Syndromic cardiac malformations can result in morbidity, yet their genetic etiology is only understood for a subset of individuals. Genome sequencing efforts in congenital anomaly cohorts may identify disease-associated variants in previously unrecognized genes. Through international matchmaking efforts, we identified eighteen individuals in total with de novo or loss-of-function variants in EIF3A (n = 4) or EIF3B (n = 14). The clinical phenotype varied but predominantly included cardiac defects, craniofacial dysmorphisms, mild developmental delays, and behavioral abnormalities. These genes encode core subunits of the eukaryotic initiation factor 3 (eIF3) complex, which plays a critical role in binding mRNA transcripts to the 40S ribosomal subunit during translation initiation. Both genes are highly constrained against loss of function, and animal models have demonstrated that disruptions in the eIF3 complex result in a range of developmental defects, including cardiovascular malformations. Additionally, EIF3B is located within the minimally overlapping region implicated in cardiac anomalies associated with 7p22.3 microdeletions. We sought to further study the role of these genes in syndromic congenital heart disease. To explore their functional impact, we generated zebrafish models with mutations in the orthologous eif3s10 and eif3ba genes, which resulted in developmental abnormalities, including thin heart tubes, lack of craniofacial cartilage, and embryonic lethality. We propose that pathogenic variants in EIF3A, as well as pathogenic variants or microdeletions involving EIF3B, cause a distinct autosomal-dominant neurodevelopmental syndrome characterized by cardiovascular and craniofacial manifestations.

Genetic cardiomyopathies commonly cause end-stage heart failure, yet genetic testing is inconsistently applied in heart transplant recipients. Identifying pathogenic/likely pathogenic (P/LP) variants clarifies etiology and informs familial risk, but data on diagnostic yield are limited. We performed a meta-analysis to quantify genetic testing yield in heart transplant recipients and implications for cascade testing. MEDLINE and Embase were searched for studies examining cardiomyopathy-focused genetic testing in heart transplant recipients. Pooled P/LP cardiomyopathy variant yields were estimated using random-effects models, stratified by cardiomyopathy phenotype. Cascade testing outcomes were summarized. Eleven studies met inclusion criteria. Overall, 32% (95% CI: 21-46%) of heart transplant recipients carried a P/LP variant. Yield was highest in non-ischemic cardiomyopathy (34%, 95% CI: 24-47%) and non-ischemic dilated cardiomyopathy cohorts (29%, 95% CI: 12-54%), and lowest in ischemic cardiomyopathy cohorts (8%, 95% CI: 4-18%). Heterogeneity ranged from I2 35% to 92%. Among studies reporting cascade testing outcomes, 52-92% of families underwent testing; 30-40% of relatives had P/LP variants, 15-69% of which demonstrated a phenotypic CM. While exact estimates should be interpreted cautiously given heterogeneity across cohorts, the consistency of findings suggests meaningful clinical relevance. Cardiomyopathy-focused genetic testing identifies P/LP variants in many heart transplant recipients, with important implications for cascade testing, supporting integration of cardiomyopathy-related genetic evaluation into heart transplant programs.

Bicuspid aortic valve (BAV) is the most common congenital heart lesion in adults and is often associated with thoracic aortic aneurysms and aortic stenosis. The genetic causes of most non-syndromic cases of BAV remain unknown. Pathogenic variants in COL1A1 or COL1A2, which encode type I collagen (COL1), cause osteogenesis imperfecta (OI), a rare disorder marked by bone fragility. Although aortic valve phenotypes, including BAV, have been described in OI, COL1 genes have not been implicated in sporadic BAV. We report rare COL1 variants in individuals with early-onset BAV (EBAV) complications. Whole-exome sequencing was performed in 272 non-syndromic BAV probands who developed valve or aortic complications before age 30 (EBAV) and 272 biological relatives. Variants were filtered by allele frequency, inheritance pattern, ClinVar classification, and in silico predictions. Participants with rare predicted damaging COL1 variants were recontacted to confirm phenotypes. Rare coding variants in COL1A1 (n = 5) and COL1A2 (n = 5) were identified in 10 (4%) EBAV probands, representing a 30-fold enrichment compared with European ancestry populations. Only two variants involved glycine substitutions in triple-helical domains. Affected probands presented with aortic regurgitation and/or thoracic aneurysms requiring repair and exhibited subtle connective tissue features such as joint hypermobility, recurrent fractures, or dental abnormalities. Predicted damaging COL1 variants are enriched in EBAV probands with features overlapping OI and Ehlers-Danlos syndrome, though involving different residues than those in OI. Genetic testing for these variants may help identify individuals who could benefit from personalized surveillance or targeted preventive strategies.

Microdeletions impacting 15q11.2 breakpoint (BP) 1 to BP2, adjacent to the Prader-Willi critical region, have previously described neuropsychiatric associations, with potential low penetrance presentations of congenital heart disease (CHD) also identified. Four highly conserved genes in the region (NIPA1, NIPA2, CYFIP1, and TUBGCP5) have been proposed to be involved in cardiac development, yet further exploration is needed to better define cardiac phenotypes of patients with copy number variants (CNVs) in the 15q11.2 BP1-BP2 region. This study examines cardiac defects in 50 patients with microdeletion (n = 37) or microduplication (n = 13) in 15q11.2 BP1-BP2, utilizing data from the Cytogenomics of Cardiovascular Malformations (CCVM) Consortium registry, composed of patients with both abnormal echocardiogram and chromosomal microarray findings. The microdeletion was found to be enriched in the registry compared to prevalence in a control population (OR = 3.9; p < 0.0001), with a significant increase of total anomalous pulmonary venous return (TAPVR) in patients who were carriers of the microdeletion (OR = 13.0; p < 0.0001). Left ventricular outflow tract obstruction (LVOTO) was increased in individuals with the microduplication (OR = 3.9; p = 0.02). Our results provide evidence for association of CHD with 15q11.2 BP1-BP2 CNVs, with novel associations reported.

PURPOSE:To replace an existing clinical practice guideline for the diagnosis and management of phenylalanine hydroxylase (PAH) deficiency. METHODS:The PAH Deficiency Guideline Workgroup used the Grading of Recommendations Assessment, Development, and Evaluation evidence-to-decision framework to develop evidence summaries and practice recommendations based on the recent American College of Medical Genetics and Genomics systematic review. RESULTS:Many recommendations from the 2014 PAH practice guideline are recognized as standard of care in this evidence-based guideline. Key recommendations from the previous guideline that were not supported by strong evidence are now strongly supported; (1) treatment for PAH deficiency should be lifelong for individuals with untreated phenylalanine (Phe) levels >360 μmol/L, (2) individuals with lifelong Phe levels ≤360 μmol/L have better intellectual outcomes than those who do not, (3) achieving Phe levels ≤360 μmol/L before conception is strongly recommended to prevent pregnancy complications and negative outcomes for the offspring, and (4) genetic testing for PAH variants is recommended at birth to confirm diagnosis and guide therapy. CONCLUSION:We strongly recommend lifelong maintenance of Phe ≤360 μmol/L (using plasma or whole blood) for optimal intellectual outcomes and for reduced teratogenicity, utilizing all available and necessary dietary, pharmaceutical, and patient-educational modalities.

BACKGROUND:Survivors of hypoplastic left heart syndrome (HLHS), the most severe form of congenital heart disease, are at high risk for heart failure (HF). HF in early life is a major contributor to mortality in this vulnerable population. However, reliable approaches to identify infants at highest risk for early HF are currently lacking. OBJECTIVES:The purpose of this study was to evaluate whether ultra-rare variants in cardiomyopathy-associated genes are associated with HF risk in HLHS. METHODS:Neonates with HLHS were prospectively enrolled within the first 21 days of life at Duke University Health System. Children and adults with HLHS who were older than 21 days were enrolled from Duke University Health System and the University of North Carolina into an ambispective cohort. External HLHS cohorts from Nationwide Children's Hospital and Vanderbilt University Medical Center were evaluated to assess for reproducibility across institutions. Participants underwent genome sequencing, and ultra-rare variants in dilated cardiomyopathy-associated genes (minor allele frequency ≤0.01%) were evaluated. The primary outcome was HF, categorized as severe (ventricular assist device implantation, heart transplantation, or death) or medically managed (reduced systemic ventricular ejection fraction and/or HF diagnosis requiring initiation or escalation of HF therapy). Associations between variant status and HF risk were assessed using Cox regression. RESULTS:Among 35 neonates in the prospective cohort, 7 (20.0%) developed severe HF, 10 (28.6%) developed medically managed HF, and 18 (51.4%) remained HF free. The presence of a likely pathogenic/pathogenic variant was associated with a marked 9-fold increased risk of severe HF compared with genotype-negative individuals (P = 0.02). Most severe HF events occurred within the first month of life (67%). Similar associations between likely pathogenic/pathogenic variants and severe HF were observed in the Nationwide Children's Hospital and Vanderbilt University Medical Center cohorts (11- and 3-fold increased risk, respectively; all P < 0.05). Associations were attenuated in the ambispective cohort (all P > 0.05), which consisted of individuals significantly older than the prospective cohort (P < 0.0001). CONCLUSIONS:This study provides the first prospective evidence linking dilated cardiomyopathy-associated variants to early-onset HF in HLHS. These findings suggest that genetic variation may contribute to myocardial vulnerability in HLHS, highlighting the potential for genetic screening to enable early risk stratification and guide precision medicine approaches in this high-risk population.

Background Bicuspid aortic valve (BAV) is the most common congenital heart defect in adults, often leading to complications such as thoracic aortic aneurysms and aortic stenosis. While BAV is frequently associated with 22q11.2 deletion syndrome (22q11.2DS), the contribution of rare copy number variants (CNVs) in this region to non-syndromic BAV is less clear. This study is aimed to assess the role of rare 22q11.2 CNVs in patients with early-onset BAV (EBAV) and to determine whether these variants are linked to an increased risk of complications.Methods Whole genome microarray genotyping was conducted on 272 patients with BAV with early onset valve or aortic disease (EBAV) and 272 biological relatives. CNVs were detected using three independent algorithms, focusing on the 22q11.2 region (18-24 Mb). CNV burden in the EBAV cohort was compared with unselected European ancestry controls.Results Rare duplications and deletions within the 22q11.2 region, particularly involving genes associated with cardiac development, were identified in 7.4% of EBAV probands. These CNVs were significantly enriched compared with the general population and segregated with BAV in families. Individuals carrying rare 22q11.2 CNVs had a higher prevalence of psychiatric diagnoses and learning difficulties, although they did not exhibit the typical features of 22q11.2DS. Importantly, these CNVs were associated with early onset or complex BAV cases, underscoring their potential clinical relevance.Conclusions Rare 22q11.2 CNVs play a role in non-syndromic BAV, particularly in cases with early onset or complex presentations. CNV screening could be considered as part of risk stratification for patients with BAV, helping to predict complications and guide management.Trial registration number NCT01823432.

BACKGROUND:Copy number variants (CNVs) contribute to 3% to 10% of isolated congenital heart disease (CHD) cases, yet their pathogenic roles remain unclear. Diagnostic efforts have focused on protein-coding genes, largely overlooking long noncoding RNAs (lncRNAs), which play key roles in development and disease. METHODS AND RESULTS:We systematically analyzed lncRNAs overlapping clinically validated CNVs in 743 patients with CHD from the Cytogenomics of Cardiovascular Malformations Consortium. We identified heart-expressed lncRNAs, constructed a gene regulatory network using weighted gene coexpression network analysis, and identified gene modules associated with heart development. Functional enrichment and network analyses were used to identify lncRNAs that may be involved in heart development and potentially contribute to CHD. The code is stably archived at https://doi.org/10.5281/zenodo.13799779. We identified 18 lncRNA candidate genes within modules significantly correlated with heart tissue, highlighting their potential involvement in CHD pathogenesis. Notably, lncRNAs such as lnc-STK32C-3, lnc-TBX20-1, and CRMA demonstrated strong associations with known CHD genes. Strikingly, although only 7.6% of known CHD genes were affected by a CNV, 68.8% of the CNVs contained a lncRNA expressed in the heart. CONCLUSIONS:Using weighted gene coexpression network analysis, we identified CNV-associated lncRNAs with potential relevance to CHD, underscoring the complexities of noncoding regions in disease pathogenesis. These findings suggest that lncRNAs may play a greater role in CHD than previously recognized, highlighting the need for broader genomic analyses that extend beyond protein-coding genes. This study provides a foundation for further exploration of lncRNAs in CHD, with potential implications for improved genetic characterization and diagnosis.

Introduction5p deletion syndrome, also called Cri-du-chat syndrome 5p is a rare genetic syndrome with reports up to 36% of patients are associated with congenital heart defects. We investigated the association between left outflow tract obstruction and Cri-du-chat syndrome.MethodsA retrospective review of the abnormal microarray cases with congenital heart defects in Children’s Hospital of Pittsburgh and the Cytogenomics of Cardiovascular Malformations Consortium.ResultsA retrospective review at nine pediatric centers identified 4 patients with 5p deletions and left outflow tract obstruction (LVOTO). Three of these patients had additional copy number variants. We present data suggesting an association of LVOTO with 5p deletion with high mortality in the presence of additional copy number variants.ConclusionA rare combination of 5p deletion and left ventricular outflow obstruction was observed in the registry of copy number variants and congenital heart defects.

Bicuspid aortic valve (BAV) is the most common congenital heart malformation in adults, but it can also cause childhood-onset complications. The presentation and clinical course of young adults who present due to BAV complications are relatively uncharacterized. In a multicenter study, we found that young people who experience significant complications related to BAV disease before age 30 are distinguished from the majority of BAV cases that manifest after age 50 by a relatively severe clinical course, with higher rates of surgical interventions, more frequent second interventions, and a greater burden of congenital heart malformations. These observations highlight the need for prompt recognition, regular lifelong surveillance, and targeted interventions to address the significant health burdens of patients with early-onset BAV complications.

Background: Copy Number Variants (CNVs) contribute to 3-10% of isolated Congenital Heart Disease (CHD) cases, but their roles in disease pathogenesis are often unclear. Traditionally, diagnostics have focused on protein-coding genes, overlooking the pathogenic potential of non-coding regions constituting 99% of the genome. Long non-coding RNAs (lncRNAs) are increasingly recognized for their roles in development and disease. Methods: In this study, we systematically analyzed candidate lncRNAs overlapping with clinically validated CNVs in 1,363 CHD patients from the Cytogenomics of Cardiovascular Malformations (CCVM) Consortium. We identified heart-expressed lncRNAs, constructed a gene regulatory network using Weighted Gene Co-expression Network Analysis (WGCNA), and identified gene modules significantly associated with heart development. Functional enrichment analyses and network visualizations were conducted to elucidate the roles of these lncRNAs in cardiac development and disease. The code is stably archived at https://doi.org/10.5281/zenodo.13799847. Results: We identified 18 lncRNA candidate genes within modules significantly correlated with heart tissue, highlighting their potential involvement in CHD pathogenesis. Notably, lncRNAs such as lnc-STK32C-3, lnc-TBX20-1, and CRMA demonstrated strong associations with known CHD genes. Strikingly, while only 7.6% of known CHD genes were impacted by a CNV, 68.8% of the CNVs contained a lncRNA expressed in the heart. Conclusions: Our findings highlight the critical yet underexplored role of lncRNAs in the genomics of CHD. By investigating CNV-associated lncRNAs, this study paves the way for deeper insights into the genetic basis of CHD by incorporating non-coding genomic regions. The research underscores the need for advanced annotation techniques and broader genetic database inclusion to fully capture the potential of lncRNAs in disease mechanisms. Overall, this work emphasizes the importance of the non-coding genome as a pivotal factor in CHD pathogenesis, potentially uncovering novel contributors to disease risk. ### Competing Interest Statement The authors have declared no competing interest.

Bicuspid aortic valve (BAV), the most common congenital heart defect, is a major cause of aortic valve disease requiring valve interventions and thoracic aortic aneurysms predisposing to acute aortic dissections. The spectrum of BAV ranges from early onset valve and aortic complications (EBAV) to sporadic late onset disease. Rare genomic copy number variants (CNVs) have previously been implicated in the development of BAV and thoracic aortic aneurysms. We determined the frequency and gene content of rare CNVs in EBAV probands (n = 272) using genome-wide SNP microarray analysis and three complementary CNV detection algorithms (cnvPartition, PennCNV, and QuantiSNP). Unselected control genotypes from the Database of Genotypes and Phenotypes were analyzed using identical methods. We filtered the data to select large genic CNVs that were detected by multiple algorithms. Findings were replicated in a BAV cohort with late onset sporadic disease (n = 5040). We identified 3 large and rare (< 1,1000 in controls) CNVs in EBAV probands. The burden of CNVs intersecting with genes known to cause BAV when mutated was increased in case-control analysis. CNVs intersecting with GATA4 and DSCAM were enriched in cases, recurrent in other datasets, and segregated with disease in families. In total, we identified potentially pathogenic CNVs in 9% of EBAV cases, implicating alterations of candidate genes at these loci in the pathogenesis of BAV.

Vascular Ehlers-Danlos, Marfan and Loeys-Dietz syndromes have increased risk of aortic dilation and dissection. Previous early studies showed hypermobile Ehlers-Danlos syndrome (hEDS) may also have increased risk, with echocardiography screening recommended; subsequent studies have not confirmed the risk or recommended echocardiography. This pediatric-based study assessed aortic dilation prevalence in those with hEDS by serial echocardiographic examinations and assessed family history for aortic dissections. We retrospectively identified individuals with hEDS who had echocardiography studies from the electronic medical records at one pediatric center. Aortic root Z-scores >2.0 were found in 15/225 subjects (average age 12.9 years) on initial echocardiograms, with no Z-score >3.0. Subsequent studies (n = 68) found statistically significant decline in aortic root Z-scores. Repeat echocardiography in those with initial aortic root Z-score >2.0 (n = 10) demonstrated a decline in Z score <2.0 in seven. On final examination, 9/225 (4.0%) had a Z-score >2.0, not statistically different from the general population. No aortic dissection occurred in first- or second-degree relatives. In conclusion, aortic root dilation rate in hEDS is likely not different from the general population. We propose that in the absence of other cardiac findings or suspicion for another disorder, echocardiography is not required in hEDS.

The genes EIF3A (HGNC:3271) and EIF3B (HGNC:3280) encode individual subunits constituting the eukaryotic initiation factor 3 (eIF3) complex, a pivotal regulator of protein synthesis. Their interaction forms the nucleation core of the eIF3 complex, a crucial stage in its assembly. Reports have identified interstitial and terminal deletions on chromosome 7p22.3 in patients exhibiting a variable phenotype, encompassing neurodevelopmental delay, distinct facial features, and congenital heart defects (CHD), notably tetralogy of Fallot (TOF).

CELSR3 codes for a planar cell polarity protein. We describe twelve affected individuals from eleven independent families with bi-allelic variants in CELSR3. Affected individuals presented with an overlapping phenotypic spectrum comprising central nervous system (CNS) anomalies (7/12), combined CNS anomalies and congenital anomalies of the kidneys and urinary tract (CAKUT) (3/12) and CAKUT only (2/12). Computational simulation of the 3D protein structure suggests the position of the identified variants to be implicated in penetrance and phenotype expression. CELSR3 immunolocalization in human embryonic urinary tract and transient suppression and rescue experiments of Celsr3 in fluorescent zebrafish reporter lines further support an embryonic role of CELSR3 in CNS and urinary tract formation.

Background Pathogenic GATA6 variants have been associated with congenital heart disease (CHD) and a spectrum of extracardiac abnormalities, including pancreatic agenesis, congenital diaphragmatic hernia, and developmental delay. However, the comprehensive genotype-phenotype correlation of pathogenic GATA6 variation in humans remains to be fully understood. Methods Exome sequencing was performed in a family where four members had CHD. In vitro functional analysis of the GATA6 variant was performed using immunofluorescence, western blot, and dual-luciferase reporter assay. Results A novel, heterozygous missense variant in GATA6 (c.1403 G > A; p.Cys468Tyr) segregated with affected members in a family with CHD, including three with persistent truncus arteriosus. In addition, one member had childhood onset diabetes mellitus (DM), and another had necrotizing enterocolitis (NEC) with intestinal perforation. The p.Cys468Tyr variant was located in the c-terminal zinc finger domain encoded by exon 4. The mutant protein demonstrated an abnormal nuclear localization pattern with protein aggregation and decreased transcriptional activity. Conclusions We report a novel, familial GATA6 likely pathogenic variant associated with CHD, DM, and NEC with intestinal perforation. These findings expand the phenotypic spectrum of pathologic GATA6 variation to include intestinal abnormalities. Impact Exome sequencing identified a novel heterozygous GATA6 variant (p.Cys468Tyr) that segregated in a family with CHD including persistent truncus arteriosus, atrial septal defects and bicuspid aortic valve. Additionally, affected members displayed extracardiac findings including childhood-onset diabetes mellitus, and uniquely, necrotizing enterocolitis with intestinal perforation in the first four days of life. In vitro functional assays demonstrated that GATA6 p.Cys468Tyr variant leads to cellular localization defects and decreased transactivation activity. This work supports the importance of GATA6 as a causative gene for CHD and expands the phenotypic spectrum of pathogenic GATA6 variation, highlighting neonatal intestinal perforation as a novel extracardiac phenotype.

Purpose For patients with congenital heart disease (CHD), the most common birth defect, genetic evaluation is not universally accepted, and current practices are anecdotal. Here, we analyzed genetic evaluation practices across centers, determined diagnostic yield of testing, and identified phenotypic features associated with abnormal results. Methods This is a multicenter cross-sectional study of 5 large children's hospitals, including 2899 children ≤14 months undergoing surgical repair for CHD from 2013 to 2016, followed by multivariate logistics regression analysis. Results Genetic testing occurred in 1607 of 2899 patients (55%). Testing rates differed highly between institutions (42%-78%, P < .001). Choice of testing modality also differed across institutions (ie, chromosomal microarray, 26%-67%, P < .001). Genetic testing was abnormal in 702 of 1607 patients (44%), and no major phenotypic feature drove diagnostic yield. Only 849 patients were seen by geneticists (29%), ranging across centers (15%-52%, P < .001). Geneticist consultation associated with increased genetic testing yield (odds ratio: 5.7, 95% CI 4.33-7.58, P < .001). Conclusion Genetics evaluation in CHD is diagnostically important but underused and highly variable, with high diagnostic rates across patient types, including in infants with presumed isolated CHD. These findings support recommendations for comprehensive testing and standardization of care.