Carte, cartographie, représentations de la Terre. Un monde à la carte. Bretagne vue du ciel

1 CD-ROMExposition de vulgarisation sur la bratagne et la cartographi

La carte d'identité de l'eau ou la biographie de notre molécule préférée

1 CD-ROMExposition de vulgarisation sur l'eau, organisée par l'Espace des Sciences et le centre Armoricain de recherches en Environnemen

Estimation of some genetic parameters in potato. Consequences for selection.

International audienc

Varia

Le vingt-deuxième numéro regroupe les contributions de trois journées de séminaires en 2016 et 2017

Shared Heritability of Blood Pressure and Pulse Wave Velocity: Insights From the STANISLAS Cohort

Background: Pulse wave velocity (PWV) is a marker of arterial stiffness, which is intrinsically highly correlated with blood pressure (BP). However, the interplay of PWV and BP heritability has not been extensively studied. This study aimed to estimate the heritability of PWV and BP and determine the genetic correlation between PWV and BP. Methods: The heritability of PWV and BP was estimated in 1080 subjects from the STANISLAS (Suivi Temporaire Annuel Non-Invasif de la Santé des Lorrains Assurés Sociaux) cohort with at least one relative using a linear mixed model within one frequentist and one Bayesian framework implemented, respectively, in the Gaston and MCMCglmm R packages. Then their genetic correlations were also estimated. Results: The heritability estimations for PWV were within the same range of the heritability of systolic BP and diastolic BP (23%, 19%, and 27%, respectively). Daytime heritability of BP was higher than nighttime BP. In addition, phenotypic correlations between PWV and systolic BP/diastolic BP were, respectively, 0.34 and 0.23, whereas nonsignificant genetic correlations were 0.08 and 0.22 respectively, indicating that PWV and diastolic BP shared more polygenic codeterminants than PWV and systolic BP. Conclusions: Our results suggest that the heritability of PWV is >20% and within the same range as BP heritability. It also suggests that the link between PWV and BP goes beyond phenotypic association: PWV and BP (in particular diastolic BP) share common genetic determinants. This genetic interdependence of PWV and BP appears largely polygenic

Layer myocardial strain is the most heritable echocardiographic trait

Abstract Aims Myocardial deformation assessed by strain analysis represents a significant advancement in our assessment of cardiac mechanics. However, whether this variable is genetically heritable or whether all/most of its variability is related to environmental factors is currently unknown. We sought to determine the heritability of echocardiographically determined cardiac mechanics indices in a population setting. Methods and results A total of 1357 initially healthy subjects (women 51.6%; 48.2 ± 14.1 years) were included in this study from 20-year follow-up after the fourth visit of the longitudinal familial STANISLAS cohort (Lorraine, France). Data were acquired using state-of-the-art cardiac ultrasound equipment, using acquisition and measurement protocols recommended by the EACVI (European Association of Cardiovascular Imaging)/ASE (American Society of Echocardiography)/Industry Task Force. Layer-specific global longitudinal strain (GLS) and global circumferential strain (full-wall, subendocardial, and subepicardial) and conventional structural and functional cardiac parameters and their potential heritability were assessed using restricted maximum likelihood analysis, with genetic relatedness matrix calculated from genome-wide association data. Indices of longitudinal/circumferential myocardial function and left ventricular (LV) ejection fraction had low heritability (ranging from 10% to 20%). Diastolic and standard LV function parameters had moderate heritability (ranging from 20% to 30%) except for end-systolic and end-diastolic volumes (30% and 45%, respectively). In contrast, global longitudinal subendocardial strain (GLSEndo)/global longitudinal subepicardial strain (GLSEpi) ratio had a high level of heritability (65%). Except for GLSEndo/GLSEpi ratio, a large percentage of variance remained unexplained (&amp;gt;50%). Conclusions In our population cohort, GLSEndo/GLSEpi ratio had a high level of heritability, whereas other classical and mechanical LV function parameters did not. Given the increasing recognition of GLSEndo/GLSEpi ratio as an early/sensitive imaging biomarker of systolic dysfunction, our results suggest the possible existence of individual genetic predispositions to myocardial decline. </jats:sec

Genetics of severe hypercholesterolemia in the general population: Insights from the STANISLAS cohort

International audienceBackground: Severe hypercholesterolemia (SH) is a common condition characterized by increased levels of total and low-density lipoprotein cholesterol (LDLc). Methods: The aim of this study is to screen for prevalence of hypercholesterolemia, perform heritability estimation of circulating lipoproteins and study the association between SH cases and surrogate cardiovascular disease markers among participants of STANISLAS cohort. Gene candidate analyses were utilized to investigate the association between lipid levels, SH and polymorphisms from the three commonly reported genes (APOB, LDLR and PCSK9). Results: Participants with SH (n=102; 6.9%) were older (58 vs. 51yr), had higher total cholesterol (290 vs. 209mg/dL), LDLc (206 vs. 136mg/dL) and triglycerides (114 vs. 88 mg/dL). Despite smoking less, they had carotid plaques more frequently (21.2 vs. 9.3%), higher cIMT (676 vs. 597µm), and had more frequent family history cardiovascular disease. The circulating lipid levels have an important heritability: LDLc 51.6%, HDLc 66.6%, total cholesterol 49.8%, and triglycerides 41.4%. The SNPs located in LDLR gene present the strongest association with LDLc levels: rs55997232, rs17242395, rs1010679, and rs11668477. Conclusion: In a healthy cohort, participants with SH had premature vascular damage. LDLc had an important component of heritability and SNPs linked to the LDLR gene presented a strong association with LDLc. These findings reinforce the need for an early identification and treatment of SH subjects, which is mostly polygenic