Current approach to genetic testing and genetic evaluation referrals for adults with congenital heart disease

Background

Congenital heart disease (CHD) is the most common congenital anomaly. Up to 33% have an identifiable genetic etiology. Improved medical and surgical management of CHD has translated into longer life expectancy and a rapidly growing population of adults living with CHD. The adult CHD (ACHD) population did not have access during childhood to the genetic technologies available today and therefore have not had a robust genetic evaluation that is currently recommended for infants with CHD. Given this potential benefit; the aims of this study were to determine how ACHD cardiologists offer genetics services to patients and identify the indications that influence decision-making for genetics care.

Methods

We performed a descriptive cross-sectional study of ACHD cardiologists. A study-developed questionnaire was distributed via emailed REDCap link. The recruitment email was sent to 104 potential respondents. The survey was open from 06/2022 to 01/2023.

Results

Thirty-five cardiologists participated in the study (response rate of 34%). Most cardiologists identified as white (77%) and male (66%). Cardiologists were more likely to refer patients to genetics (91%) than to order testing themselves (57%). Of the testing ordered, chromosomal testing (55%) was ordered more than gene sequencing (14%). Most cardiologists would refer a patient with a conotruncal lesion (interrupted aortic arch) over other indications for a genetics evaluation. There were more reported barriers to ordering genetic testing (66%) compared to referring to genetics for a genetics evaluation (23%). Cardiologists were more confident recognizing features suggestive of a genetic syndrome than ordering the correct test (p = 0.001). Regarding associations between clinical factors and current practices, more years in practice trended towards less referrals and testing. Evaluating a greater number of patients (p = 0.11) and greater confidence recognizing syndromic features (p = 0.12) and ordering the correct test (p = 0.09) were all associated with ordering more testing.

Conclusion

Testing for microdeletion syndromes is being offered and completed in the ACHD population, however testing for single-gene disorders associated with CHD is being under-utilized. Developing guidelines for genetic testing in adults with CHD could increase access to genetic services, impact medical management, reduce uncertainty regarding prognosis, and inform recurrence risk estimates.

The role of genetic testing in Marfan syndrome

PURPOSE OF REVIEW

This review aims to delineate the genetic basis of Marfan syndrome (MFS) and underscore the pivotal role of genetic testing in the diagnosis, differential diagnosis, genotype-phenotype correlations, and overall disease management.

RECENT FINDINGS

The identification of pathogenic or likely pathogenic variants in the FBN1 gene, associated with specific clinical features such as aortic root dilatation or ectopia lentis, is a major diagnostic criterion for MFS. Understanding genotype-phenotype correlations is useful for determining the timing of follow-up, guiding prophylactic aortic root surgery, and providing more precise information to patients and their family members during genetic counseling. Genetic testing is also relevant in distinguishing MFS from other conditions that present with heritable thoracic aortic diseases, allowing for tailored and individualized management.

SUMMARY

Genetic testing is essential in different steps of the MFS patients' clinical pathway, starting from the phase of diagnosis to management and specific treatment.

Pregnancy in Patients with the Fontan Operation

Improved survival rates for patients with a Fontan circulation has allowed more women with this complex cardiac physiology to contemplate pregnancy. However, pregnancy in women with a Fontan circulation is associated with a high risk of adverse maternal and fetal outcomes, high rates of miscarriage and preterm delivery. Factors associated with a successful pregnancy outcome are: younger age, normal body weight, absence of significant functional limitation, no Fontan-related complications, and well-functioning single ventricle physiology. Appropriate care with timely preconception counselling and regular, frequent clinical reviews by a multidisciplinary team based at a tertiary centre, improves the chance of a successful pregnancy. Empowerment of patients with education on their specific congenital cardiac condition and its projected trajectory, helps them make informed choices regarding their health, reproductive choices and assists them to achieve their life goals.

Clinical Decision Analysis of Genetic Evaluation and Testing in 1013 Intensive Care Unit Infants with Congenital Heart Defects Supports Universal Genetic Testing

Extracardiac anomalies (ECAs) are strong predictors of genetic disorders in infants with congenital heart disease (CHD), but there are no prior studies assessing performance of ECA status as a screen for genetic diagnoses in CHD patients. This retrospective cohort study assessed this in our comprehensive inpatient CHD genetics service focusing on neonates and infants admitted to the intensive care unit (ICU). The performance and diagnostic utility of using ECA status to screen for genetic disorders was assessed using decision curve analysis, a statistical tool to assess clinical utility, determining the threshold of phenotypic screening by ECA versus a Test-All approach. Over 24% of infants had genetic diagnoses identified (n = 244/1013), and ECA-positive status indicated a 4-fold increased risk of having a genetic disorder. However, ECA status had low-moderate screening performance based on predictive summary index, a compositive measure of positive and negative predictive values. For those with genetic diagnoses, nearly one-third (32%, 78/244) were ECA-negative but had cytogenetic and/or monogenic disorders identified by genetic testing. Thus, if the presence of multiple congenital anomalies is the phenotypic driver to initiate genetic testing, 13.4% (78/580) of infants with isolated CHD with identifiable genetic causes will be missed. Given the prevalence of genetic disorders and limited screening performance of ECA status, this analysis supports genetic testing in all CHD infants in intensive care settings rather than screening based on ECA.

Research Gaps in Pediatric Heart Failure: Defining the Gaps and Then Closing Them Over the Next Decade

Given the numerous opportunities and the wide knowledge gaps in pediatric heart failure, an international group of pediatric heart failure experts with diverse backgrounds were invited and tasked with identifying research gaps in each pediatric heart failure domain that scientists and funding agencies need to focus on over the next decade.

Human Genetics of Congenital Heart Defects

Congenital heart diseases (or congenital heart defects/disorders; CHDs) are structural abnormalities of the heart and/or great vessels that are present at birth. CHDs include an extensive range of defects that may be minor and require no intervention or may be life-limiting and require complex surgery shortly after birth. This chapter reviews the current knowledge on the genetic causes of CHD.

Genetic syndromes associated with congenital heart disease

Congenital heart defects are the most common type of birth defect, affecting 1% of live births. The underlying cause of congenital heart disease is frequently unknown. However, advances in human genetics and genome technologies have helped expand congenital heart disease pathogenesis knowledge during the last few decades. When the cardiac defects are part of a genetic syndrome, they are associated with extracardiac conditions and require multidisciplinary care and surveillance. Some genetic syndromes can have subtle clinical findings and remain undiagnosed well into adulthood. Each syndrome is associated with specific congenital and acquired comorbidities and a particular clinical risk profile. A timely diagnosis is essential for risk stratification, surveillance of associated conditions and counselling, particularly during family planning. However, genetic testing and counselling indications can be challenging to identify in clinical practice. This document intends to provide an overview of the most clinically relevant syndromes to consider, focusing on the phenotype and genotype diagnosis, outcome data, clinical guidelines and implications for care.

Deep learning-derived 12-lead electrocardiogram-based genotype prediction for hypertrophic cardiomyopathy: a pilot study

Objective: Given the psychosocial and ethical burden, patients with hypertrophic cardiomyopathy (HCMs) could benefit from the establishment of genetic probability prior to the test. This study aimed to develop a simple tool to provide genotype prediction for HCMs.Methods: A convolutional neural network (CNN) was built with the 12-lead electrocardiogram (ECG) of 124 HCMs who underwent genetic testing (GT), externally tested by predicting the genotype on another HCMs cohort (n = 54), and compared with the conventional methods (the Mayo and Toronto score). Using a third cohort of HCMs (n = 76), the role of the network in risk stratification was explored by calculating the sudden cardiac death (SCD) risk scorers (HCM risk-SCD) across the predicted genotypes. Score-CAM was employed to provide a visual explanation of the network.Results: Overall, 80 of 178 HCMs (45%) were genotype-positive. Using the 12-lead ECG as input, the network showed an area under the curve (AUC) of 0.89 (95% CI, 0.83-0.96) on the test set, outperforming the Mayo score (0.69 [95% CI, 0.65-0.78], p < 0.001) and the Toronto score (0.69 [95% CI, 0.64-0.75], p < 0.001). The network classified the third cohort into two groups (predicted genotype-negative vs. predicted genotype-positive). Compared with the former, patients predicted genotype-positive had a significantly higher HCM risk-SCD (0.04 ± 0.03 vs. 0.03 ± 0.02, p <0.01). Visualization indicated that the prediction was heavily influenced by the limb lead.Conclusions: The network demonstrated a promising ability in genotype prediction and risk assessment in HCM.

Uncovering the Genetic Basis of Congenital Heart Disease: Recent Advancements and Implications for Clinical Management

Congenital heart disease (CHD) is the most prevalent hereditary disorder, affecting approximately 1% of all live births. A reduction in morbidity and mortality has been achieved with advancements in surgical intervention, yet challenges in managing complications, extracardiac abnormalities, and comorbidities still exist. To address these, a more comprehensive understanding of the genetic basis underlying CHD is required to establish how certain variants are associated with the clinical outcomes. This will enable clinicians to provide personalized treatments by predicting the risk and prognosis, which might improve the therapeutic results and the patient's quality of life. We review how advancements in genome sequencing are changing our understanding of the genetic basis of CHD, discuss experimental approaches to determine the significance of novel variants, and identify barriers to use this knowledge in the clinics. Next-generation sequencing technologies are unravelling the role of oligogenic inheritance, epigenetic modification, genetic mosaicism, and noncoding variants in controlling the expression of candidate CHD-associated genes. However, clinical risk prediction based on these factors remains challenging. Therefore, studies involving human-induced pluripotent stem cells and single-cell sequencing help create preclinical frameworks for determining the significance of novel genetic variants. Clinicians should be aware of the benefits and implications of the responsible use of genomics. To facilitate and accelerate the clinical integration of these novel technologies, clinicians should actively engage in the latest scientific and technical developments to provide better, more personalized management plans for patients.

Clinically Relevant Genetic Considerations for Patients With Tetralogy of Fallot

Genetic changes affect embryogenesis, cardiac and extracardiac phenotype, development, later onset conditions, and both short- and long-term outcomes and comorbidities in the increasing population of individuals with tetralogy of Fallot (TOF). In this review, we focus on current knowledge about clinically relevant genetics for patients with TOF across the lifespan. The latest findings for TOF genetics that are pertinent to day-to-day practice and lifelong management are highlighted: morbidity/mortality, cardiac/extracardiac features, including neurodevelopmental expression, and recent changes to prenatal screening and diagnostics. Genome-wide microarray is the first-line clinical genetic test for TOF across the lifespan, detecting relevant structural changes including the most common for TOF, the 22q11.2 microdeletion. Accumulating evidence illustrates opportunities for advances in understanding and care that may arise from genetic diagnosis at any age. We also glimpse into the near future when the multigenic nature of TOF will be more fully revealed, further enhancing possibilities for preventive care. Precision medicine is nigh.

Nono deficiency impedes the proliferation and adhesion of H9c2 cardiomyocytes through Pi3k/Akt signaling pathway

Congenital heart disease (CHD) is the most common type of birth defect and the main noninfectious cause of death during the neonatal stage. The non-POU domain containing, octamer-binding gene, NONO, performs a variety of roles involved in DNA repair, RNA synthesis, transcriptional and post-transcriptional regulation. Currently, hemizygous loss-of-function mutation of NONO have been described as the genetic origin of CHD. However, essential effects of NONO during cardiac development have not been fully elucidated. In this study, we aim to understand role of Nono in cardiomyocytes during development by utilizing the CRISPR/Cas9 gene editing system to deplete Nono in the rat cardiomyocytes H9c2. Functional comparison of H9c2 control and knockout cells showed that Nono deficiency suppressed cell proliferation and adhesion. Furthermore, Nono depletion significantly affected the mitochondrial oxidative phosphorylation (OXPHOS) and glycolysis, resulting in H9c2 overall metabolic deficits. Mechanistically we demonstrated that the Nono knockout impeded the cardiomyocyte function by attenuating phosphatidyl inositol 3 kinase-serine/threonine kinase (Pi3k/Akt) signaling via the assay for transposase-accessible chromatin using sequencing in combination with RNA sequencing. From these results we propose a novel molecular mechanism of Nono to influence cardiomyocytes differentiation and proliferation during the development of embryonic heart. We conclude that NONO may represent an emerging possible biomarkers and targets for the diagnosis and treatment of human cardiac development defects.

The Role of Genetic Testing in Patients with Heritable Thoracic Aortic Diseases

Heritable thoracic aortic disease (HTAD) is a term used to define a large group of disorders characterized by the occurrence of aortic events, mainly represented by aneurysm or dissection. These events generally involve the ascending aorta, although the involvement of other districts of the aorta or peripheral vessels may occur. HTAD can be classified as non-syndromic if the disorder is limited to the aorta, and syndromic when associated with extra-aortic features. About 20-25% of patients with non-syndromic HTAD exhibit a family history of aortic disease. Thus, a careful clinical evaluation of the proband and the first-degree family members is required to differentiate familial and sporadic cases. Genetic testing is essential since it allows confirmation of the etiological diagnosis of HTAD (particularly in patients with a significant family history) and may guide family screening. In addition, genetic diagnosis significantly impacts patients' management since the different conditions significantly differ with respect to natural history and treatment strategies. The prognosis in all HTADs is determined by the progressive dilation of the aorta, potentially leading to acute aortic events, such as dissection or rupture. Moreover, the prognosis varies according to the underlying genetic mutations. This review aims to describe the clinical characteristics and natural history of the most common HTADs, with particular emphasis on the role of genetic testing in risk stratification and management.

Genetic abnormalities in fetal congenital heart disease with aberrant right subclavian artery

Fetal aberrant right subclavian artery (ARSA) is a relatively common sonographic finding. Congenital heart disease (CHD) is the most common structural abnormality in patients with ARSA. We aimed to assess the prevalence of genetic abnormalities, particularly sequence variants, in fetuses with CHD and ARSA. By clinical phenotyping and genomic sequencing, we retrospectively reviewed all fetuses with a prenatal diagnosis of CHD combined with ARSA at a single center. As a result, we identified 30 fetuses with ARSA combined with CHD, with conotruncal anomalies being the most common (n = 12, 40%), followed by left ventricular outflow tract obstruction (n = 6, 20%) and atrioventricular septal defects (n = 6, 20%). Overall, 18 (60%) cases had a genetic diagnosis. Copy number variation sequencing analysis identified six (20%) fetuses with aneuploidy and seven (23%) with pathogenic copy-number variants. Whole-exome sequencing (WES) analysis of the remaining 17 cases revealed diagnostic genetic variants in five (29%) cases, indicating that the diagnostic yield of WES for the entire cohort was 17% (5/30). Our findings reveal the high burden of genetic abnormalities in fetal CHD with ARSA. Single-gene disorders contribute substantially to the genetic etiology of fetal CHD with ARSA.

Clinical features and complications of Loeys-Dietz syndrome: A systematic review

INTRODUCTION

Loeys-Dietz syndrome (LDS) is a connective tissue disorder that arises from mutations altering the transforming growth factor β signalling pathway. Due to the recent discovery of the underlying genetic mutations leading to LDS, the spectrum of characteristics and complications is not fully understood.

METHODS

Our search included five databases (Pubmed, SCOPUS, Web of Science, EMBASE and google scholar) and included variations of "Loeys-Dietz Syndrome" as search terms, using all available data until February 2021. All study types were included. Three reviewers screened 1394 abstracts, of which 418 underwent full-text review and 392 were included in the final analysis.

RESULTS

We identified 3896 reported cases of LDS with the most commonly reported features and complications being: aortic aneurysms and dissections, arterial tortuosity, high arched palate, abnormal uvula and hypertelorism. LDS Types 1 and 2 share many clinical features, LDS Type 2 appears to have a more aggressive aortic disease. LDS Type 3 demonstrated an increased prevalence of mitral valve prolapse and arthritis. LDS Type 4 and 5 demonstrated a lower prevalence of musculoskeletal and cardiovascular involvement. Amongst 222 women who underwent 522 pregnancies, 4% experienced an aortic dissection and the peripartum mortality rate was 1%.

CONCLUSION

We observed that LDS is a multisystem connective tissue disorder that is associated with a high burden of complications, requiring a multidisciplinary approach. Ongoing attempts to better characterise these features will allow clinicians to appropriately screen and manage these complications.

WDR62 variants contribute to congenital heart disease by inhibiting cardiomyocyte proliferation

Background

Congenital heart disease (CHD) is the most common birth defect and has high heritability. Although some susceptibility genes have been identified, the genetic basis underlying the majority of CHD cases is still undefined.

Methods

A total of 1320 unrelated CHD patients were enrolled in our study. Exome‐wide association analysis between 37 tetralogy of Fallot (TOF) patients and 208 Han Chinese controls from the 1000 Genomes Project was performed to identify the novel candidate gene WD repeat‐containing protein 62 (WDR62). WDR62 variants were searched in another expanded set of 200 TOF patients by Sanger sequencing. Rescue experiments in zebrafish were conducted to observe the effects of WDR62 variants. The roles of WDR62 in heart development were examined in mouse models with Wdr62 deficiency. WDR62 variants were investigated in an additional 1083 CHD patients with similar heart phenotypes to knockout mice by multiplex PCR‐targeting sequencing. The cellular phenotypes of WDR62 deficiency and variants were tested in cardiomyocytes, and the molecular mechanisms were preliminarily explored by RNA‐seq and co‐immunoprecipitation.

Results

Seven WDR62 coding variants were identified in the 237 TOF patients and all were indicated to be loss of function variants. A total of 25 coding and 22 non‐coding WDR62 variants were identified in 80 (6%) of the 1320 CHD cases sequenced, with a higher proportion of WDR62 variation (8%) found in the ventricular septal defect (VSD) cohort. WDR62 deficiency resulted in a series of heart defects affecting the outflow tract and right ventricle in mouse models, including VSD as the major abnormality. Cell cycle arrest and an increased number of cells with multipolar spindles that inhibited proliferation were observed in cardiomyocytes with variants or knockdown of WDR62. WDR62 deficiency weakened the association between WDR62 and the cell cycle‐regulated kinase AURKA on spindle poles, reduced the phosphorylation of AURKA, and decreased expression of target genes related to cell cycle and spindle assembly shared by WDR62 and AURKA.

Conclusions

WDR62 was identified as a novel susceptibility gene for CHD with high variant frequency. WDR62 was shown to participate in the cardiac development by affecting spindle assembly and cell cycle pathway in cardiomyocytes.

Comparison of Outcome in Patients With Familial Versus Spontaneous Atrial Septal Defect

Patients with atrial septal defects (ASDs) have increased mortality and morbidity. This can only partly be explained by hemodynamic changes caused by the ASD, suggesting additional underlying causes. Patients with an ASD have an increased burden of pathogenic gene variants in ASD-related genes, indicating genetics as an important factor in etiology. Inheritance of genetic variants with high impact can cause ASD in relatives (familial ASD). This study aimed to investigate whether lifelong outcomes were different in patients with familial ASD compared with patients with sporadic ASD. We used health registries and a nationwide cohort of 2,151 patients with ASD to compare the incidences of atrial fibrillation or flutter (together abbreviated as AF), heart failure, and mortality between patients with familial and sporadic ASD using Cox proportional hazard ratio and Fine and Gray analysis. Patients with familial ASD experienced AF and heart failure earlier in life than patients with sporadic ASD, with hazard ratios of 1.6 and 1.7, respectively. Subdistribution hazard ratios showed an increased risk of AF and heart failure in patients with familial ASD compared with patients with sporadic ASDs (2.3 and 3.1, respectively). Our results suggest that genetic variants with high impact may influence the outcomes of patients with ASD. In conclusion, patients with familial ASD have an increased risk and an earlier onset of AF and heart failure compared with patients with sporadic ASD, hence clinical awareness of arrhythmias and heart failure in patients with familial ASD may lead to timely treatment.

Thoracic Aortic Dilation: Implications for Physical Activity and Sport Participation

Thoracic aortic dilatation is a progressive condition that results from aging and many pathological conditions (i.e., connective tissue, inflammatory, shear stress disorders, severe valvular heart disease) that induce degenerative changes in the elastic properties, leading to the loss of elasticity and compliance of the aortic wall. Mild aortic root enlargement may be also observed in athletes and is considered as a normal adaptation to regular exercise training. On the other hand, high-intensity physical activity in individuals with a particular genetic substrate, such as those carrying gene variants associated with Marfan syndrome or other inherited aortopathies, can favor an excessive aortic enlargement and trigger an acute aortic dissection. The evaluation of the aortic valve and aortic root diameters, as well as the detection of a disease-causing mutation for inherited aortic disease, should be followed by a tailored decision about sport eligibility. In addition, the risk of aortic complications associated with sport in patients with genetic aortic disease is poorly characterized and is often difficult to stratify for each individual athlete. This review aims to describe the relationship between regular physical activity and aortic dilation, focusing on patients with bicuspid aortic valve and inherited aortic disease, and discuss the implications in terms of aortic disease progression and sport participation.

Genetics of Heritable Thoracic Aortic Disease

Genetic testing plays an increasing diagnostic and prognostic role in the management of patients with heritable thoracic aortic disease (HTAD). The identification of a specific variant can establish or confirm the diagnosis of syndromic HTAD, dictate extensive evaluation of the arterial tree in HTAD with known distal vasculature involvement and justify closer follow-up and earlier surgical intervention in HTAD with high risk of dissection of minimal or normal aortic size. Evolving phenotype–genotype correlations lead us towards more precise and individualized management and treatment of patients with HTAD. In this review, we present the latest evidence regarding the role of genetics in patients with HTAD.

Current state and future directions of genomic medicine in aortic dissection: A path to prevention and personalized care

Aortic dissection confers high mortality and morbidity rates despite advances in treatment, impacts quality of life, and contributes immense burden to the healthcare system globally. Efforts to prevent aortic dissection through screening and management of modifiable risk factors and early detection of aneurysms should incorporate genomic information, as it is integral to stratifying risk. However, effective integration of genomic-guided risk assessment into clinical practice will require addressing implementation barriers that currently permeate our healthcare systems. The Aortic Dissection Collaborative was established to define aortic dissection research priorities through patient engagement. Using a collaborative patient-centered feedback model, our Genomic Medicine Working Group identified related research priorities that could be investigated by pragmatic interventional studies aimed at aortic dissection prevention, utilization of genomic information to improve patient outcomes, and access to genomic medicine services. Further research is also needed to identify the genomic, lifestyle, and environmental risk factors that contribute to aortic dissection so these data can be incorporated into future comparative effectiveness studies to prevent aortic dissection.

Assessing genetic counselors' graduate school education and training in congenital heart defects

Genetic counselors are one of the many providers involved in caring for patients with congenital heart defects (CHDs); however, little is known about the cardiovascular genetics training they receive by their graduate programs. To explore the recalled education experiences regarding CHDs by practicing genetic counselors, we surveyed graduates of programs primarily accredited by the American Council on Genetic Counseling (ACGC) about their graduate training in this area, the depth of CHD-specific education they received, and whether CHDs are a substantial referral indication in their current practice. Genetic counselors were recruited from the National Society of Genetic Counselors and Twitter (n = 112), and participants reflecting multiple specialties and 35 graduate programs completed an online survey which included questions about fieldwork placements and lectures in cardiovascular genetics, exposure to classification schemes regarding cardiac embryology, and education in counseling strategies for CHDs and CHD-related topics during their graduate training. When asked whether CHDs are a substantial referral indication seen in their current practice, 55% (62/112) responded yes. Most participants (79%, 88/112) recalled receiving some education about CHDs, but 91% (80/88) reported receiving little to no education regarding embryologic classification of CHDs and how to apply classification schemes to their counseling. Both participating prenatal and pediatric GCs reported that CHDs can be a common referral indication, yet they reported receiving limited education on teratogens associated with CHDs, family screening recommendations, and recurrence risk counseling for CHDs. Based on participant responses, the majority of respondents reported receiving sufficient education on syndromes with CHDs which can be beneficial in specialties such as pediatrics. This exploratory study provides insight into opportunities to further support genetic counseling educational opportunities for CHDs. These findings suggest genetic counseling graduate programs could consider implementing education on CHD counseling strategies as a standardized component of the curriculum and that practicing genetic counselors could benefit from educational opportunities and resources with updated information on this topic.

Genetic counseling for congenital heart disease - Practice resource of the national society of genetic counselors

Congenital heart disease (CHD) is an indication which spans multiple specialties across various genetic counseling practices. This practice resource aims to provide guidance on key considerations when approaching counseling for this particular indication while recognizing the rapidly changing landscape of knowledge within this domain. This resource was developed with consensus from a diverse group of certified genetic counselors utilizing literature relevant for CHD genetic counseling practice and is aimed at supporting genetic counselors who encounter this indication in their practice both pre- and postnatally.

A new era of genetic testing in congenital heart disease: A review

Genetic and genomic testing in pediatric CHD is becoming increasingly routine, and can have important psychosocial, clinical and reproductive implications. In this paper we highlight important challenges and considerations when providing genetics consults and testing in pediatric CHD and illustrate the role of a dedicated CHD genetics clinic. Key lessons include that a) a genetic diagnosis can have clinical utility that justifies testing early in life, b) adequate genetic counselling is crucial to ensure families are supported, understand the range of possible results, and are prepared for new or unexpected health information, and c) further integration of the clinical genetics and cardiology workflows will be required to effectively manage the burgeoning information arising from genetic testing. Our experience demonstrates that a dedicated CHD genetics clinic is a valuable addition to a multidisciplinary team providing care to children with CHD.

The Implementation Science for Genomic Health Translation (INSIGHT) Study in Epilepsy: Protocol for a Learning Health Care System

BACKGROUND

Genomic medicine is poised to improve care for common complex diseases such as epilepsy, but additional clinical informatics and implementation science research is needed for it to become a part of the standard of care. Epilepsy is an exemplary complex neurological disorder for which DNA diagnostics have shown to be advantageous for patient care.

OBJECTIVE

We designed the Implementation Science for Genomic Health Translation (INSIGHT) study to leverage the fact that both the clinic and testing laboratory control the development and customization of their respective electronic health records and clinical reporting platforms. Through INSIGHT, we can rapidly prototype and benchmark novel approaches to incorporating clinical genomics into patient care. Of particular interest are clinical decision support tools that take advantage of domain knowledge from clinical genomics and can be rapidly adjusted based on feedback from clinicians.

METHODS

Building on previously developed evidence and infrastructure components, our model includes the following: establishment of an intervention-ready genomic knowledge base for patient care, creation of a health informatics platform and linking it to a clinical genomics reporting system, and scaling and evaluation of INSIGHT following established implementation science principles.

RESULTS

INSIGHT was approved by the Institutional Review Board at the University of Texas Health Science Center at Houston on May 15, 2020, and is designed as a 2-year proof-of-concept study beginning in December 2021. By design, 120 patients from the Texas Comprehensive Epilepsy Program are to be enrolled to test the INSIGHT workflow. Initial results are expected in the first half of 2023.

CONCLUSIONS

INSIGHT's domain-specific, practical but generalizable approach may help catalyze a pathway to accelerate translation of genomic knowledge into impactful interventions in patient care.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/25576.

Pregnancy in Women with Adult Congenital Heart Disease

Women with congenital heart disease are pursuing pregnancy in increasing numbers. Counseling about genetic transmission, medication management, maternal and fetal risks, and maternal longevity should be initiated well before pregnancy is considered. Although preconception medical and surgical optimization as well as coordinated multidisciplinary care throughout pregnancy decrease maternal and fetal risks, the rate of complications remains increased compared with the general population. Lesion-specific risk stratification and care throughout pregnancy further improve outcomes and decrease unnecessary interventions.

Genetic considerations for adults with congenital heart disease

Congenital heart disease (CHD) remains the most common birth defect, with an estimated incidence of approximately 1% of all births. The population of adults with CHD is growing rapidly with advances in medical care. Overall survival to adulthood in the current era estimated to exceed 90%. Genetic causes of CHD can be classified into several broad categories: (a) chromosomal aneuploidy, (b) large chromosomal deletion or duplication, (c) single gene mutation, and (d) copy number variation. However, only 20-30% of CHD cases have an established etiology characterized by either genetic abnormalities or environmental factors. The role of genetics in the field of adult CHD is only increasing. More adult patients with CHD are seeking genetic counseling to understand the etiology of their underlying CHD and the risks to future offspring. A multidisciplinary approach is essential to provide appropriate counseling to patients regarding indications for genetic testing and interpretations of results. Novel advances with precision medicine may soon enable clinicians to individualize therapies for a comprehensive approach to the care of adult patients with CHD.

The Cardiac Genome Clinic: implementing genome sequencing in pediatric heart disease

Purpose

This study investigated the diagnostic utility of nontargeted genomic testing in patients with pediatric heart disease.

Methods

We analyzed genome sequencing data of 111 families with cardiac lesions for rare, disease-associated variation.

Results

In 14 families (12.6%), we identified causative variants: seven were de novo (ANKRD11, KMT2D, NR2F2, POGZ, PTPN11, PURA, SALL1) and six were inherited from parents with no or subclinical heart phenotypes (FLT4, DNAH9, MYH11, NEXMIF, NIPBL, PTPN11). Outcome of the testing was associated with the presence of extracardiac features (p = 0.02), but not a positive family history for cardiac lesions (p = 0.67). We also report novel plausible gene–disease associations for tetralogy of Fallot/pulmonary stenosis (CDC42BPA, FGD5), hypoplastic left or right heart (SMARCC1, TLN2, TRPM4, VASP), congenitally corrected transposition of the great arteries (UBXN10), and early-onset cardiomyopathy (TPCN1). The identified candidate genes have critical functions in heart development, such as angiogenesis, mechanotransduction, regulation of heart size, chromatin remodeling, or ciliogenesis.

Conclusion

This data set demonstrates the diagnostic and scientific value of genome sequencing in pediatric heart disease, anticipating its role as a first-tier diagnostic test. The genetic heterogeneity will necessitate large-scale genomic initiatives for delineating novel gene–disease associations.

The genetic workup for structural congenital heart disease

Congenital heart disease (CHD) is the most prevalent birth defect and is the result of multiple etiologies including genetic and environmental causes. This article reviews the genetic workup for structural CHD in the clinical setting, beginning with CHD epidemiology and etiology and then moving to genetic testing, clinical evaluation, and genetic counseling. An algorithm is presented as a guide to genetic test selection, and available tests are explained with their respective advantages and limitations. Finally, future advances are discussed. As this review focuses on structural heart disease, isolated cardiomyopathies, inherited primary arrhythmia syndromes and aortopathies are not discussed.