusion: Our results indicate that the C allele of the NOS3 gene is associated with increased risk of essential hypertension in this sample of the Algerian population of the Oran city. Further validation in larger samples is needed to confirm this finding.
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http://dx.doi.org/10.1016/j.dsx.2019.02.024DOI Listing
December 2019

Genome-wide Association Study of Change in Fasting Glucose over time in 13,807 non-diabetic European Ancestry Individuals.

Sci Rep 2019 07 1;9(1):9439. Epub 2019 Jul 1.

Department of Computational Biology, University of Lausanne, Lausanne, Switzerland.

Type 2 diabetes (T2D) affects the health of millions of people worldwide. The identification of genetic determinants associated with changes in glycemia over time might illuminate biological features that precede the development of T2D. Here we conducted a genome-wide association study of longitudinal fasting glucose changes in up to 13,807 non-diabetic individuals of European descent from nine cohorts. Fasting glucose change over time was defined as the slope of the line defined by multiple fasting glucose measurements obtained over up to 14 years of observation. We tested for associations of genetic variants with inverse-normal transformed fasting glucose change over time adjusting for age at baseline, sex, and principal components of genetic variation. We found no genome-wide significant association (P < 5 × 10) with fasting glucose change over time. Seven loci previously associated with T2D, fasting glucose or HbA1c were nominally (P < 0.05) associated with fasting glucose change over time. Limited power influences unambiguous interpretation, but these data suggest that genetic effects on fasting glucose change over time are likely to be small. A public version of the data provides a genomic resource to combine with future studies to evaluate shared genetic links with T2D and other metabolic risk traits.
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http://dx.doi.org/10.1038/s41598-019-45823-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6602949PMC
July 2019

Primary cilia defects causing mitral valve prolapse.

Sci Transl Med 2019 05;11(493)

Center for Genomic Medicine, Department of Neurology, Massachusetts General Hospital Research Institute, Harvard Medical School, 185 Cambridge St., Boston, MA 02114, USA.

Mitral valve prolapse (MVP) affects 1 in 40 people and is the most common indication for mitral valve surgery. MVP can cause arrhythmias, heart failure, and sudden cardiac death, and to date, the causes of this disease are poorly understood. We now demonstrate that defects in primary cilia genes and their regulated pathways can cause MVP in familial and sporadic nonsyndromic MVP cases. Our expression studies and genetic ablation experiments confirmed a role for primary cilia in regulating ECM deposition during cardiac development. Loss of primary cilia during development resulted in progressive myxomatous degeneration and profound mitral valve pathology in the adult setting. Analysis of a large family with inherited, autosomal dominant nonsyndromic MVP identified a deleterious missense mutation in a cilia gene, A mouse model harboring this variant confirmed the pathogenicity of this mutation and revealed impaired ciliogenesis during development, which progressed to adult myxomatous valve disease and functional MVP. Relevance of primary cilia in common forms of MVP was tested using pathway enrichment in a large population of patients with MVP and controls from previously generated genome-wide association studies (GWAS), which confirmed the involvement of primary cilia genes in MVP. Together, our studies establish a developmental basis for MVP through altered cilia-dependent regulation of ECM and suggest that defects in primary cilia genes can be causative to disease phenotype in some patients with MVP.
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http://dx.doi.org/10.1126/scitranslmed.aax0290DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7331025PMC
May 2019

Genome-Wide Association Study-Driven Gene-Set Analyses, Genetic, and Functional Follow-Up Suggest GLIS1 as a Susceptibility Gene for Mitral Valve Prolapse.

Circ Genom Precis Med 2019 05;12(5):e002497

INSERM, UMR970, Paris Cardiovascular Research Center, France (M.Y., A.G., S.K., A.A.H., X.J., N.B.-N.).

Background Mitral valve prolapse (MVP) is a common heart valve disease, the most frequent indication for valve repair or replacement. MVP is characterized by excess extracellular matrix secretion and cellular disorganization, which leads to bulky valves that are unable to coapt correctly during ventricular systole resulting in mitral regurgitation, and it is associated with sudden cardiac death. Here we aim to characterize globally the biological mechanisms underlying genetic susceptibility to MVP to better characterize its triggering mechanisms. Methods We applied i-GSEA4GWAS and DEPICT, two pathway enrichment tools to MVP genome-wide association studies. We followed-up the association with MVP in an independent dataset of cases and controls. This research was conducted using the UK Biobank Resource. Immunohistochemistry staining for Glis1 (GLIS family zinc finger 1) was conducted in developing heart of mice. Knockdown of Glis1 using morpholinos was performed in zebrafish animals 72 hours postfertilization. Results We show that genes at risk loci are involved in biological functions relevant to actin filament organization, cytoskeleton biology, and cardiac development. The enrichment for positive regulation of transcription, cell proliferation, and migration motivated the follow-up of GLIS1, a transcription factor from the Krüppel-like zinc finger family. In combination with previously available data, we now report a genome-wide significant association with MVP (odds ratio, 1.20; P=4.36×10), indicating that Glis1 is expressed during embryonic development predominantly in nuclei of endothelial and interstitial cells of mitral valves in mouse. We also show that Glis1 knockdown causes atrioventricular regurgitation in developing hearts in zebrafish. Conclusions Our findings define globally molecular and cellular mechanisms underlying common genetic susceptibility to MVP and implicate established and unprecedented mechanisms. Through the GLIS1 association and function, we point at regulatory functions during cardiac development as common mechanisms to mitral valve degeneration.
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http://dx.doi.org/10.1161/CIRCGEN.119.002497DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6532425PMC
May 2019

Association of the PHACTR1/EDN1 Genetic Locus With Spontaneous Coronary Artery Dissection.

J Am Coll Cardiol 2019 01;73(1):58-66

Molecular Cardiology and Biophysics Division, Victor Chang Cardiac Research Institute, Sydney, New South Wales, Australia; St. Vincent's Clinical School, University of New South Wales, Kensington, New South Wales, Australia.

Background: Spontaneous coronary artery dissection (SCAD) is an increasingly recognized cause of acute coronary syndromes (ACS) afflicting predominantly younger to middle-aged women. Observational studies have reported a high prevalence of extracoronary vascular anomalies, especially fibromuscular dysplasia (FMD) and a low prevalence of coincidental cases of atherosclerosis. PHACTR1/EDN1 is a genetic risk locus for several vascular diseases, including FMD and coronary artery disease, with the putative causal noncoding variant at the rs9349379 locus acting as a potential enhancer for the endothelin-1 (EDN1) gene.

Objectives: This study sought to test the association between the rs9349379 genotype and SCAD.

Methods: Results from case control studies from France, United Kingdom, United States, and Australia were analyzed to test the association with SCAD risk, including age at first event, pregnancy-associated SCAD (P-SCAD), and recurrent SCAD.

Results: The previously reported risk allele for FMD (rs9349379-A) was associated with a higher risk of SCAD in all studies. In a meta-analysis of 1,055 SCAD patients and 7,190 controls, the odds ratio (OR) was 1.67 (95% confidence interval [CI]: 1.50 to 1.86) per copy of rs9349379-A. In a subset of 491 SCAD patients, the OR estimate was found to be higher for the association with SCAD in patients without FMD (OR: 1.89; 95% CI: 1.53 to 2.33) than in SCAD cases with FMD (OR: 1.60; 95% CI: 1.28 to 1.99). There was no effect of genotype on age at first event, P-SCAD, or recurrence.

Conclusions: The first genetic risk factor for SCAD was identified in the largest study conducted to date for this condition. This genetic link may contribute to the clinical overlap between SCAD and FMD.
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http://dx.doi.org/10.1016/j.jacc.2018.09.085DOI Listing
January 2019

Spontaneous coronary artery dissections and fibromuscular dysplasia: Current insights on pathophysiology, sex and gender.

Int J Cardiol 2019 07 9;286:220-225. Epub 2018 Nov 9.

Department of Cardiovascular Sciences, University of Leicester and NIHR Leicester Biomedical Research Centre, Glenfield Hospital, Leicester, UK.

Spontaneous coronary artery dissections (SCADs) are increasingly recognized as an important cause of acute coronary syndromes in predominantly women below 60 years of age. SCAD patients comprise a heterogeneous group, in which it is estimated that a quarter to one third have underlying fibromuscular dysplasia (FMD). Although the mutual relationship of SCAD and FMD is complex and only partly understood, there seems to be some overlap in genetic background and interaction with endogenous sex-steroids. In this review we provide an update of our current knowledge on these intriguing emerging arteriopathies.
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http://dx.doi.org/10.1016/j.ijcard.2018.11.023DOI Listing
July 2019

Fibromuscular Dysplasia and Its Neurologic Manifestations: A Systematic Review.

JAMA Neurol 2019 02;76(2):217-226

Paris-Descartes University, Institut National de la Santé et de la Recherche Médicale UMR970, Assistance-Publique Hôpitaux de Paris, Hôpital Européen Georges Pompidou, Hypertension Unit, Paris, France.

Importance: Data on neurologic manifestations of fibromuscular dysplasia (FMD) are rare, and current knowledge remains limited.

Objectives: To present a comprehensive review of the epidemiologic characteristics, management, and prognosis of the neurologic manifestations associated with cerebrovascular FMD (ie, involving cervical or intracranial arteries) and to guide future research priorities.

Evidence Review: References were identified through searches of PubMed from inception to December 2017 using both the medical subject headings and text words. Additional sources were also identified by reviewing reference lists of relevant articles and through searches of the authors' personal files. Selected articles described at least 1 clinical or radiologic feature and/or outcome of cerebrovascular FMD. Isolated case reports could be included if they described interesting or noteworthy manifestations of FMD.

Findings: A total of 84 relevant references were identified. Diagnosis of cerebrovascular FMD is based on the appearance of alternating arterial dilatation and constriction ("string of beads") or of focal narrowing, with no sign of atherosclerotic or inflammatory lesions. Although the diagnosis is easily apparent on results of radiographic imaging, making a diagnosis can be challenging in children or individuals with atypical phenotypes, such as purely intracranial FMD and arterial diaphragm. Involvement of multiple arteries is common, and there is increased incidence of cervical artery dissection and intracranial aneurysms. A variant in the PHACTR1 gene has been associated with FMD as well as cervical artery dissection and migraine, although less than 5% of cases of FMD are familial. Headaches, mainly of the migraine type, are observed in up to 70% of patients with FMD. Cerebrovascular FMD is mostly asymptomatic, but the most frequent neurologic manifestations include transient ischemic attack and ischemic stroke, notably in the presence of associated cervical artery dissection. Other conditions associated with FMD include subarachnoid hemorrhage and, rarely, intracranial hemorrhage. Management relies on observational data and expert opinion. Antiplatelet therapy is considered reasonable to prevent thromboembolic complications. Endovascular therapy is typically restricted to cases with symptomatic stenosis despite optimal medical therapy or in those with rupture of an intracranial aneurysm.

Conclusions And Relevance: Longitudinal cohort studies of individuals of multiple ethnicities with biosampling are needed to better understand the risk factors, pathophysiological features, and outcomes of FMD. Patient advocacy groups could assist researchers in answering patient-centered questions regarding FMD.
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http://dx.doi.org/10.1001/jamaneurol.2018.2848DOI Listing
February 2019

PHACTR1 Is a Genetic Susceptibility Locus for Fibromuscular Dysplasia Supporting Its Complex Genetic Pattern of Inheritance.

PLoS Genet 2016 Oct 28;12(10):e1006367. Epub 2016 Oct 28.

INSERM, UMR970 Paris Cardiovascular Research Center (PARCC), Paris F-75015, FRANCE.

Fibromuscular dysplasia (FMD) is a nonatherosclerotic vascular disease leading to stenosis, dissection and aneurysm affecting mainly the renal and cerebrovascular arteries. FMD is often an underdiagnosed cause of hypertension and stroke, has higher prevalence in females (~80%) but its pathophysiology is unclear. We analyzed ~26K common variants (MAF>0.05) generated by exome-chip arrays in 249 FMD patients and 689 controls. We replicated 13 loci (P<10-4) in 402 cases and 2,537 controls and confirmed an association between FMD and a variant in the phosphatase and actin regulator 1 gene (PHACTR1). Three additional case control cohorts including 512 cases and 669 replicated this result and overall reached the genomic level of significance (OR = 1.39, P = 7.4×10-10, 1,154 cases and 3,895 controls). The top variant, rs9349379, is intronic to PHACTR1, a risk locus for coronary artery disease, migraine, and cervical artery dissection. The analyses of geometrical parameters of carotids from ~2,500 healthy volunteers indicate higher intima media thickness (P = 1.97×10-4) and wall to lumen ratio (P = 0.002) in rs9349379-A carriers, suggesting indices of carotid hypertrophy previously described in carotids of FMD patients. Immunohistochemistry detected PHACTR1 in endothelium and smooth muscle cells of FMD and normal human carotids. The expression of PHACTR1 by genotypes in primary human fibroblasts showed higher expression in rs9349379-A carriers (N = 86, P = 0.003). Phactr1 knockdown in zebrafish resulted in dilated vessels indicating subtle impaired vascular development. We report the first susceptibility locus for FMD and provide evidence for a complex genetic pattern of inheritance and indices of shared pathophysiology between FMD and other cardiovascular and neurovascular diseases.
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http://dx.doi.org/10.1371/journal.pgen.1006367DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5085032PMC
October 2016

The relationship between MTHFR C677T gene polymorphism and essential hypertension in a sample of an Algerian population of Oran city.

Int J Cardiol 2016 Dec 11;225:408-411. Epub 2016 Oct 11.

INSERM, UMR970 Paris Cardiovascular Research Center (PARCC), Paris F-75015, France; Paris-Descartes University, Sorbonne Paris Cité, Paris 75006, France.

Background: Many studies have investigated the role of 5,10-methylenetetrahydrofolate reductase (MTHFR) C677T gene polymorphism in essential hypertension (EH), but with conflicting results.

Aim: To determine the eventual association between 5,10-methylenetetrahydrofolate reductase (MTHFR) C677T gene polymorphism and hypertension in a sample of Algerian population from the Oran city.

Methods: A case-control study has been performed in 154 subjects including 82 hypertensives defined as subjects with elevated systolic blood pressure SBD≥140mmHg and or sustained diastolic blood pressure DBP≥90mmHg, and 72 normotensive subjects. Polymerase chain reaction (PCR) combined with restrictive fragment length polymorphism (RFLP) was used to detect the MTHFR C677T variant.

Results: We observe no significant differences between allelic and genotypic frequencies between cases and controls for C677T polymorphism (OR=1.51, 95% CI=0.89-2.56, P=0.13). Analyses adjusted for age, sex and body mass index improved the association level, though the association was still not significant (30% vs. 22%, OR=1.75, 95% CI=0.95-3.24, P=0.07).

Conclusion: This work showed that genetic polymorphism related to the MTHFR gene (C677T) is not associated with the risk of hypertension in this sample of Algerian population. Larger case-control samples are required to clearly assess the role of this genetic variant in EH.
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http://dx.doi.org/10.1016/j.ijcard.2016.10.027DOI Listing
December 2016

The MITF, p.E318K Variant, as a Risk Factor for Pheochromocytoma and Paraganglioma.

J Clin Endocrinol Metab 2016 12 28;101(12):4764-4768. Epub 2016 Sep 28.

INSERM (L.J.C.-V., S.R.K., N.K., A.B., L.A., N.B.-N., J.F., A.-P.G.-R.), UMR970, Paris-Cardiovascular Research Center, F-75015, Paris, France; Université Paris Descartes (L.J.C.-V., S.R.K., N.B., A.B., L.A., N.B.-N., J.F., A.-P.G.-R.), PRES Sorbonne Paris Cité, Faculté de Médecine, F-75006 Paris, France; Service de Génétique, Hôpital Européen Georges Pompidou, Assistance Publique-Hôpitaux de Paris (N.B., C.S., A.-P.G.-R.), F-75015, Paris, France; Unité Hypertension artérielle (L.A.), Hôpital Européen Georges Pompidou, Assistance Publique-Hôpitaux de Paris, F-75015, Paris, France; Département de Cancérologie endocrinienne and Université Paris-Saclay (A.B., M.S.), Gustave Roussy, Villejuif, F-94805, France; Université Paris 13 (P.G.), Equipe de Recherche en Epidémiologie Nutritionnelle (EREN), Centre d'Epidémiologie et Statistiques Sorbonne Paris Cité, INSERM (U1153), Inra (U1125), Cnam, COMUE Sorbonne Paris Cité, Bobigny; INSERM (B.B.-d.P.), U1186, Université Paris-Sud, Université Paris-Saclay, Villejuif, F-94805, France; Département de Biopathologie (B.B.-d.P.), Gustave Roussy, Villejuif, F-94805, France; and Rare Adrenal Cancer Network COMETE (L.A., A.-P.G.-R.), F-75006, Paris, France.

Context: The microphthalmia-associated transcription factor (MITF) regulates the survival, proliferation, and differentiation of neural crest-derived lineages. Recent studies reported an increased risk of melanoma in individuals carrying the rare variant MITF, p.E318K (rs149617956). Whether this variant plays a role in other neural crest-derived tumors is unknown.

Objective: In the present study, we aimed at determining the prevalence of the MITF, p.E318K variant, in a well-characterized French cohort of pheochromocytomas/paragangliomas (PCC/PGL).

Design And Methods: Genomic DNA from 555 unrelated patients with PCC/PGL was genotyped for the p.E318K variant in MITF using Sanger sequencing.

Main Outcome Measure: The prevalence of the mutation in the PCC/PGL cohort was compared with a population-based sample of 2348 ethnically matched controls.

Results: We identified seven carriers (five patients with sporadic PCCs, two with PGLs). The prevalence of the MITF, p.E318K variant, was higher in the PCC/PGL cohort than in controls, and appears to be a significant risk factor (odds ratio, 3.19; 95% confidence interval, 1.34-7.59; P = .005). Noteworthy, two patients were homozygous for the p.E318K risk allele, a patient with metastatic PCC and an SDHB-mutated patient with PGL.

Conclusion: Our results indicate that the germline variant MITF, p.E318K is associated with an increased risk of other neural crest-derived tumors such as PCC/PGL.
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http://dx.doi.org/10.1210/jc.2016-2103DOI Listing
December 2016

The genetics of blood pressure regulation and its target organs from association studies in 342,415 individuals.

Nat Genet 2016 10 12;48(10):1171-1184. Epub 2016 Sep 12.

Children's Hospital Oakland Research Institute, Oakland, CA 94609, USA.

To dissect the genetic architecture of blood pressure and assess effects on target organ damage, we analyzed 128,272 SNPs from targeted and genome-wide arrays in 201,529 individuals of European ancestry, and genotypes from an additional 140,886 individuals were used for validation. We identified 66 blood pressure-associated loci, of which 17 were new; 15 harbored multiple distinct association signals. The 66 index SNPs were enriched for cis-regulatory elements, particularly in vascular endothelial cells, consistent with a primary role in blood pressure control through modulation of vascular tone across multiple tissues. The 66 index SNPs combined in a risk score showed comparable effects in 64,421 individuals of non-European descent. The 66-SNP blood pressure risk score was significantly associated with target organ damage in multiple tissues but with minor effects in the kidney. Our findings expand current knowledge of blood pressure-related pathways and highlight tissues beyond the classical renal system in blood pressure regulation.
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http://dx.doi.org/10.1038/ng.3667DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5042863PMC
October 2016

Top Advances in Functional Genomics and Translational Biology for 2015.

Circ Cardiovasc Genet 2016 Apr;9(2):189-92

From the Early Career Committee of the American Heart Association, Functional Genomics and Translational Biology Council, Dallas, TX.

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http://dx.doi.org/10.1161/CIRCGENETICS.116.001421DOI Listing
April 2016

Genetic associations at 53 loci highlight cell types and biological pathways relevant for kidney function.

Nat Commun 2016 Jan 21;7:10023. Epub 2016 Jan 21.

Unit of Genetic Epidemiology and Bioinformatics, Department of Epidemiology, University Medical Center Groningen, PO Box 30001, Groningen 9700 RB, The Netherlands.

Reduced glomerular filtration rate defines chronic kidney disease and is associated with cardiovascular and all-cause mortality. We conducted a meta-analysis of genome-wide association studies for estimated glomerular filtration rate (eGFR), combining data across 133,413 individuals with replication in up to 42,166 individuals. We identify 24 new and confirm 29 previously identified loci. Of these 53 loci, 19 associate with eGFR among individuals with diabetes. Using bioinformatics, we show that identified genes at eGFR loci are enriched for expression in kidney tissues and in pathways relevant for kidney development and transmembrane transporter activity, kidney structure, and regulation of glucose metabolism. Chromatin state mapping and DNase I hypersensitivity analyses across adult tissues demonstrate preferential mapping of associated variants to regulatory regions in kidney but not extra-renal tissues. These findings suggest that genetic determinants of eGFR are mediated largely through direct effects within the kidney and highlight important cell types and biological pathways.
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http://dx.doi.org/10.1038/ncomms10023DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4735748PMC
January 2016

Genetic risk of type 2 diabetes in populations of the African continent: A systematic review and meta-analyses.

Diabetes Res Clin Pract 2016 Apr 18;114:136-50. Epub 2016 Jan 18.

Non-Communicable Diseases Research Unit, South African Medical Research Council, Cape Town, South Africa; Department of Medicine, Groote Schuur Hospital, University of Cape Town, Cape Town, South Africa; The George Institute for Global Health, The University of Sydney, Sydney, NSW, Australia. Electronic address:

Background: Type 2 diabetes (T2D) is growing faster in Africa than anywhere else, driven by the dual effects of genetic and environmental factors. We conducted a systematic review and meta-analyses of published studies on genetic markers of T2D in populations within Africa.

Methods: Multiple databases were searched for studies of genetic variants associated with T2D in populations living in Africa. Studies reporting on the association of a genetic marker with T2D or indicators of glycaemia were included. Data were extracted on study design and characteristics, genetic determinants, effect estimates of associations with T2D.

Findings: Overall, 100 polymorphisms in 57 genes have been investigated in relation with T2D in populations within Africa, in 60 studies. Almost all studies used the candidate gene approach, with >88% published during 2006-2014 and 70% (42/60) originating from Tunisia and Egypt. Polymorphisms in ACE, AGRP, eNOS, GSTP1, HSP70-2, MC4R, MTHFR, PHLPP, POL1, TCF7L2, and TNF-α gene were found to be associated with T2D, with overlapping effect on various cardiometabolic traits. The polymorphisms investigated in multiple studies mostly had consistent effects across studies, with only modest or no statistical heterogeneity. Effect sizes were modestly significant [e.g., odd ratio 1.49 (95%CI 1.33-1.66) for TCF7L2 (rs7903146)]. Underpowered genome-wide studies revealed no diabetes risk loci specific to African populations.

Interpretation: Current evidence on the genetic markers of T2D in African populations mostly originate from North African countries, is overall scanty and largely insufficient to reliably inform the genetic architecture of T2D across Africa.
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http://dx.doi.org/10.1016/j.diabres.2016.01.003DOI Listing
April 2016

Mitral valve disease--morphology and mechanisms.

Nat Rev Cardiol 2015 Dec 20;12(12):689-710. Epub 2015 Oct 20.

Aix-Marseille University, INSERM UMR 910, Marseille, France.

Mitral valve disease is a frequent cause of heart failure and death. Emerging evidence indicates that the mitral valve is not a passive structure, but--even in adult life--remains dynamic and accessible for treatment. This concept motivates efforts to reduce the clinical progression of mitral valve disease through early detection and modification of underlying mechanisms. Discoveries of genetic mutations causing mitral valve elongation and prolapse have revealed that growth factor signalling and cell migration pathways are regulated by structural molecules in ways that can be modified to limit progression from developmental defects to valve degeneration with clinical complications. Mitral valve enlargement can determine left ventricular outflow tract obstruction in hypertrophic cardiomyopathy, and might be stimulated by potentially modifiable biological valvular-ventricular interactions. Mitral valve plasticity also allows adaptive growth in response to ventricular remodelling. However, adverse cellular and mechanobiological processes create relative leaflet deficiency in the ischaemic setting, leading to mitral regurgitation with increased heart failure and mortality. Our approach, which bridges clinicians and basic scientists, enables the correlation of observed disease with cellular and molecular mechanisms, leading to the discovery of new opportunities for improving the natural history of mitral valve disease.
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http://dx.doi.org/10.1038/nrcardio.2015.161DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4804623PMC
December 2015

Genetic association analyses highlight biological pathways underlying mitral valve prolapse.

Nat Genet 2015 Oct 24;47(10):1206-11. Epub 2015 Aug 24.

Cardiovascular Research Center, Massachusetts General Hospital, Charlestown, Massachusetts, USA.

Nonsyndromic mitral valve prolapse (MVP) is a common degenerative cardiac valvulopathy of unknown etiology that predisposes to mitral regurgitation, heart failure and sudden death. Previous family and pathophysiological studies suggest a complex pattern of inheritance. We performed a meta-analysis of 2 genome-wide association studies in 1,412 MVP cases and 2,439 controls. We identified 6 loci, which we replicated in 1,422 cases and 6,779 controls, and provide functional evidence for candidate genes. We highlight LMCD1 (LIM and cysteine-rich domains 1), which encodes a transcription factor and for which morpholino knockdown of the ortholog in zebrafish resulted in atrioventricular valve regurgitation. A similar zebrafish phenotype was obtained with knockdown of the ortholog of TNS1, which encodes tensin 1, a focal adhesion protein involved in cytoskeleton organization. We also showed expression of tensin 1 during valve morphogenesis and describe enlarged posterior mitral leaflets in Tns1(-/-) mice. This study identifies the first risk loci for MVP and suggests new mechanisms involved in mitral valve regurgitation, the most common indication for mitral valve repair.
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http://dx.doi.org/10.1038/ng.3383DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4773907PMC
October 2015

Mutations in DCHS1 cause mitral valve prolapse.

Nature 2015 Sep 10;525(7567):109-13. Epub 2015 Aug 10.

National Heart and Lung Institute, Harefield, Heart Science Centre, Imperial College London, London SW7 2AZ, UK.

Mitral valve prolapse (MVP) is a common cardiac valve disease that affects nearly 1 in 40 individuals. It can manifest as mitral regurgitation and is the leading indication for mitral valve surgery. Despite a clear heritable component, the genetic aetiology leading to non-syndromic MVP has remained elusive. Four affected individuals from a large multigenerational family segregating non-syndromic MVP underwent capture sequencing of the linked interval on chromosome 11. We report a missense mutation in the DCHS1 gene, the human homologue of the Drosophila cell polarity gene dachsous (ds), that segregates with MVP in the family. Morpholino knockdown of the zebrafish homologue dachsous1b resulted in a cardiac atrioventricular canal defect that could be rescued by wild-type human DCHS1, but not by DCHS1 messenger RNA with the familial mutation. Further genetic studies identified two additional families in which a second deleterious DCHS1 mutation segregates with MVP. Both DCHS1 mutations reduce protein stability as demonstrated in zebrafish, cultured cells and, notably, in mitral valve interstitial cells (MVICs) obtained during mitral valve repair surgery of a proband. Dchs1(+/-) mice had prolapse of thickened mitral leaflets, which could be traced back to developmental errors in valve morphogenesis. DCHS1 deficiency in MVP patient MVICs, as well as in Dchs1(+/-) mouse MVICs, result in altered migration and cellular patterning, supporting these processes as aetiological underpinnings for the disease. Understanding the role of DCHS1 in mitral valve development and MVP pathogenesis holds potential for therapeutic insights for this very common disease.
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http://dx.doi.org/10.1038/nature14670DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4720389PMC
September 2015

Investigation of the Matrix Metalloproteinase-2 Gene in Patients with Non-Syndromic Mitral Valve Prolapse.

J Cardiovasc Dev Dis 2015 Jul 10;2(3):176-189. Epub 2015 Jul 10.

Paris Cardiovascular Research Center, INSERM UMR970, 56 rue Leblanc, Paris F-75015, France.

Non-syndromic mitral valve prolapse (MVP) is a common degenerative valvulopathy, predisposing to arrhythmia and sudden death. The etiology of MVP is suspected to be under genetic control, as supported by familial cases and its manifestation in genetic syndrome (e.g., Marfan syndrome). One candidate etiological mechanism is a perturbation of the extracellular matrix (ECM) remodeling of the valve. To test this hypothesis, we assessed the role of genetic variants in the matrix metalloproteinase 2 gene () known to regulate the ECM turnover by direct degradation of proteins and for which transgenic mice develop MVP. Direct sequencing of exons of in 47 unrelated patients and segregation analyses in families did not reveal any causative mutation. We studied eight common single nucleotide polymorphisms (TagSNPs), which summarize the genetic information at the locus. The association study in two case controls sets (N = 1073 and N = 1635) provided suggestive evidence for the association of rs1556888 located downstream with the risk of MVP, especially in patients with the fibroelastic defiency form. Our study does not support the contribution of rare variation in the etiology to MVP in humans, though further genetic and molecular investigation is required to confirm our current suggestive association of one common variant.
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http://dx.doi.org/10.3390/jcdd2030176DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5753144PMC
July 2015
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