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Background Patients with arrhythmogenic right ventricular cardiomyopathy are at risk for life‐threatening ventricular tachyarrhythmias, but progressive heart failure (HF) may occur in later stages of disease. This study aimed to characterize potential risk predictors and develop a model for individualized assessment of adverse HF outcomes in arrhythmogenic right ventricular cardiomyopathy. Methods and Results Longitudinal and observational cohorts with 290 patients with arrhythmogenic right ventricular cardiomyopathy from the Fuwai Hospital in Beijing, China, and 99 patients from the University Heart Center in Zurich, Switzerland, with follow‐up data were studied. The primary end point of the study was heart transplantation or death attributable to HF. The model was developed by Cox regression analysis for predicting risk and was internally validated. During 4.92±3.03 years of follow‐up, 48 patients reached the primary end point. The determinants of the risk prediction model were left ventricular ejection fraction, serum creatinine levels, moderate‐to‐severe tricuspid regurgitation, and atrial fibrillation. Implantable cardioverter‐defibrillators did not reduce the occurrence of adverse HF outcomes. Conclusions A novel risk prediction model for arrhythmogenic right ventricular cardiomyopathy has been developed using 2 large and well‐established cohorts, incorporating common clinical parameters such as left ventricular ejection fraction, serum creatinine levels, tricuspid regurgitation, and atrial fibrillation, which can identify patients who are at risk for terminal HF events, and may guide physicians to assess individualized HF risk and to optimize management strategies.

Additional file 1. Experimental procedures and materials. Table S1. Clinical characteristics of 36 patients. Table S2. Troubleshooting table. Figure S1. Images of myocytes under conditions during optimization. Figure S2. Sarcomeres of cardiomyocytes. Figure S3. RNA integrity number of cardiomyocytes. Figure S4. Cell damage of calcium re-introduction. Figure S5. Cardiomyocytes morphology post 48-hour culture.

RH maps have been repeatedly used to assist whole genome assemblies. In the most recent examples (cow, pig, sheep), the RH mapping approach took advantage of the high density SNP chips providing a large number of markers that can be efficiently genotyped on the panel. In the absence of such a resource in duck, we sequenced 100 hybrid clones of the duck RH panel enabling direct genotyping of the assembly scaffolds on the panel. The rationale is as follow: the presence/absence of a scaffold in a particular sequenced hybrid is attested by the presence/absence of reads mapping specifically to this scaffold. The detection of scaffolds exhibiting a chromosomal breakage resulting from the irradiation process revealed itself to be a critical issue of this genotyping by sequencing process. This process resulted in the construction of RH vectors for 2027 scaffolds, representing a total of about 1 Gb of sequences (95% of the current Duck genome assembly). The subsequent linkage analysis enabled the construction of RH maps and therefore to organize, ie order and orientate, the scaffolds into pseudomolecules associated to the corresponding duck chromosomes. The whole mapping process, from sequence-based genotyping to the construction of comparative maps, will be presented as well as few examples of intra-chromosomal rearrangements that have been identified by the comparison with the chicken, turkey and zebra finch genomes and subsequently confirmed by FISH.

Duck is a very important agronomic species in France, especially for fatty liver industry which presents 75% worldwide production. Moreover, duck is also a scientific model for avian influenza research as it is a natural reservoir for avian influenza viruses. The work presented here is part of the international collaboration on duck genome sequencing, includingSNP detection and mapping, EST sequencing. Our goal is to provide a genome map allowing for fine mapping QTL and identifying candidate genes involved in expression of agronomic traits. A panel composed of 90 radiation hybrids was produced by fusing irradiated duck donor cells with hamster cells. To avoid large-scale culture of the clones, PCR genotyping involving Whole Genome Amplification (WGA) and/or reduction of reaction volumes were tested and twofirst maps for duck chromosomes were made. We also used the PCR genotyping method to test for the quality of duck sequence scaffold assemblies, which had been produced by the Beijing Genome Institute (BGI, China). Finally, to cover the whole genome, we performed a low-pass sequencing (0.1X depth) of hybrids, allowing for rapid map development. These maps allow the detection of chromosomal rearrangements that have taken place between the duck and chickengenomes, which have diverged 80 million years ago.

41 ref. chap. 11; International audience