Genetic Basis for Congenital Heart Disease: Revisited: A Scientific Statement From the American Heart Association

Clinical efficiency of simultaneous CNV-seq and whole-exome sequencing for testing fetal structural anomalies

Background

Birth defects are responsible for approximately 7% of neonatal deaths worldwide by World Health Organization in 2004. Many methods have been utilized for examining the congenital anomalies in fetuses. This study aims to investigate the efficiency of simultaneous CNV-seq and whole-exome sequencing (WES) in the diagnosis of fetal anomaly based on a large Chinese cohort.

Methods

In this cohort study, 1800 pregnant women with singleton fetus in Hubei Province were recruited from 2018 to 2020 for prenatal ultrasonic screening. Those with fetal structural anomalies were transferred to the Maternal and Child Health Hospital of Hubei Province through a referral network in Hubei, China. After multidisciplinary consultation and decision on fetal outcome, products of conception (POC) samples were obtained. Simultaneous CNV-seq and WES was conducted to identify the fetal anomalies that can compress initial DNA and turnaround time of reports.

Results

In total, 959 couples were finally eligible for the enrollment. A total of 227 trios were identified with a causative alteration (CNV or variant), among which 191 (84.14%) were de novo. Double diagnosis of pathogenic CNVs and variants have been identified in 10 fetuses. The diagnostic yield of multisystem anomalies was significantly higher than single system anomalies (32.28% vs. 22.36%, P  = 0.0183). The diagnostic rate of fetuses with consistent intra- and extra-uterine phenotypes (172/684) was significantly higher than the rate of these with inconsistent phenotypes (17/116, P  = 0.0130).

Conclusions

Simultaneous CNV-seq and WES analysis contributed to fetal anomaly diagnosis and played a vital role in elucidating complex anomalies with compound causes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-03202-9.

Genomic frontiers in congenital heart disease

The application of next-generation sequencing to study congenital heart disease (CHD) is increasingly providing new insights into the causes and mechanisms of this prevalent birth anomaly. Whole-exome sequencing analysis identifies damaging gene variants altering single or contiguous nucleotides that are assigned pathogenicity based on statistical analyses of families and cohorts with CHD, high expression in the developing heart and depletion of damaging protein-coding variants in the general population. Gene classes fulfilling these criteria are enriched in patients with CHD and extracardiac abnormalities, evidencing shared pathways in organogenesis. Developmental single-cell transcriptomic data demonstrate the expression of CHD-associated genes in particular cell lineages, and emerging insights indicate that genetic variants perturb multicellular interactions that are crucial for cardiogenesis. Whole-genome sequencing analyses extend these observations, identifying non-coding variants that influence the expression of genes associated with CHD and contribute to the estimated ~55% of unexplained cases of CHD. These approaches combined with the assessment of common and mosaic genetic variants have provided a more complete knowledge of the causes and mechanisms of CHD. Such advances provide knowledge to inform the clinical care of patients with CHD or other birth defects and deepen our understanding of the complexity of human development. In this Review, we highlight known and candidate CHD-associated human genes and discuss how the integration of advances in developmental biology research can provide new insights into the genetic contributions to CHD.

Effects of copy number variations on brain structure and risk for psychiatric illness: Large-scale studies from the ENIGMA working groups on CNVs

The Enhancing NeuroImaging Genetics through Meta-Analysis copy number variant (ENIGMA-CNV) and 22q11.2 Deletion Syndrome Working Groups (22q-ENIGMA WGs) were created to gain insight into the involvement of genetic factors in human brain development and related cognitive, psychiatric and behavioral manifestations. To that end, the ENIGMA-CNV WG has collated CNV and magnetic resonance imaging (MRI) data from ~49,000 individuals across 38 global research sites, yielding one of the largest studies to date on the effects of CNVs on brain structures in the general population. The 22q-ENIGMA WG includes 12 international research centers that assessed over 533 individuals with a confirmed 22q11.2 deletion syndrome, 40 with 22q11.2 duplications, and 333 typically developing controls, creating the largest-ever 22q11.2 CNV neuroimaging data set. In this review, we outline the ENIGMA infrastructure and procedures for multi-site analysis of CNVs and MRI data. So far, ENIGMA has identified effects of the 22q11.2, 16p11.2 distal, 15q11.2, and 1q21.1 distal CNVs on subcortical and cortical brain structures. Each CNV is associated with differences in cognitive, neurodevelopmental and neuropsychiatric traits, with characteristic patterns of brain structural abnormalities. Evidence of gene-dosage effects on distinct brain regions also emerged, providing further insight into genotype-phenotype relationships. Taken together, these results offer a more comprehensive picture of molecular mechanisms involved in typical and atypical brain development. This "genotype-first" approach also contributes to our understanding of the etiopathogenesis of brain disorders. Finally, we outline future directions to better understand effects of CNVs on brain structure and behavior.

High-Energy Enteral Nutrition in Infants After Complex Congenital Heart Surgery

BACKGROUND

Malnutrition is common in complex congenital heart disease (CCHD). The purpose of this study was to compare the safety and efficacy of early initiation of high-energy enteral nutrition (EN) with regular energy EN in infants after surgery for CCHD.

METHODS

This is a subgroup analysis of a randomized controlled trial (RCT) which was conducted in the cardiac intensive care unit (CICU) of the largest pediatric heart center in China. Eighty children with CCHD after surgery were from two groups, the intervention group (n = 40) was given high-energy EN and the control group (n = 40) was given regular energy EN. We analyzed the effects of the two interventions on outcomes such as caloric attainment rate, gastrointestinal intolerance, duration of mechanical ventilation, and anthropometry at discharge.

RESULTS

There was no difference in the daily milk intake between the two groups, but the calorie intake (50.2 vs. 33.4, P < 0.001), protein intake (1.1 vs. 0.9, P < 0.001) and caloric attainment rate were higher in the intervention group (77.5 vs. 45.0%, P = 0.003). In addition, the incidence of pneumonia (P = 0.003) and duration of mechanical ventilation (P = 0.008) were less in the intervention group, and biceps circumference and triceps skinfold thickness at hospital discharge were greater than those in the control group (P < 0.001). We have not found statistical differences in gastrointestinal intolerance, glycemic fluctuations, incidence of pressure ulcers, length of CICU stay and postoperative hospital days between the two groups.

CONCLUSIONS

Early initiation of high-energy EN may be safe and effective in infants after complex cardiac surgery. Low doses high-energy EN did not increase gastrointestinal intolerance or glycemic fluctuations and also improved post-operative nutrition by increasing caloric and protein intake without increasing fluid intake.

Transition in cardiology 2: Maternal and fetal congenital heart disease

The number of women with congenital heart disease (CHD) reaching reproductive age has been increasing. Many women with CHDs are desirous of pregnancy, but they face issues regarding preconception, antepartum, and postpartum management. On the other hand, the fetal diagnosis of CHD has improved with advances in the technique and equipment for fetal echocardiography. Recently, experiences with fetal intervention have been reported in patients with severe CHD, such as critical aortic stenosis. Nevertheless, some types of CHD are challenge to diagnose prenatally, resulting in adverse outcomes. Medical care is part of the transitional care for women and fetuses with CHD during the perinatal period. Pre-conceptional and prenatal counseling play an important role in transitional care. Sex and reproductive education need to be performed as early as possible. We herein review the current status, important issues to be resolved, and the future of maternal and fetal CHD to relevant caregivers.

Discordant Post-natal Patterns in Fetuses With Heterotaxy Syndrome: A Retrospective Single-Centre Series on Outcome After Fetal Diagnosis

OBJECTIVE

Cardiac and extra-cardiac anomalies in 46 pre-natally diagnosed cases of heterotaxy were compared to post-natal anatomical patterns in order to reveal discordant findings. Second, the outcome of these fetuses was evaluated.

METHODS

Fetuses with heterotaxy, diagnosed in a tertiary referral centre, were analysed retrospectively. Based on the foetal abdominal situs view, right atrial isomerism (RAI) and left atrial isomerism (LAI) were defined as foetal sub-types. Post-natally, discordant anatomical patterns for broncho-pulmonary branching, atrial appendage morphology, and splenic status were further clarified with CT scans. In summary, the spectrum of pre-natally and post-natally detected cardiac and extra-cardiac anomalies is systematically reviewed. Necessary surgical interventions and mid-long-term outcomes were compared between the two sub-types in surviving infants.

RESULTS

A total of 46 fetuses with heterotaxy were included; LAI was diagnosed in 29 (63%) fetuses and RAI was diagnosed in 17 (37%) fetuses. Extra-cardiac anomalies were noted in 35% of fetuses. Seven out of the 29 fetuses (24%) with LAI had atrio-ventricular block (AVB) and four of these cases presented with hydrops. Twenty nine out of the 46 participating fetuses (63%) were live births, with 62% in the LAI group and 65% in the RAI group. Five fetuses were lost to follow-up. At the age of 1 year, the overall survival of live births [estimate (95% CI)] was 67% (48; 92%) in patients with LAI and 55% (32; 94%) in patients with RAI. At the age of 5 years, the estimates were 67% (48; 92%) in the LAI group and 46% (24-87%) in the RAI group. The median survival (first quartile; third quartile) was 11.1 (0.1; 14) years for patients with LAI and 1.3 (0.09; NA) years for patients with RAI. Of 17 children who had undergone cardiac surgery, five (29%) children achieved a bi-ventricular repair and 12 (70%) children achieved a uni-ventricular palliation. Three were primarily palliated, but converted to bi-ventricular thereafter. Foetal subtype definition of heterotaxy based on the abdominal situs and post-natal thoracic imaging studies showed a discordant pattern of broncho-pulmonary branching and atrial appendage anatomy in 40% of our live-born children.

CONCLUSION

Heterotaxy is a rare and complex condition with significant morbidity and mortality related to severe cardiac and extra-cardiac associations. Accurate pre-natal diagnosis can help identify the fetuses at risk and allow for timely intervention in a multi-disciplinary setting. Further studies are warranted to shed light on the exact sub-type definition in fetuses with heterotaxy and the presence of discordant post-natal patterns.

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.

Thirty-Year Survival after Cardiac Surgery for Patients with Turner Syndrome

OBJECTIVE

To evaluate long-term survival in patients with Turner syndrome after congenital heart surgery with a focus on left heart obstructive lesions (LHOLs).

STUDY DESIGN

We queried the Pediatric Cardiac Care Consortium, a US-based registry of congenital heart surgery, for patients with Turner syndrome undergoing congenital heart surgery at <21 years of age between 1982 and 2011. Outcomes were obtained from the Pediatric Cardiac Care Consortium and from national death and transplant registries through 2019. Survival of patients with Turner syndrome and nonsyndromic patients with similar LHOL was compared by Kaplan-Meier survival curves and Cox regression adjusted for age, congenital heart disease, and era.

RESULTS

We identified 179 patients with Turner syndrome operated for LHOL: 161 with 2-ventricle lesions (coarctation n = 149, aortic stenosis n = 12) and 18 with hypoplastic left heart (HLH) variants. There were 157 with 2-ventricle LHOL and 6 with HLH survived to discharge. Among survivors to hospital discharge, the 30-year transplant-free survival was 90.4% for Turner syndrome with 2-ventricle lesions and 90.9% for nonsyndromic comparators (adjusted hazard ratio [aHR] 1.15, 95% CI 0.64-2.04). The postdischarge survival for HLH was 33% for Turner syndrome and 51% for nonsyndromic patients, with these numbers being too small for meaningful comparisons. There was a higher risk for cardiovascular disease events in patients with Turner syndrome vs male (aHR 3.72, 95% CI 1.64-8.39) and female comparators (aHR 4.55, 95% CI 1.87-11.06) excluding heart failure deaths.

CONCLUSIONS

The 30-year transplant-free survival is similar for patients with Turner syndrome and nonsyndromic comparators with operated 2-ventricle LHOL without excess congenital heart disease risk. However, patients with Turner Syndrome still face increased cardiovascular disease morbidity, stressing the importance of lifelong comorbidity surveillance in this population.

Current Trends in Genetics and Neonatal Care

BACKGROUND

Genetic and genomic health applications are rapidly changing. A clear and updated description of these applications for the neonatal population is needed to guide current nursing practice.

PURPOSE

To provide scientific evidence and guidance on the current genetic and genomic applications pertinent to neonatal care.

METHODS

A search of CINAHL and PubMed was conducted using the search terms "newborn/neonatal" and "genetics," "genomics," "newborn screening," "pharmacogenomics," "ethical," and "legal." Google searches were also conducted to synthesize professional guidelines, position statements, and current genetic practices.

FINDINGS/RESULTS

Components of the newborn genetic assessment, including details on the newborn physical examination, family history, and laboratory tests pertinent to the newborn, are reported. The history and process of newborn screening are described, in addition to the impact of advancements, such as whole exome and genome sequencing, on newborn screening. Pharmacogenomics, a genomic application that is currently utilized primarily in the research context for neonates, is described and future implications stated. Finally, the specific ethical and legal implications for these genetic and genomic applications are detailed, along with genetic/genomic resources for nurses.

IMPLICATIONS FOR PRACTICE

Providing nurses with the most up-to-date evidence on genetic and genomic applications ensures their involvement and contributions to quality neonatal care.

IMPLICATIONS FOR RESEARCH

Ongoing genetic/genomic research is needed to understand the implications of genetic/genomic applications on the neonatal population and how these new applications will change neonatal care.

Standing on the shoulders of Giants: a citation analysis of the paediatric congenital heart disease literature

OBJECTIVE

The citation history of a published article reflects its impact on the literature over time. We conducted a comprehensive bibliometric analysis to identify the most cited papers on CHD in children.

METHODS

One-hundred and ninety journals listed in Journal Citation Reports were accessed via Web of Science. Publications with 250 or more citations were identified from Science Citation Index Expanded (1900-2020), and those relating to structural CHD in children were reviewed. Articles were ranked by citation count and the 100 most cited were analysed.

RESULTS

The number of citations ranged from 2522 to 309 (median 431, IQR 356-518), with 35 published since 2000. All were written in English, most originated from the United States (74%), and were published in cardiovascular journals, with Circulation (28%) the most frequent. There were 86 original research articles, including 50 case series, 14 cohort studies, and 10 clinical trials. The most cited paper was by Hoffman JI and Kaplan S on the incidence of CHD. Thirteen authors had 4 or more publications in the top 100, all of whom had worked in Boston, Philadelphia, San Francisco, or Dallas, and the most prolific author was Newburger JW (9 articles).

CONCLUSIONS

Citation analysis provides a historical perspective on scientific progress by assessing the impact of individual articles. Our study highlights the dominant position of US-based researchers and journals in this field. Most of the highly cited articles remain case series, with few randomised controlled trials in CHD appearing in recent years.

Clinical Manifestations of 22q11.2 Deletion Syndrome

DiGeorge syndrome (DGS), also known as "22q11.2 deletion syndrome" (22q11DS) (MIM # 192430 # 188400), is a genetic disorder caused by hemizygous microdeletion of the long arm of chromosome 22. In the last decades, the introduction of fluorescence in situ hybridization assays, and in selected cases the use of multiplex ligation-dependent probe amplification, has allowed the detection of chromosomal microdeletions that could not be previously identified using standard karyotype analysis. The aim of this review is to address cardiovascular and systemic involvement in children with DGS, provide genotype-phenotype correlations, and discuss their medical management and therapeutic options.

Investigation of Genetic Alterations in Congenital Heart Diseases in Prenatal Period

The prenatal diagnosis of congenital heart disease (CHD) is important because of mortality risk. The onset of CHD varies, and depending on the malformation type, the risk of aneuploidy is changed. To identify possible genetic alterations in CHD, G-banding, chromosomal microarray or if needed DNA mutation analysis and direct sequence analysis should be planned.

In present study, to identify genetic alterations, cell culture, karyotype analysis, and single nucleotide polymorphism, array analyses were conducted on a total 950 samples. Interventional prenatal genetic examination was performed on 23 (2, 4%, 23/950) fetal CHD cases. Chromosomal abnormalities were detected in 5 out of 23 cases (21, 7%). Detected chromosomal abnormalities were 10q23.2 deletion, trisomy 18, 8p22.3-p23.2 deletion, 8q21.3-q24.3 duplication, 11q24.2q24.5 (9 Mb) deletion, and 8p22p12 (16.8 Mb) deletion. Our study highlights the importance of genetic testing in CHD.

M-DATA: A statistical approach to jointly analyzing de novo mutations for multiple traits

Recent studies have demonstrated that multiple early-onset diseases have shared risk genes, based on findings from de novo mutations (DNMs). Therefore, we may leverage information from one trait to improve statistical power to identify genes for another trait. However, there are few methods that can jointly analyze DNMs from multiple traits. In this study, we develop a framework called M-DATA (Multi-trait framework for De novo mutation Association Test with Annotations) to increase the statistical power of association analysis by integrating data from multiple correlated traits and their functional annotations. Using the number of DNMs from multiple diseases, we develop a method based on an Expectation-Maximization algorithm to both infer the degree of association between two diseases as well as to estimate the gene association probability for each disease. We apply our method to a case study of jointly analyzing data from congenital heart disease (CHD) and autism. Our method was able to identify 23 genes for CHD from joint analysis, including 12 novel genes, which is substantially more than single-trait analysis, leading to novel insights into CHD disease etiology.

Association of Maternal History of Spontaneous Abortion and Stillbirth With Risk of Congenital Heart Disease in Offspring of Women With vs Without Type 2 Diabetes

IMPORTANCE

The associations of maternal history of spontaneous abortion (SA) and stillbirth with congenital heart disease (CHD) remain elusive.

OBJECTIVE

To evaluate the associations of maternal history of pregnancy loss with CHD in offspring and the role of maternal type 2 diabetes.

DESIGN, SETTING, AND PARTICIPANTS

This population-based cohort study included singleton live offspring born between January 1, 1977, and December 31, 2016, identified through Danish national health registries. Statistical analysis was performed from October 1, 2019, through September 1, 2021.

EXPOSURES

Maternal history of SA, with frequency varying from 1 or 2 to 3 or more episodes, and maternal history of single and multiple stillbirths.

MAIN OUTCOMES AND MEASURES

Overall CHD identified by hospital diagnosis. Cox proportional hazard regression was used to estimate the hazard ratio (HR) of CHD. Diabetes was evaluated as a potential confounder and a potential effect modifier.

RESULTS

Among 1 642 534 included offspring (mean [SD] age, 14.11 [8.39] years; 843 265 male [51.35%]), 246 669 (15.02%) were born to mothers with a history of SA and 9750 (0.59%) were born to mothers with a history of stillbirth. The HRs of CHD were 1.16 (95% CI, 1.13-1.20) for offspring with a maternal history of SA and 1.49 (95% CI, 1.32-1.68) for offspring with a maternal history of stillbirth. Significant dose-response associations were observed among offspring with a maternal history of 3 or more episodes of SA (HR, 1.60; 95% CI, 1.39-1.84) and those with maternal history of multiple stillbirths (HR, 2.75; 95% CI, 1.63-4.65). If only inpatient CHD cases were included, the risk of CHD was higher than that found in the main analysis, with HRs of 1.24 (95% CI, 1.19-1.30) for maternal history of SA and 1.78 (95% CI, 1.51-2.11) for maternal history of stillbirth. The observed associations were strengthened by maternal prepregnancy type 2 diabetes (HR for maternal history of SA, 1.65 [95% CI, 1.37-1.97]; HR for maternal history of stillbirth, 1.74 [95% CI, 1.06-2.85]).

CONCLUSIONS AND RELEVANCE

These findings suggest that offspring born to mothers with a previous SA or stillbirth, especially multiple episodes, or with prepregnancy type 2 diabetes were at a higher risk of being diagnosed with CHD. These findings may help identify women at increased risk in whom detailed fetal heart assessment may be cost-effective and highlight the importance of screening for type 2 diabetes in women of reproductive age.

Impact of maternal hyperglycemia on cardiac development: Insights from animal models

Congenital heart disease (CHD) is the leading cause of birth defect-related death in infants and is a global pediatric health concern. While the genetic causes of CHD have become increasingly recognized with advances in genome sequencing technologies, the etiology for the majority of cases of CHD is unknown. The maternal environment during embryogenesis has a profound impact on cardiac development, and numerous environmental factors are associated with an elevated risk of CHD. Maternal diabetes mellitus (matDM) is associated with up to a fivefold increased risk of having an infant with CHD. The rising prevalence of diabetes mellitus has led to a growing interest in the use of experimental diabetic models to elucidate mechanisms underlying this associated risk for CHD. The purpose of this review is to provide a comprehensive summary of rodent models that are being used to investigate alterations in cardiac developmental pathways when exposed to a maternal diabetic setting and to summarize the key findings from these models. The majority of studies in the field have utilized the chemically induced model of matDM, but recent advances have also been made using diet based and genetic models. Each model provides an opportunity to investigate unique aspects of matDM and is invaluable for a comprehensive understanding of the molecular and cellular mechanisms underlying matDM-associated CHD.

Genealogy of patients with congenital heart disease in isolated populations

In isolated populations rare genetic diseases are important and relatively frequent. The objective of this study is to determine the geographical aggregates of maternal and paternal ancestors of patients with congenital heart disease (CHD) to determine whether there is an association between the different areas and types of cardiac defects. Descriptive, observational, and cross-sectional study of patients with CHD obtained consecutively in a single adult CHD unit between January 2018 and December 2019 in Gran Canaria (Canary Islands, Spain). To be included in the study, at least one of the grandparents (maternal or paternal) should be born in Gran Canaria. 258 out of 353 CHD patients met the inclusion criteria. 58% of CHD patients were male and the median age was of 28 (21-40) years old. The most frequent types of CHD were cardiac septal defects (76 patients), right side cardiac outflow tract anomalies (74 patients) and left side cardiac outflow tract anomalies (58 patients). 13% of the patients had a family history of CHD, 11% showed consanguinity and 7% had an associated polymalformative syndrome. 20% of the four ancestors were born in the same municipality and a significant association was seen between two areas of Gran Canaria, orographically related, and right-side cardiac outflow tract anomalies (P<0.001). In conclusion in patients with tetralogy of Fallot and/or pulmonary valve stenosis/atresia an ancestry's geographic aggregation was seen.

Copy number variation analysis in Chinese children with complete atrioventricular canal and single ventricle

BACKGROUND

Congenital heart disease (CHD) is one of the most common birth defects. Copy number variations (CNVs) have been proved to be important genetic factors that contribute to CHD. Here we screened genome-wide CNVs in Chinese children with complete atrioventricular canal (CAVC) and single ventricle (SV), since there were scarce researches dedicated to these two types of CHD.

METHODS

We screened CNVs in 262 sporadic CAVC cases and 259 sporadic SV cases respectively, using a customized SNP array. The detected CNVs were annotated and filtered using available databases.

RESULTS

Among 262 CAVC patients, we identified 6 potentially-causative CNVs in 43 individuals (16.41%, 43/262), including 2 syndrome-related CNVs (7q11.23 and 8q24.3 deletion). Surprisingly, 90.70% CAVC patients with detected CNVs (39/43) were found to carry duplications of 21q11.2-21q22.3, which were recognized as trisomy 21 (Down syndrome, DS). In CAVC with DS patients, the female to male ratio was 1.6:1.0 (24:15), and the rate of pulmonary hypertension (PH) was 41.03% (16/39). Additionally, 6 potentially-causative CNVs were identified in the SV patients (2.32%, 6/259), and none of them was trisomy 21. Most CNVs identified in our cohort were classified as rare (< 1%), occurring just once among CAVC or SV individuals except the 21q11.2-21q22.3 duplication (14.89%) in CAVC cohort.

CONCLUSIONS

Our study identified 12 potentially-causative CNVs in 262 CAVC and 259 SV patients, representing the largest cohort of these two CHD types in Chinese population. The results provided strong correlation between CAVC and DS, which also showed sex difference and high incidence of PH. The presence of potentially-causative CNVs suggests the etiology of complex CHD is incredibly diverse, and CHD candidate genes remain to be discovered.

Chromosome 9p terminal deletion in nine Egyptian patients and narrowing of the critical region for trigonocephaly

Background

This study aimed to delineate the clinical phenotype of patients with 9p deletions, pinpoint the chromosomal breakpoints, and identify the critical region for trigonocephaly, which is a frequent finding in 9p terminal deletion.

Methods

We investigated a cohort of nine patients with chromosome 9p terminal deletions who all displayed developmental delay, intellectual disability, hypotonia, and dysmorphic features. Of them, eight had trigonocephaly, seven had brain anomalies, seven had autistic manifestations, seven had fair hair, and six had a congenital heart defect (CHD).

Results

Karyotyping revealed 9p terminal deletion in all patients, and patients 8 and 9 had additional duplication of other chromosomal segments. We used six bacterial artificial chromosome (BAC) clones that could identify the breakpoints at 17–20 Mb from the 9p terminus. Array CGH identified the precise extent of the deletion in six patients; the deleted regions ranged from 16 to 18.8 Mb in four patients, patient 8 had an 11.58 Mb deletion and patient 9 had a 2.3 Mb deletion.

Conclusion

The gene deletion in the 9p24 region was insufficient to cause ambiguous genitalia because six of the nine patients had normal genitalia. We suggest that the critical region for trigonocephaly lies between 11,575 and 11,587 Mb from the chromosome 9p terminus. To the best of our knowledge, this is the minimal critical region reported for trigonocephaly in 9p deletion syndrome, and it warrants further delineation.

Motor Developmental Delay After Cardiac Surgery in Children With a Critical Congenital Heart Defect: A Systematic Literature Review and Meta-analysis

PURPOSE

To systematically review evidence regarding the severity and prevalence of motor development in children with a critical congenital heart defect (CCHD) without underlying genetic anomalies.

SUMMARY OF KEY POINTS

Twelve percent of all included studies reported abnormal mean motor developmental scores, and 38% reported below average motor scores. Children with single-ventricle physiology, especially those with hypoplastic left heart syndrome, had the highest severity and prevalence of motor delay, particularly at 0 to 12 months. Most included studies did not differentiate between gross and fine motor development, yet gross motor development was more affected.

RECOMMENDATIONS FOR CLINICAL PRACTICE

We recommend clinicians differentiate between the type of heart defect, fine and gross motor development, and the presence of genetic anomalies. Furthermore, increased knowledge about severity and prevalence will enable clinicians to tailor their interventions to prevent motor development delays in CCHD.

Genetic Testing for Heritable Cardiovascular Diseases in Pediatric Patients: A Scientific Statement From the American Heart Association

Genetic diseases that affect the cardiovascular system are relatively common and include cardiac channelopathies, cardiomyopathies, aortopathies, hypercholesterolemias, and structural diseases of the heart and great vessels. The rapidly expanding availability of clinical genetic testing leverages decades of research into the genetic origins of these diseases, helping inform diagnosis, clinical management, and prognosis. Although a number of guidelines and statements detail best practices for cardiovascular genetic testing, there is a paucity of pediatric-focused statements addressing the unique challenges in testing in this vulnerable population. In this scientific statement, we seek to coalesce the existing literature around the use of genetic testing for cardiovascular disease in infants, children, and adolescents.

Early high-energy feeding in infants following cardiac surgery: a randomized controlled trial

BACKGROUND

Effective nutrition programs are beneficial for nutritional recovery in infants. Few studies have focused on the effect of early high-energy feeding after open heart surgery. This study sought to assess the effects of early high-energy feeding in infants after congenital heart surgery.

METHODS

Patients at a tertiary pediatric cardiology center who underwent open heart surgery between July 2016 and July 2018 were recruited and randomly allocated to 1 of the following 2 groups: (I) the intervention group (postoperative early high-energy feeding; n=124); and (II) the control group (no intervention; n=120).The primary endpoints of average energy delivery and growth Z-scores [i.e., weight-for-height Z-score (WHZ), weight-for-age Z-score (WAZ), and height-for-age Z-score (HAZ)] were recorded preoperatively, during the intensive care unit (ICU) stay, at discharge, and at 1 and 3 months postoperatively. The secondary endpoints of malnutrition recovery, ventilator support time, infection rate, and cardiac ICU (CICU) stay were also recorded.

RESULTS

A total of 244 infants were included in the study. There were no significant differences in the baseline features between the 2 groups. The intervention group received higher calories on average than the control group (44.5 vs. 34.7; P<0.001). At discharge from the ICU, the WHZ (-2.29 vs. -2.76; P<0.001) and WAZ (-3.08 vs. -3.43; P=0.005) of patients in the intervention group were higher than those of patients in the control group. Ventilator support time (P=0.004), CICU stay (P=0.045), and infection rate (P=0.001) were significantly lower in the intervention group than the control group. At 3 months post-surgery, the intervention group exhibited a higher malnutrition recovery rate than the control group (19.4% vs. 6.5%; P=0.002).

CONCLUSIONS

The administration of early high-energy feeding to infants after congenital heart surgery is associated with improved growth, reduced CICU stay, decreased ventilator support time, and reduced postoperative infection rates.

TRIAL REGISTRATION

ClinicalTrials NCT04609358.

Genetic evaluation of newborns with critical congenital heart defects admitted to the intensive care unit

Rapid and efficient diagnostics is crucial for newborns with congenital heart defects (CHD) in intensive care unit (ICU) but is often challenging. Given that genetic factors play a role in 20-30% cases of CHD, it is likely that genetic tests could improve both its speed and efficiency. We aimed to analyze the utility of rapid and cost-effective multiplex ligation dependent probe amplification analysis (MLPA) for chromosomal analysis in newborns with critical CHD. One hundred consecutive newborns admitted with critical CHD to the ICU were included in the study. Those with normal MLPA findings were further tested by chromosomal microarray and clinical exome sequencing. Overall, pathogenic/likely pathogenic variants were determined in ten (10%) newborns by MLPA, three (3%) by chromosomal microarray, and three (3%) by clinical exome sequencing. The most common variant detected was deletion of 22q11.2 region.Conclusion: MLPA is fast and cost-effective analysis that could be used as the first-tier test in newborns with critical CHD admitted to the ICU. What is Known: • MLPA is an established method for chromosome analysis in patients with CHD, but detection rate in newborns with critical CHD is unknown. What is New: • Study suggests that detection rate of casual variants using MLPA in newborns with critical CHD is 10%.

Fetal Ultrasonic Evaluation of Bronchial Morphology in Fetuses with Isomerism

OBJECTIVE

The aim of the study was to evaluate whether fetal ultrasound could determine bronchial isomerism and distinguish left isomerism from right isomerism.

METHODS

We identified 110 healthy fetuses and 28 fetuses with isomerism. The outer angle between the tracheal midline and the inner margin of the bronchus is measured. The bronchial angles and the ratio of left/right bronchial angle were used to differentiate bronchial morphology and confirm the presence of bronchial isomerism in pathological cases.

RESULTS

The normal angles of the left and right bronchi were 146.98° (95% CI, 145.15-147.81°) and 167.37° (95% CI, 166.30-168.44°), separately. The cutoff bronchial angle of 156.5° was used to distinguish left bronchus from right bronchus. The bronchial isomerism could be identified in all pathological cases by autopsy and bronchial-atrial concordance occurred in 27 pathological cases (96.4%). In 21 pathological cases, the bilateral bronchial angle was <156.5 versus >156.5 differentiated left from right isomerism, respectively. The ratio of the left/right bronchial angle of >0.935 identified 92.9% (26/28) of all pathological cases, with a sensitivity of 89.7%.

CONCLUSIONS

Fetal ultrasound can detect the bronchial morphology and the presence of bronchial isomerism in fetuses with isomerism according to bronchial angles and the ratio of left/right bronchial angle.

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.

Congenital heart defects and copy number variants associated with neurodevelopmental impairment

A genetic etiology is identifiable in 20%-30% of patients with congenital heart defects (CHD). Chromosomal microarray analysis (CMA) can detect copy number variants (CNV) associated with CHD. In previous studies, the diagnostic yield of postnatal CMA testing ranged from 4% to 28% in CHD patients. However, incidental pathogenic CNV and variants of unknown significance are often discovered without any known association with CHD. The study objective was to describe the rate of pathogenic CNV associated with neurodevelopmental impairment (NDI) and compare clinical findings in CHD neonates with genetic results. A single-center retrospective review was performed on all consecutive newborns with CHD admitted to a tertiary neonatal intensive care unit from January 2013 to March 2019 (n = 525). CHD phenotypes were classified as per the National Birth Defect Prevention Study. CMA detected pathogenic CNV in 21.3% (61/287) of neonates, and karyotype or fluorescence in situ hybridization detected aneuploidies in an additional 11% of the overall cohort (58/525). Atrioventricular septal defects and conotruncal defects showed the highest diagnostic yield by CMA (28.6% and 27.2%, respectively). Among neonates with pathogenic CNV on CMA, 78.7% (48/61) were associated with NDI. Neonates with pathogenic CNV were smaller in length at birth compared to those with benign CNV or variants of unknown significance (p = 0.005) and were more likely to be discharged with an enteral feeding tube (p = 0.027). CMA can discover genetic variants associated with NDI and are common in neonates with CHD. Genetic testing in the neonatal period can heighten awareness of genetic risk for NDI.

Identification of variants of ISL1 gene promoter and cellular functions in isolated ventricular septal defects

Ventricular septal defects (VSDs) are the most common congenital heart defects (CHDs). Studies have documented that ISL1 has a crucial impact on cardiac growth, but the role of variants in the ISL1 gene promoter in patients with VSD has not been explored. In 400 subjects (200 patients with isolated and sporadic VSDs: 200 healthy controls), we investigated the ISL1 gene promoter variant and performed cellular functional experiments by using the dual-luciferase reporter assay to verify the impact on gene expression. In the ISL1 promoter, five variants were found only in patients with VSD by sequencing. Cellular functional experiments demonstrated that three variants decreased the transcriptional activity of the ISL1 promoter (P < 0.05). Further analysis with the online JASPAR database demonstrated that a cluster of putative binding sites for transcription factors may be altered by these variants, possibly resulting in change of ISL1 protein expression and VSD formation. Our study has, for the first time, identified novel variants in the ISL1 gene promoter region in the Han Chinese patients with isolated and sporadic VSD. In addition, the cellular functional experiments, electrophoretic mobility shift assay, and bioinformatic analysis have demonstrated that these variants significantly alter the expression of the ISL1 gene and affect the binding of transcription factors, likely resulting in VSD. Therefore, this study may provide new insights into the role of the gene promoter region for a better understanding of genetic basis of the formation of CHDs and may promote further investigations on mechanism of the formation of CHDs.

Genetics of congenital heart disease: a narrative review of recent advances and clinical implications

Congenital heart disease (CHD) is the most common human birth defect and remains a leading cause of mortality in childhood. Although advances in clinical management have improved the survival of children with CHD, adult survivors commonly experience cardiac and non-cardiac comorbidities, which affect quality of life and prognosis. Therefore, the elucidation of genetic etiologies of CHD not only has important clinical implications for genetic counseling of patients and families but may also impact clinical outcomes by identifying at-risk patients. Recent advancements in genetic technologies, including massively parallel sequencing, have allowed for the discovery of new genetic etiologies for CHD. Although variant prioritization and interpretation of pathogenicity remain challenges in the field of CHD genomics, advances in single-cell genomics and functional genomics using cellular and animal models of CHD have the potential to provide novel insights into the underlying mechanisms of CHD and its associated morbidities. In this review, we provide an updated summary of the established genetic contributors to CHD and discuss recent advances in our understanding of the genetic architecture of CHD along with current challenges with the interpretation of genetic variation. Furthermore, we highlight the clinical implications of genetic findings to predict and potentially improve clinical outcomes in patients with CHD.

HIF in the heart: development, metabolism, ischemia, and atherosclerosis

The heart forms early in development and delivers oxygenated blood to the rest of the embryo. After birth, the heart requires kilograms of ATP each day to support contractility for the circulation. Cardiac metabolism is omnivorous, utilizing multiple substrates and metabolic pathways to produce this energy. Cardiac development, metabolic tuning, and the response to ischemia are all regulated in part by the hypoxia-inducible factors (HIFs), central components of essential signaling pathways that respond to hypoxia. Here we review the actions of HIF1, HIF2, and HIF3 in the heart, from their roles in development and metabolism to their activity in regeneration and preconditioning strategies. We also discuss recent work on the role of HIFs in atherosclerosis, the precipitating cause of myocardial ischemia and the leading cause of death in the developed world.

A Multi-Omics Approach Using a Mouse Model of Cardiac Malformations for Prioritization of Human Congenital Heart Disease Contributing Genes

Congenital heart disease (CHD) is the most common type of birth defect, affecting ~1% of all live births. Malformations of the cardiac outflow tract (OFT) account for ~30% of all CHD and include a range of CHDs from bicuspid aortic valve (BAV) to tetralogy of Fallot (TOF). We hypothesized that transcriptomic profiling of a mouse model of CHD would highlight disease-contributing genes implicated in congenital cardiac malformations in humans. To test this hypothesis, we utilized global transcriptional profiling differences from a mouse model of OFT malformations to prioritize damaging, de novo variants identified from exome sequencing datasets from published cohorts of CHD patients. Notch1 +/- ; Nos3 -/- mice display a spectrum of cardiac OFT malformations ranging from BAV, semilunar valve (SLV) stenosis to TOF. Global transcriptional profiling of the E13.5 Notch1 +/- ; Nos3 -/- mutant mouse OFTs and wildtype controls was performed by RNA sequencing (RNA-Seq). Analysis of the RNA-Seq dataset demonstrated genes belonging to the Hif1α, Tgf-β, Hippo, and Wnt signaling pathways were differentially expressed in the mutant OFT. Mouse to human comparative analysis was then performed to determine if patients with TOF and SLV stenosis display an increased burden of damaging, genetic variants in gene homologs that were dysregulated in Notch1 +/- ; Nos3 -/- OFT. We found an enrichment of de novo variants in the TOF population among the 1,352 significantly differentially expressed genes in Notch1 +/- ; Nos3 -/- mouse OFT but not the SLV population. This association was not significant when comparing only highly expressed genes in the murine OFT to de novo variants in the TOF population. These results suggest that transcriptomic datasets generated from the appropriate temporal, anatomic and cellular tissues from murine models of CHD may provide a novel approach for the prioritization of disease-contributing genes in patients with CHD.

Genetic Evaluation of Inpatient Neonatal and Infantile Congenital Heart Defects: New Findings and Review of the Literature

The use of clinical genetics evaluations and testing for infants with congenital heart defects (CHDs) is subject to practice variation. This single-institution cross-sectional study of all inpatient infants with severe CHDs evaluated 440 patients using a cardiovascular genetics service (2014–2019). In total, 376 (85.5%) had chromosome microarray (CMA), of which 55 (14.6%) were diagnostic in syndromic (N = 35) or isolated (N = 20) presentations. Genetic diagnoses were made in all CHD classes. Diagnostic yield was higher in syndromic appearing infants, but geneticists’ dysmorphology exams lacked complete sensitivity and 6.5% of isolated CHD cases had diagnostic CMA. Interestingly, diagnostic results (15.8%) in left ventricular outflow tract obstruction (LVOTO) defects occurred most often in patients with isolated CHD. Geneticists’ evaluations were particularly important for second-tier molecular testing (10.5% test-specific yield), bringing the overall genetic testing yield to 17%. We assess these results in the context of previous studies. Cumulative evidence provides a rationale for comprehensive, standardized genetic evaluation in infants with severe CHDs regardless of lesion or extracardiac anomalies because genetic diagnoses that impact care are easily missed. These findings support routine CMA testing in infants with severe CHDs and underscore the importance of copy-number analysis with newer testing strategies such as exome and genome sequencing.

Recessive ciliopathy mutations in primary endocardial fibroelastosis: a rare neonatal cardiomyopathy in a case of Alstrom syndrome

Abstract

Among neonatal cardiomyopathies, primary endocardial fibroelastosis (pEFE) remains a mysterious disease of the endomyocardium that is poorly genetically characterized, affecting 1/5000 live births and accounting for 25% of the entire pediatric dilated cardiomyopathy (DCM) with a devastating course and grave prognosis. To investigate the potential genetic contribution to pEFE, we performed integrative genomic analysis, using whole exome sequencing (WES) and RNA-seq in a female infant with confirmed pathological diagnosis of pEFE. Within regions of homozygosity in the proband genome, WES analysis revealed novel parent-transmitted homozygous mutations affecting three genes with known roles in cilia assembly or function. Among them, a novel homozygous variant [c.1943delA] of uncertain significance in ALMS1 was prioritized for functional genomic and mechanistic analysis. Loss of function mutations of ALMS1 have been implicated in Alstrom syndrome (AS) [OMIM 203800], a rare recessive ciliopathy that has been associated with cardiomyopathy. The variant of interest results in a frameshift introducing a premature stop codon. RNA-seq of the proband’s dermal fibroblasts confirmed the impact of the novel ALMS1 variant on RNA-seq reads and revealed dysregulated cellular signaling and function, including the induction of epithelial mesenchymal transition (EMT) and activation of TGFβ signaling. ALMS1 loss enhanced cellular migration in patient fibroblasts as well as neonatal cardiac fibroblasts, while ALMS1-depleted cardiomyocytes exhibited enhanced proliferation activity. Herein, we present the unique pathological features of pEFE compared to DCM and utilize integrated genomic analysis to elucidate the molecular impact of a novel mutation in ALMS1 gene in an AS case. Our report provides insights into pEFE etiology and suggests, for the first time to our knowledge, ciliopathy as a potential underlying mechanism for this poorly understood and incurable form of neonatal cardiomyopathy.

Key message

Primary endocardial fibroelastosis (pEFE) is a rare form of neonatal cardiomyopathy that occurs in 1/5000 live births with significant consequences but unknown etiology.

Integrated genomics analysis (whole exome sequencing and RNA sequencing) elucidates novel genetic contribution to pEFE etiology.

In this case, the cardiac manifestation in Alstrom syndrome is pEFE. To our knowledge, this report provides the first evidence linking ciliopathy to pEFE etiology.

Infants with pEFE should be examined for syndromic features of Alstrom syndrome.

Our findings lead to a better understanding of the molecular mechanisms of pEFE, paving the way to potential diagnostic and therapeutic applications.

Supplementary information

The online version contains supplementary material available at 10.1007/s00109-021-02112-z.

The current state of prenatal detection of genetic conditions in congenital heart defects

The incidence of congenital heart defect (CHD) has increased over the past fifty years, partly attributed to routine fetal anatomical examination by sonography during obstetric care and improvements in ultrasound technology and technique. Fetal findings on ultrasound in addition to maternal biomarkers are the backbone of first- and second-trimester screening for common genetic conditions, namely aneuploidy. Since the introduction of non-invasive prenatal testing (NIPT) using next-generation sequencing to sequence cell-free fetal DNA, the detection rate of common trisomies as well as sex chromosomal aneuploidies have markedly increased. As the use of NIPT continues to broaden, the best means of incorporating NIPT into prenatal care is less clear and complicated by misunderstanding of the limitations and non-diagnostic role of NIPT by clinicians and families. In other advancements in prenatal genetic testing, recommendations on the role of chromosomal microarray (CMA) for prenatal diagnosis has led to its increasing use to identify genetic conditions in fetuses diagnosed with CHD. Lastly, as whole exome sequencing (WES) becomes more available and affordable, the next clinical application of next-generation sequencing in prenatal diagnostic testing is on the horizon. While newer genetic tests may provide answers in terms of genetic diagnosis, even more questions will likely ensue for clinicians, researchers, and parents. The objective of this review is to provide the perspective of the evolution of maternal and fetal obstetric care against the backdrop of advancing genetic technology and its impact on families and clinicians.

Individuals aged 1-64 years with documented congenital heart defects at healthcare encounters, five U.S. surveillance sites, 2011-2013

BACKGROUND

Many individuals born with congenital heart defects (CHD) survive to adulthood. However, population estimates of CHD beyond early childhood are limited in the U.S.

OBJECTIVES

To estimate the percentage of individuals aged 1-to-64 years at five U.S. sites with CHD documented at a healthcare encounter during a three-year period and describe their characteristics.

METHODS

Sites conducted population-based surveillance of CHD among 1 to 10-year-olds (three sites) and 11 to 64-year-olds (all five sites) by linking healthcare data. Eligible cases resided in the population catchment areas and had one or more healthcare encounters during the surveillance period (January 1, 2011-December 31, 2013) with a CHD-related ICD-9-CM code. Site-specific population census estimates from the same age groups and time period were used to assess percentage of individuals in the catchment area with a CHD-related ICD-9-CM code documented at a healthcare encounter (hereafter referred to as CHD cases). Severe and non-severe CHD were based on an established mutually exclusive anatomic hierarchy.

RESULTS

Among 42,646 CHD cases, 23.7% had severe CHD and 51.5% were male. Percentage of CHD cases among 1 to 10-year-olds, was 6.36/1,000 (range: 4.33-9.96/1,000) but varied by CHD severity [severe: 1.56/1,000 (range: 1.04-2.64/1,000); non-severe: 4.80/1,000 (range: 3.28-7.32/1,000)]. Percentage of cases across all sites in 11 to 64-year-olds was 1.47/1,000 (range: 1.02-2.18/1,000) and varied by CHD severity [severe: 0.34/1,000 (range: 0.26-0.49/1,000); non-severe: 1.13/1,000 (range: 0.76-1.69/1,000)]. Percentage of CHD cases decreased with age until 20 to 44 years and, for non-severe CHD only, increased slightly for ages 45 to 64 years.

CONCLUSION

CHD cases varied by site, CHD severity, and age. These findings will inform planning for the needs of this growing population.

Parental Attitudes Toward Clinical Genomic Sequencing in Children With Critical Cardiac Disease

OBJECTIVES

Through improving diagnostics and prognostics genomic sequencing promises to significantly impact clinical decisions for children with critical cardiac disease. Little is known about how families of children with critical cardiac disease perceive the impact of genomic sequencing on clinical care choices.

DESIGN

Qualitative interview study.

SETTING

A high-volume, tertiary pediatric heart center.

SUBJECTS

Families of children with critical cardiac disease.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Thematic analysis of interview response content. Thirty-five families were interviewed. Three themes emerged: 1) benefits versus challenges of having genomic sequencing results, and 2) fears of clinical applications of genomic sequencing, and 3) nonclinical fears related to genomic sequencing. Participants struggled with perceived uses of genomic sequencing-derived knowledge. They described comfort in foreknowledge of their child's likely disease course but articulated significant apprehension around participating in care decisions with limited knowledge of genomic sequencing, genomic sequencing uses to inform clinical resource rationing decisions, and genomic sequencing uses by third parties impacting financial pressures families experience caring for a child with critical cardiac disease.

CONCLUSIONS

Families' perceptions of genomic sequencing uses in critical cardiac disease appear to strain their overall trust in the health system. Erosion of trust is concerning because the potential of genomic sequencing in critical cardiac disease will be unrealized if families are unwilling to undergo genomic sequencing, let alone to participate in the ongoing research needed to link genomic sequencing variants to clinical outcomes. Our findings may have implications for genomic sequencing use in children with other critical, high-acuity diseases.

Epidemiology of Pediatric Heart Failure in the USA-a 15-Year Multi-Institutional Study

The epidemiology of pediatric heart failure (HF) has been characterized for congenital heart disease (CHD) and cardiomyopathies (CM), but the impact of CM associated with CHD has not been studied. This study aims to describe the characteristics and outcomes of inpatient pediatric HF patients with CHD, CM, and CHD with CM (CHD + CM) across the USA. We included all HF patients with CM diagnoses with and without CHD using ICD 9/10 codes ≤ 19 years old from January 2004 to September 2019 using the Pediatric Health Information System database. We identified 67,349 unique patients ≤ 19 years old with HF, of which 87% had CHD, 7% had CHD + CM, and 6% had CM. Pediatric HF admissions increased significantly from 2004 to 2018 with an associated increase in extracorporeal circulatory support (ECLS) use. Heart transplantation (HTX) increased only in the CHD and CHD + CM groups. CHD patients required less ECLS with and without HTX; however, they had significantly higher inpatient mortality after those procedures than the other groups (p < 0.001). CM patients were older (median 115 months) and had the lowest inpatient mortality after HTX with and without ECLS (p < 0.05). CHD + CM showed the highest overall inpatient mortality (15%), and cumulative hospital billed charges (median US$ 541,374), all p < 0.001. Pediatric HF admissions have increased from 2004 to 2018. ECLS use and HTX have expanded in this population, with an associated decrease in inpatient mortality in the CHD and CM groups. CHD + CM patients are a growing population with the highest inpatient mortality.

First-Trimester Maternal Folic Acid Supplementation Modifies the Effects of Risk Factors Exposures on Congenital Heart Disease in Offspring

This study aimed to examine effect modification of maternal risk factor exposures and congenital heart disease (CHD) by maternal folic acid supplementation (FAS)/non-FAS. We included 8379 CHD cases and 6918 CHD-free controls from 40 clinical centers in Guangdong Province, Southern China, 2004-2016. Controls were randomly chosen from malformation-free fetuses and infants and frequency matched to the echocardiogram-confirmed cases by enrollment hospital and year of birth. We used multiple regression models to evaluate interactions between FAS/non-FAS and risk factors on CHDs and major CHD categories, adjusted for confounding variables. We detected statistically significant additive and multiplicative interactions between maternal FAS/non-FAS and first-trimester fever, viral infection, and threatened abortion on CHDs. An additive interaction on CHDs was also identified between non-FAS and living in a newly renovated home. We observed a statistically significant dose-response relationship between non-FAS and a greater number of maternal risk factors on CHDs. Non-FAS and maternal risk factors interacted additively on multiple critical CHDs, conotruncal defects, and right ventricular outflow tract obstruction. Maternal risk factor exposures may have differential associations with CHD risk in offspring, according to FAS. These findings may inform the design of targeted interventions to prevent CHDs in highly susceptible population groups.

Congenital Heart Disease

Most children with congenital heart disease (CHD) survive to adulthood, owing largely to significant advances in the diagnosis and management of CHD over the past few decades. Primary care providers are essential partners in the recognition and management of these patients in our current medical environment. This article reviews the role of the primary care physician in detecting fetuses, infants, and children with possible CHD. Furthermore, this article discusses common primary care issues arising for patients with CHD, including growth and development, mental illness, dental care, and the transition to adult primary care.

Whole-exome sequencing reveals a monogenic cause in 56% of individuals with laterality disorders and associated congenital heart defects

BACKGROUND

The molecular basis of heterotaxy and congenital heart malformations associated with disruption of left-right asymmetry is broad and heterogenous, with over 25 genes implicated in its pathogenesis thus far.

OBJECTIVE

We sought to elucidate the molecular basis of laterality disorders and associated congenital heart defects in a cohort of 30 unrelated probands of Arab-Muslim descent, using next-generation sequencing techniques.

METHODS

Detailed clinical phenotyping followed by whole-exome sequencing (WES) was pursued for each of the probands and their parents (when available). Sanger sequencing was used for segregation analysis of disease-causing mutations in the families.

RESULTS

Using WES, we reached a molecular diagnosis for 17 of the 30 probands (56.7%). Genes known to be associated with heterotaxy and/or primary ciliary dyskinesia, in which homozygous pathogenic or likely pathogenic variants were detected, included CFAP53 (CCDC11), CFAP298 (C21orf59), CFAP300, LRRC6, GDF1, DNAAF1, DNAH5, CCDC39, CCDC40, PKD1L1 and TTC25. Additionally, we detected a homozygous disease causing mutation in DAND5, as a novel recessive monogenic cause for heterotaxy in humans. Three additional probands were found to harbour variants of uncertain significance. These included variants in DNAH6, HYDIN, CELSR1 and CFAP46.

CONCLUSIONS

Our findings contribute to the current knowledge regarding monogenic causes of heterotaxy and its associated congenital heart defects and underscore the role of next-generation sequencing techniques in the diagnostic workup of such patients, and especially among consanguineous families.

Molecular Genetics and Complex Inheritance of Congenital Heart Disease

Congenital heart disease (CHD) is the most common congenital malformation and the leading cause of mortality therein. Genetic etiologies contribute to an estimated 90% of CHD cases, but so far, a molecular diagnosis remains unsolved in up to 55% of patients. Copy number variations and aneuploidy account for ~23% of cases overall, and high-throughput genomic technologies have revealed additional types of genetic variation in CHD. The first CHD risk genotypes identified through high-throughput sequencing were de novo mutations, many of which occur in chromatin modifying genes. Murine models of cardiogenesis further support the damaging nature of chromatin modifying CHD mutations. Transmitted mutations have also been identified through sequencing of population scale CHD cohorts, and many transmitted mutations are enriched in cilia genes and Notch or VEGF pathway genes. While we have come a long way in identifying the causes of CHD, more work is required to end the diagnostic odyssey for all CHD families. Complex genetic explanations of CHD are emerging but will require increasingly sophisticated analysis strategies applied to very large CHD cohorts before they can come to fruition in providing molecular diagnoses to genetically unsolved patients. In this review, we discuss the genetic architecture of CHD and biological pathways involved in its pathogenesis.

Identification and functional study of GATA4 gene regulatory variants in atrial septal defects

Background

Congenital heart disease (CHD) is the leading cause of mortality from birth defects. In adult CHD patients with successful surgical repair, cardiac complications including heart failure develop at late stage, likely due to genetic causes. To date, many mutations in cardiac developmental genes have been associated with CHD. Recently, regulatory variants in genes have been linked to many human diseases. Although mutations and splicing variants in GATA4 gene have been reported in CHD patients, few regulatory variants of GATA4 gene are identified in CHD patients.

Methods

GATA4 gene regulatory region was investigated in the patients with atrial septal defects (ASD) (n = 332) and ethnic-matched controls (n = 336).

Results

Five heterozygous regulatory variants including four SNPs [g.31360 T>C (rs372004083), g.31436G>A, g.31437C>A (rs769262495), g.31487C>G (rs1053351749) and g.31856C>T (rs1385460518)] were only identified in ASD patients. Functional analysis indicated that the regulatory variants significantly affected the transcriptional activity of GATA4 gene promoter. Furthermore, two of the five regulatory variants have evidently effected on transcription factor binding sites.

Conclusions

Our data suggested that GATA4 gene regulatory variants may confer ASD susceptibility by decreasing GATA4 levels.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02136-w.

Hypertrophic Cardiomyopathy in Infants from the Perspective of Cardiomyocyte Maturation

Hypertrophic cardiomyopathy (HCM) in infancy is rare and many fulminant cases are fatal. Infantile HCM shows a rapid progressive clinical course and different characteristics compared with late-onset HCM presenting during the prepubertal age. There are also spontaneously resolving phenotypes of HCM that are diagnosed in neonates being treated for bronchopulmonary dysplasia with corticosteroids or in those with other problems related to maternal endocrine diseases. The pathophysiology of infantile HCM has not been well described. Therefore, this review updates the pathophysiology of infantile HCM and includes molecular studies on maturation of cardiomyocytes from a clinician's point of view.

Hypertrophic cardiomyopathy (HCM) is characterized by ventricular wall hypertrophy with diastolic dysfunction. Pediatric HCM is distinguished from the adult in many aspects. Most children with HCM do not present clinically until the adolescent period, even when they are born with genetic mutations. Some infants with early-onset HCM present with massive progressive myocardial hypertrophy in the first few months of life, which is often fatal. The mortality of pediatric HCM peaks during the infantile and adolescent periods. These periods roughly correlate with children's growth spurt. Non-sarcomeric causes of HCM are more frequent in pediatric HCM, while sarcomeric causes are more common in adults. From the perspective of cardiac development, the fetal heart has immature cardiomyocytes, which are characterized by proliferation and exit their cell cycles with a decreased regenerative property after birth. In the perinatal period, there is a dynamic change in maturation of cardiomyocytes from immature to mature cells. Infants who are treated with steroids or born to mothers with diabetes or hyperthyroidism often show phenotypes of HCM, which gradually resolve. With remarkable advancement of molecular biology, understanding on maturation of cardiomyocytes has increased. Neonates undergo abrupt environmental changes during the transitional circulation, which is affected by oxygen, metabolic and hormonal fluctuations. Derangement in physiological transition to the normal postnatal environment may influence maturation of proliferative immature cardiomyocytes during early infancy. This article reviews updates of infantile HCM and recent molecular studies related to maturation of cardiomyocytes from the clinical point of view of identifying distinct characteristics of infantile HCM.

Personalized Genetic Diagnosis of Congenital Heart Defects in Newborns

Congenital heart disease is a group of pathologies characterized by structural malformations of the heart or great vessels. These alterations occur during the embryonic period and are the most frequently observed severe congenital malformations, the main cause of neonatal mortality due to malformation, and the second most frequent congenital malformations overall after malformations of the central nervous system. The severity of different types of congenital heart disease varies depending on the combination of associated anatomical defects. The causes of these malformations are usually considered multifactorial, but genetic variants play a key role. Currently, use of high-throughput genetic technologies allows identification of pathogenic aneuploidies, deletions/duplications of large segments, as well as rare single nucleotide variants. The high incidence of congenital heart disease as well as the associated complications makes it necessary to establish a diagnosis as early as possible to adopt the most appropriate measures in a personalized approach. In this review, we provide an exhaustive update of the genetic bases of the most frequent congenital heart diseases as well as other syndromes associated with congenital heart defects, and how genetic data can be translated to clinical practice in a personalized approach.

Risk factors of postoperative acute kidney injury in patients with complex congenital heart disease and significance of early detection of serum transcription factor Nkx2.5

OBJECTIVE

This study was designed to investigate the risk factors of postoperative acute kidney injury (AKI) in patients with complex congenital heart disease (CHD) and the significance of early detection of serum transcription factor Nkx2.5.

METHODS

A total of 121 CHD patients admitted to the Shengli Clinical Medical College of Fujian Medical University were selected as study participants, among whom 69 patients with AKI after cardiac surgery were set as the research group (RG), and the rest of the 52 patients without AKI were set as the control group (CG). Cardiopulmonary bypass (CPB) duration, aortic occlusion time, postoperative creatinine (Cr) level and mechanical ventilation (MV) time were compared between the two groups. The expression and clinical significance of Nkx2.5 in the two groups were detected. Intensive Care Unit (ICU) residence time and total hospital stay were compared, and the risk factors were analyzed.

RESULTS

The RG presented remarkably longer CPB duration and aortic occlusion time, evidently higher postoperative Cr level and longer MV time, and observably lower Nkx2.5 level in comparison to the CG (all P<0.05). According to the analysis of receiver operating characteristic (ROC) curves, Nkx2.5 displayed a favorable diagnostic value in predicting the occurrence of CHD complicated with AKI. ICU residence time and total hospital stay were longer in the RG than in the CG (P<0.05). CPB time and aortic occlusion time were independent risk factors for AKI in CHD patients, while surgical methods and Nkx2.5 detection were independent protective factors (P<0.05).

CONCLUSIONS

CPB time, aortic occlusion time and surgical methods, as well as Nkx2.5 detection are independent factors affecting AKI in patients with CHD. Early detection of serum transcription factor Nkx2.5 is of particular importance for clinical diagnosis of CHD patients complicated with AKI.

Getting to the Heart of Left-Right Asymmetry: Contributions from the Zebrafish Model

The heart is laterally asymmetric. Not only is it positioned on the left side of the body but the organ itself is asymmetric. This patterning occurs across scales: at the organism level, through left-right axis patterning; at the organ level, where the heart itself exhibits left-right asymmetry; at the cellular level, where gene expression, deposition of matrix and proteins and cell behaviour are asymmetric; and at the molecular level, with chirality of molecules. Defective left-right patterning has dire consequences on multiple organs; however, mortality and morbidity arising from disrupted laterality is usually attributed to complex cardiac defects, bringing into focus the particulars of left-right patterning of the heart. Laterality defects impact how the heart integrates and connects with neighbouring organs, but the anatomy of the heart is also affected because of its asymmetry. Genetic studies have demonstrated that cardiac asymmetry is influenced by left-right axis patterning and yet the heart also possesses intrinsic laterality, reinforcing the patterning of this organ. These inputs into cardiac patterning are established at the very onset of left-right patterning (formation of the left-right organiser) and continue through propagation of left-right signals across animal axes, asymmetric differentiation of the cardiac fields, lateralised tube formation and asymmetric looping morphogenesis. In this review, we will discuss how left-right asymmetry is established and how that influences subsequent asymmetric development of the early embryonic heart. In keeping with the theme of this issue, we will focus on advancements made through studies using the zebrafish model and describe how its use has contributed considerable knowledge to our understanding of the patterning of the heart.

Heart Development and Congenital Structural Heart Defects

Congenital heart disease is the most frequent birth defect and the leading cause of death for the fetus and in the first year of life. The wide phenotypic diversity of congenital heart defects requires expert diagnosis and sophisticated repair surgery. Although these defects have been described since the seventeenth century, it was only in 2005 that a consensus international nomenclature was adopted, followed by an international classification in 2017 to help provide better management of patients. Advances in genetic engineering, imaging, and omics analyses have uncovered mechanisms of heart formation and malformation in animal models, but approximately 80% of congenital heart defects have an unknown genetic origin. Here, we summarize current knowledge of congenital structural heart defects, intertwining clinical and fundamental research perspectives, with the aim to foster interdisciplinary collaborations at the cutting edge of each field. We also discuss remaining challenges in better understanding congenital heart defects and providing benefits to patients.

LZTR1: A promising adaptor of the CUL3 family

The study of the disorders of ubiquitin-mediated proteasomal degradation may unravel the molecular basis of human diseases, such as cancer (prostate cancer, lung cancer and liver cancer, etc.) and nervous system disease (Parkinson's disease, Alzheimer's disease and Huntington's disease, etc.) and help in the design of new therapeutic methods. Leucine zipper-like transcription regulator 1 (LZTR1) is an important substrate recognition subunit of cullin-RING E3 ligase that plays an important role in the regulation of cellular functions. Mutations in LZTR1 and dysregulation of associated downstream signaling pathways contribute to the pathogenesis of Noonan syndrome (NS), glioblastoma and chronic myeloid leukemia. Understanding the molecular mechanism of the normal function of LZTR1 is thus critical for its eventual therapeutic targeting. In the present review, the structure and function of LZTR1 are described. Moreover, recent advances in the current knowledge of the functions of LZTR1 in NS, glioblastoma (GBM), chronic myeloid leukemia (CML) and schwannomatosis and the influence of LZTR1 mutations are also discussed, providing insight into how LZTR1 may be targeted for therapeutic purposes.

Di-2-ethylhexyl phthalate induces heart looping disorders during zebrafish development

Di-2-ethylhexyl phthalate (DEHP) is a type of plasticizer widely used in industry. It is well-known for its toxic effects to endocrine and reproductive systems and has been detected in amniotic fluid and placenta. In the present study, we explored the effects of DEHP on heart development by using zebrafish as a model organism. DEHP (0.02 pg) was injected into the yolk sac of zebrafish embryos at the one-cell stage. No significant difference was found in embryonic lethality between control and DEHP groups at 1-day postfertilization (dpf), but mortality significantly increased in DEHP groups at 2 and 3 dpf. The average heart rate was significantly reduced in the surviving DEHP-treated zebrafish larvae at 3 and 4 dpf. In addition, massive pericardial edema was found in DEHP-treated zebrafish (12.6 ± 1.5%), which was significantly higher than that of the control group. Serious heart looping disorder was also observed in DEHP-treated larvae, mainly manifested with an elongated atrial-ventricular distance. Moreover, the expression of heart development transcription factors was affected by DEHP injection. Real-time polymerase chain reaction confirmed that five transcription factors (hand2, tp53, mef2c, esr1, and tbx18) were significantly downregulated in the DEHP group at 2 dpf, and three transcription factors (zic3, tcf21, and gata4) were significantly upregulated. Our results emphasize the need for the development of a nontoxic plasticizer to prevent possible deleterious effects on humans and other life-forms.

Focused Strategies for Defining the Genetic Architecture of Congenital Heart Defects

Congenital heart defects (CHD) are malformations present at birth that occur during heart development. Increasing evidence supports a genetic origin of CHD, but in the process important challenges have been identified. This review begins with information about CHD and the importance of detailed phenotyping of study subjects. To facilitate appropriate genetic study design, we review DNA structure, genetic variation in the human genome and tools to identify the genetic variation of interest. Analytic approaches powered for both common and rare variants are assessed. While the ideal outcome of genetic studies is to identify variants that have a causal role, a more realistic goal for genetic analytics is to identify variants in specific genes that influence the occurrence of a phenotype and which provide keys to open biologic doors that inform how the genetic variants modulate heart development. It has never been truer that good genetic studies start with good planning. Continued progress in unraveling the genetic underpinnings of CHD will require multidisciplinary collaboration between geneticists, quantitative scientists, clinicians, and developmental biologists.