Return of Results Policies for Genomic Research: Current Practices and the Hearts in Rhythm Organization (HiRO) Approach.

Research teams developing biobanks and/or genomic databases must develop policies for the disclosure and reporting of potentially actionable genomic results to research participants. Currently, a broad range of approaches to the return of results exist, with some studies opting for nondisclosure of research results and others following clinical guidelines for the return of potentially actionable findings from sequencing. In this review, we describe current practices and highlight decisions a research team must make when designing a return of results policy, from informed consent to disclosure practices and clinical validation options. The unique challenges of returning incidental findings in cardiac genes, including reduced penetrance and the lack of clinical screening standards for phenotype-negative individuals, are discussed. Finally, the National Hearts in Rhythm Organisation (HiRO) Registry approach is described to provide a rationale for the selective return of field-specific variants to those participating in disease-specific research. Our goal is to provide researchers with a resource when developing a return of results policy tailored for their research program, based on unique factors related to study design, research team composition, and availability of clinical resources.

Missense variants in the spectrin repeat domain of DSP are associated with arrhythmogenic cardiomyopathy: A family report and systematic review.

Rare loss of function variants in DSP, which codes for the desmosomal protein desmoplakin, have been implicated in dilated and arrhythmogenic right ventricular cardiomyopathies. We present a family with arrhythmogenic cardiomyopathy associated with a novel missense variant in DSP (NM_004415.4): c.877G>A, p.(Glu293Lys). The phenotype is characterized by predominant involvement of the left ventricle with systolic dysfunction, fibrosis, and life-threatening arrhythmias. We performed a systematic review of literature collecting all cardiomyopathy cases with rare missense variants in DSP. We demonstrate that the distribution of missense variants across the protein domains in cardiomyopathy cases differs from that in gnomAD (p = .04), with a case enrichment of rare missense variants in the spectrin repeat domain (36/78 [46%] in cases vs. 449/1495 [30%] in gnomAD; p = .004). Our findings highlight the predominance of cardiac arrhythmia and left ventricular involvement in desmoplakin cardiomyopathy and pinpoint to a potential mutation hotspot in DSP thereby facilitating missense variant interpretation in the diagnostic setting.

Characterization of a Human Induced Pluripotent Stem Cell-Derived Cardiomyocyte Model for the Study of Variant Pathogenicity: Validation of a KCNJ2 Mutation.

BACKGROUND: Long-QT syndrome is a potentially fatal condition for which 30% of patients are without a genetically confirmed diagnosis. Rapid identification of causal mutations is thus a priority to avoid at-risk situations that can lead to fatal cardiac events. Massively parallel sequencing technologies are useful for the identification of sequence variants; however, electrophysiological testing of newly identified variants is crucial to demonstrate causality. Long-QT syndrome could, therefore, benefit from having a standardized platform for functional characterization of candidate variants in the physiological context of human cardiomyocytes. METHODS AND RESULTS: Using a variant in Kir2.1 (Gly52Val) revealed by whole-exome sequencing in a patient presenting with symptoms of long-QT syndrome as a proof of principle, we demonstrated that commercially available human induced pluripotent stem cell-derived cardiomyocytes are a powerful model for screening variants involved in genetic cardiac diseases. Immunohistochemistry experiments and whole-cell current recordings in human embryonic kidney cells expressing the wild-type or the mutant Kir2.1 demonstrated that Kir2.1-52V alters channel cellular trafficking and fails to form a functional channel. Using human induced pluripotent stem cell-derived cardiomyocytes, we not only confirmed these results but also further demonstrated that Kir2.1-52V is associated with a dramatic prolongation of action potential duration with evidence of arrhythmic activity, parameters which could not have been studied using human embryonic kidney cells. CONCLUSIONS: Our study confirms the pathogenicity of Kir2.1-52V in 1 patient with long-QT syndrome and also supports the use of isogenic human induced pluripotent stem cell-derived cardiomyocytes as a physiologically relevant model for the screening of variants of unknown function.

Nonsense mutations in BAG3 are associated with early-onset dilated cardiomyopathy in French Canadians.

BACKGROUND: Dilated cardiomyopathy (DCM) is a major cause of heart failure that may require heart transplantation. Approximately one third of DCM cases are familial. Next-generation DNA sequencing of large panels of candidate genes (ie, targeted sequencing) or of the whole exome can rapidly and economically identify pathogenic mutations in familial DCM. METHODS: We recruited 64 individuals from 26 DCM families followed at the Montreal Heart Institute Cardiovascular Genetic Center and sequenced the whole exome of 44 patients and 2 controls. Both affected and unaffected family members underwent genotyping for segregation analysis. RESULTS: We found 2 truncating mutations in BAG3 in 4 DCM families (15%) and confirmed segregation with disease status by linkage (log of the odds [LOD] score = 3.8). BAG3 nonsense mutations conferred a worse prognosis as evidenced by a younger age of clinical onset (37 vs 48 years for carriers and noncarriers respectively; P = 0.037). We also found truncating mutations in TTN in 5 families (19%). Finally, we identified potential pathogenic mutations for 9 DCM families in 6 candidate genes (DSP, LMNA, MYH7, MYPN, RBM20, and TNNT2). We still need to confirm several of these mutations by segregation analysis. CONCLUSIONS: Screening an extended panel of 41 candidate genes allowed us to identify probable pathogenic mutations in 69% of families with DCM in our cohort of mostly French-Canadian patients. We confirmed the prevalence of TTN nonsense mutations in DCM. Furthermore, to our knowledge, we are the first to present an association between nonsense mutations in BAG3 and early-onset DCM.

The establishment of core competencies for canadian genetic counsellors: validation of practice based competencies.

Numerous groups of health professionals have undertaken the task of defining core competencies for their profession. The goal of establishing core competencies is to have a defined standard for such professional needs as practice guidelines, training curricula, certification, continuing competency and re-entry to practice. In 2006, the Canadian Association of Genetic Counsellors (CAGC) recognized the need for uniform practice standards for the profession in Canada, given the rapid progress of genetic knowledge and technologies, the expanding practice of genetic counsellors and the increasing demand for services. We report here the process by which the CAGC Practice Based Competencies were developed and then validated via two survey cycles, the first within the CAGC membership, and the second with feedback from external stakeholders. These competencies were formally approved in 2012 and describe the integrated skills, attitudes and judgment that genetic counsellors in Canada require in order to perform the services and duties that fall within the practice of the profession responsibly, safely, effectively and ethically.

An evaluation of pharmacists' expectations towards pharmacogenomics.

BACKGROUND: Given their expertise in pharmacotherapy, pharmacists are well positioned to play a leading role in the implementation of pharmacogenomics in clinical practice. However, little is known about the opinions of pharmacists towards pharmacogenomics or their willingness to integrate this new field in their practice. METHODS: We conducted a survey of 284 pharmacists practicing in the province of Québec (Canada) to describe the opinions, expectations and concerns of pharmacists toward pharmacogenomics. RESULTS: Pharmacists were very hopeful regarding the potential role of pharmacogenomics. Moreover, more than 95% of responders would be willing to recommend pharmacogenomic testing. Nevertheless, only 7.7% of pharmacists currently felt comfortable advising patients based on pharmacogenomic test results. Accordingly, the majority of responders (96.6%) indicated that they would like to undertake continuing education related to pharmacogenomics. CONCLUSION: Pharmacists are extremely hopeful towards pharmacogenomic testing. Furthermore, a vast majority is willing to integrate these tests as part of their clinical practice. Proper education will be required if the integration of pharmacogenomics in patient care is to be optimal.