Risk of congenital heart disease in relatives of probands with conotruncal cardiac defects: an evaluation of 1,620 families

Pregnancy in women with congenital heart disease: New insights into neonatal risk prediction

BACKGROUND

Advances in managing adult congenital heart disease (ACHD) have led to an increased number of women with CHD reaching childbearing age. This demographic shift underscores the need for improved understanding and prediction of complications during pregnancy in this specific ACHD population. Despite progress in maternal cardiac risk assessment, the prediction of neonatal outcomes for ACHD pregnancies remains underdeveloped. Therefore, the aims of this study are to assess neonatal outcomes in a CHD women population, to identify their predictive factors and to propose a new risk score for predicting neonatal complications.

METHODS

This registry study included all women born between 1975 and 1996 diagnosed with ACHD who underwent at least one cardiology consultation for ACHD in Cliniques Universitaires Saint-Luc. A multivariate analysis was performed to identify predictors of neonatal complications and these were incorporated into a new risk index. Its validity was assessed using bootstrap method. This score was then compared with scores adapted from the ZAHARA and CARPREG studies for offspring events prediction.

RESULTS

Analysis of 491 pregnancies revealed 31.4% of neonatal complications. Four significant predictors of adverse neonatal outcomes were identified: cardiac treatment during pregnancy (OR 14.8, 95%CI [3.4-66]), hypertensive disorders of pregnancy (OR 11.4, 95%CI [3.4-39.0]), smoking during pregnancy (OR 10.6, 95%CI [2.8-40.6]), and pre-pregnancy BMI <18.5 kg/m² (OR 6.5, 95%CI [2.5-16.5]). The risk model demonstrated an AUC of 0.70 (95%CI [0.65-0.75]), which remained stable after bootstrap validation. This model significantly outperformed the scores adapted from ZAHARA and CARPREG data. Based on the regression coefficients, a risk score was subsequently developed comprising five risk categories.

CONCLUSIONS

One third of ACHD pregnancies are complicated by poor neonatal outcome. These complications are determined by four independent factors relating to the cardiac and non-cardiac status of the patients, which have been incorporated into a risk score. Our study is one of the first to propose a predictive risk score of neonatal outcomes in ACHD pregancies, and paves the way for other validation and confirmation studies.

Human Genetics of Congenital Heart Defects

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

Triple repeated fetal congenital heart disease linked to PLD1 mutation: a case report

BACKGROUND

Congenital heart disease occurs in approximately 1 in 100 cases. Although sibling occurrence is high (3-9%), the causative genes for this disease are still being elucidated. PLD1 (Phospholipase D1) is a recently discovered gene; however, few case reports have been published on it. In this report, we describe a case of triplicate fetal congenital heart disease that was diagnosed as a PDL1 mutation. Our objective is to explore the clinical manifestations of PLD1 mutations in this particular case.

CASE PRESENTATION

A 32-year-old Japanese woman (gravida, para 0) was introduced since fetus four chamber view was not clear and was diagnosed with ductus arteriosus-dependent left ventricular single ventricle and pulmonary atresia at 21 weeks and 1 day of gestation during her first pregnancy. Artificial abortion using Gemeprost was performed at 21 weeks and 5 days of gestation. The second pregnancy was diagnosed as pulmonary atresia with intact ventricular septum with cardiomegaly, a cardiothoracic area ratio of more than 35%, and a circulatory shunt at 13 weeks and 3 days of gestation. Subsequently, intrauterine fetal death was confirmed at 14 weeks and 3 days of gestation. Regarding the third pregnancy, fetal ultrasonography at 11 weeks and 5 days of gestation showed mild fetal hydrops and moderate tricuspid valve regurgitation. At 16 weeks and 5 days of gestation, the fetus was suspected to have a left ventricular-type single ventricle, trace right ventricle, pulmonary atresia with intact ventricular septum, or cardiomyopathy. Cardiac function gradually declined at 26 weeks of gestation, and intrauterine fetal death was confirmed at 27 weeks and 5 days of gestation. The fourth pregnancy resulted in a normal heart with good progression and no abnormal baby. We submitted the first and second fetuses' umbilical cord, third fetus' placenta, and the fourth fetus' blood to genetic testing using whole exome analysis with next generation sequencing. Genetic analysis identified hemizygous PLD1 mutations in the first, second, and third fetuses. The fourth fetus was heterozygous. In addition, the parents were heterozygous for PLD1. This case is based on three consecutive cases of homozygosity for the PLD1 gene in the sibling cases and the fetuses with recurrent right ventricular valve dysplasia. This will elucidate the cause of recurrent congenital heart disease and intrauterine fetal death and may serve as an indicator for screening the next fetus. To date, homozygous mutations in PLD1 that repeat three times in a row are not reported, only up to two times. The novelty of this report is that it was repeated three times, followed by a heterozygous live birth.

CONCLUSIONS

This report is consistent with previous reports that mutations in PLD1 cause right ventricular valve dysplasia. However, there have been few case reports of PLD1 mutations, and we hope that this report will contribute to elucidate the causes of congenital heart disease, especially right ventricular valve dysplasia, and that the accumulation of such information will provide more detailed information on PLD1 mutations in heart disease.

Recurrence pattern of non-syndromic familial congenital heart diseases among a large cohort of families from Egypt

Background

Congenital heart diseases (CHD) are the commonest congenital anomalies with increased risk in children born from families with affected members. However, various recurrence patterns of CHDs have been reported in different populations. Therefore, this work aimed to assess the recurrence patterns of CHDs in a large sample of Egyptian families.

Methods

From January 2020 to October 2021, non-syndromic children with confirmed CHDs were recruited. Data were collected from guardians of the recruited children and hospital records, including the index case’s cardiac diagnosis and CHD diagnosis of other affected family members with to determine their recurrence pattern, consanguinity, and multi-gestation status.

Results

A total of 130 recurrent cases with CHD were documented in 1960 families of children with CHD, including 66,989 members. Most recurrences were detected among first-degree relatives 50/130 (38.46%), especially siblings. Discordant recurrence was the most detected pattern (45.38%), followed by concordant recurrence (42.31%), and the least was group concordance. Recurrence rate was the highest for septal defects with left ventricular outflow tract obstruction (LVOTO) (11.8%) and anomalous venous drainage (11.1%), followed by septal defect with right ventricular outflow tract obstruction (RVOTO) (9.4%), isolated ventricular septal defect (VSD) category (8.2%) and LVOTO (8%). Familial recurrence was significant in consanguineous marriages [p = 0.0001; OR (95%CI) = 4.5 (2.25–9.01)] and in multi-gestations siblings: [p = 0.036; OR (95%CI) = 12.5(1.03–6.04)].

Conclusion

The recurrence of non-syndromic CHD is evident among first-degree relatives in Egyptian families, with mostly a discordant recurrence pattern. Recurrence was more notable in septal defects with LVOTO, anomalous venous drainage, septal defect with RVOTO, isolated VSD, and isolated LVOTO diagnostic categories. This finding will significantly impact family counseling, emphasizing higher recurrence in consanguineous parents.

Supplementary information

The online version contains supplementary material available at 10.1186/s12887-022-03640-4.

Familial Recurrence Patterns in Congenitally Corrected Transposition of the Great Arteries: An International Study

BACKGROUND

Congenitally corrected transposition of the great arteries (ccTGA) is a rare disease of unknown cause. We aimed to better understand familial recurrence patterns.

METHODS

An international, multicentre, retrospective cohort study was conducted in 29 tertiary hospitals in 6 countries between 1990 and 2018, entailing investigation of 1043 unrelated ccTGA probands.

RESULTS

Laterality defects and atrioventricular block at diagnosis were observed in 29.9% and 9.3%, respectively. ccTGA was associated with primary ciliary dyskinesia in 11 patients. Parental consanguinity was noted in 3.4% cases. A congenital heart defect was diagnosed in 81 relatives from 69 families, 58% of them being first-degree relatives, including 28 siblings. The most prevalent defects in relatives were dextro-transposition of the great arteries (28.4%), laterality defects (13.6%), and ccTGA (11.1%); 36 new familial clusters were described, including 8 pedigrees with concordant familial aggregation of ccTGA, 19 pedigrees with familial co-segregation of ccTGA and dextro-transposition of the great arteries, and 9 familial co-segregation of ccTGA and laterality defects. In one family co-segregation of ccTGA, dextro-transposition of the great arteries and heterotaxy syndrome in 3 distinct relatives was found. In another family, twins both displayed ccTGA and primary ciliary dyskinesia.

CONCLUSIONS

ccTGA is not always a sporadic congenital heart defect. Familial clusters as well as evidence of an association between ccTGA, dextro-transposition of the great arteries, laterality defects and in some cases primary ciliary dyskinesia, strongly suggest a common pathogenetic pathway involving laterality genes in the pathophysiology of ccTGA.

22q11.2 Deletion Syndrome: Impact of Genetics in the Treatment of Conotruncal Heart Defects

Congenital heart diseases represent one of the hallmarks of 22q11.2 deletion syndrome. In particular, conotruncal heart defects are the most frequent cardiac malformations and are often associated with other specific additional cardiovascular anomalies. These findings, together with extracardiac manifestations, may affect perioperative management and influence clinical and surgical outcome. Over the past decades, advances in genetic and clinical diagnosis and surgical treatment have led to increased survival of these patients and to progressive improvements in postoperative outcome. Several studies have investigated long-term follow-up and results of cardiac surgery in this syndrome. The aim of our review is to examine the current literature data regarding cardiac outcome and surgical prognosis of patients with 22q11.2 deletion syndrome. We thoroughly evaluate the most frequent conotruncal heart defects associated with this syndrome, such as tetralogy of Fallot, pulmonary atresia with major aortopulmonary collateral arteries, aortic arch interruption, and truncus arteriosus, highlighting the impact of genetic aspects, comorbidities, and anatomical features on cardiac surgical treatment.

Whole genome sequencing in transposition of the great arteries and associations with clinically relevant heart, brain and laterality genes

BACKGROUND

The most common cyanotic congenital heart disease (CHD) requiring management as a neonate is transposition of great arteries (TGA). Clinically, up to 50% of TGA patients develop some form of neurodevelopmental disability (NDD), thought to have a significant genetic component. A "ciliopathy" and links with laterality disorders have been proposed. This first report of whole genome sequencing in TGA, sought to identify clinically relevant variants contributing to heart, brain and laterality defects.

METHODS

Initial whole genome sequencing analyses on 100 TGA patients focussed on established disease genes related to CHD (n = 107), NDD (n = 659) and heterotaxy (n = 74). Single variant as well as copy number variant analyses were conducted. Variant pathogenicity was assessed using the American College of Medical Genetics and Genomics-Association for Molecular Pathology guidelines.

RESULTS

Fifty-five putatively damaging variants were identified in established disease genes associated with CHD, NDD and heterotaxy; however, no clinically relevant variants could be attributed to disease. Notably, case-control analyses identified significantly more predicted-damaging, silent and total variants in TGA cases than healthy controls in established CHD genes (P < .001), NDD genes (P < .001) as well as across the three gene panels (P < .001).

CONCLUSION

We present compelling evidence that the majority of TGA is not caused by monogenic rare variants and is most likely oligogenic and/or polygenic in nature, highlighting the complex genetic architecture and multifactorial influences on this CHD sub-type and its long-term sequelae. Assessment of variant burden in key heart, brain and/or laterality genes may be required to unravel the genetic contributions to TGA and related disabilities.

Common Genetic Variants Contribute to Risk of Transposition of the Great Arteries

RATIONALE

Dextro-transposition of the great arteries (D-TGA) is a severe congenital heart defect which affects approximately 1 in 4,000 live births. While there are several reports of D-TGA patients with rare variants in individual genes, the majority of D-TGA cases remain genetically elusive. Familial recurrence patterns and the observation that most cases with D-TGA are sporadic suggest a polygenic inheritance for the disorder, yet this remains unexplored.

OBJECTIVE

We sought to study the role of common single nucleotide polymorphisms (SNPs) in risk for D-TGA.

METHODS AND RESULTS

We conducted a genome-wide association study in an international set of 1,237 patients with D-TGA and identified a genome-wide significant susceptibility locus on chromosome 3p14.3, which was subsequently replicated in an independent case-control set (rs56219800, meta-analysis P=8.6x10-10, OR=0.69 per C allele). SNP-based heritability analysis showed that 25% of variance in susceptibility to D-TGA may be explained by common variants. A genome-wide polygenic risk score derived from the discovery set was significantly associated to D-TGA in the replication set (P=4x10-5). The genome-wide significant locus (3p14.3) co-localizes with a putative regulatory element that interacts with the promoter of WNT5A, which encodes the Wnt Family Member 5A protein known for its role in cardiac development in mice. We show that this element drives reporter gene activity in the developing heart of mice and zebrafish and is bound by the developmental transcription factor TBX20. We further demonstrate that TBX20 attenuates Wnt5a expression levels in the developing mouse heart.

CONCLUSIONS

This work provides support for a polygenic architecture in D-TGA and identifies a susceptibility locus on chromosome 3p14.3 near WNT5A. Genomic and functional data support a causal role of WNT5A at the locus.

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.

Rare variants in KDR, encoding VEGF Receptor 2, are associated with tetralogy of Fallot

PURPOSE

Rare genetic variants in KDR, encoding the vascular endothelial growth factor receptor 2 (VEGFR2), have been reported in patients with tetralogy of Fallot (TOF). However, their role in disease causality and pathogenesis remains unclear.

METHODS

We conducted exome sequencing in a familial case of TOF and large-scale genetic studies, including burden testing, in >1,500 patients with TOF. We studied gene-targeted mice and conducted cell-based assays to explore the role of KDR genetic variation in the etiology of TOF.

RESULTS

Exome sequencing in a family with two siblings affected by TOF revealed biallelic missense variants in KDR. Studies in knock-in mice and in HEK 293T cells identified embryonic lethality for one variant when occurring in the homozygous state, and a significantly reduced VEGFR2 phosphorylation for both variants. Rare variant burden analysis conducted in a set of 1,569 patients of European descent with TOF identified a 46-fold enrichment of protein-truncating variants (PTVs) in TOF cases compared to controls (P = 7 × 10-11).

CONCLUSION

Rare KDR variants, in particular PTVs, strongly associate with TOF, likely in the setting of different inheritance patterns. Supported by genetic and in vivo and in vitro functional analysis, we propose loss-of-function of VEGFR2 as one of the mechanisms involved in the pathogenesis of TOF.

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.

Genetics in congenital heart disease. Are we ready for it?

Genetics has rightly acquired an important place in almost all medical disciplines in recent years and this is certainly the case in the field of congenital cardiology. Not only has this led to greater insight into the pathophysiology of congenital heart defects but it also has a beneficial impact on patient management. Integration of clinical genetics in multidisciplinary centers of expertise for CHD is therefore a clear recommendation. Adult and pediatric cardiologists play a crucial role in the process of genetic evaluation of patients and families and should have be familiar with red flags for referral for further clinical genetic elaboration, counseling, and eventual testing. Some basic knowledge is also important for the correct interpretation of genetic testing results. In this review article, we provide a practical overview of what genetic evaluation entails, which type of genetic tests are possible today, and how this can be used in practice for the individual patient.

22q11.2 Deletion Status Influences Resource Utilization in Infants Requiring Repair of Tetralogy of Fallot and Common Arterial Trunk

22q11.2 deletion syndrome leads to both cardiac and non-cardiac developmental defects. We aimed to study the impact of 22q11.2 deletion syndrome on in-hospital outcomes in children undergoing surgical repair for tetralogy of Fallot (TOF) and truncus arteriosus (TA). Using the nationally representative Kids Inpatient Database (KID), we analyzed data from in-hospital pediatric patients for the years 2003, 2006, 2009, and 2012. We compared the in-hospital outcomes between those with and those without 22q11.2 deletion syndrome. There were 6126 cases of TOF and 968 cases of TA. 22q11.2 deletion syndrome were documented in 7.2% (n = 441) of the TOF and 27.4% (n  =  265) of the TA group. 22q11.2 deletion did not significantly increase the risk of mortality in either group: [OR = 1.98 (95% CI 0.99-3.94), adjusted p  =  0.053] for TOF and OR = 1.07 (95% CI 0.57-1.99), adjusted p = 0.82 for TA. However, the length of hospitalization was longer in the 22q11.2 deletion group by 8.6 days (95% CI 5.2-12), adjusted p < 0.001 for TOF and by 8.15 days (95% CI 1.05-15.25), adjusted p = 0.025 for the TA group. Acute respiratory failure [10.6% vs 5.5%, p < 0.001] and acute renal failure [6.3% vs 2.6%, p < 0.001] were higher in 22q11.2 deletion cohort within the TOF group but not in the TA group. Though survival is not affected, children with 22q11.2 deletion syndrome who undergo surgical repair for TOF and TA use significantly more hospital resources-specifically longer hospital stay and higher hospitalization cost-than those without 22q11.2 deletion syndrome. Prenatal or preoperative testing for 22q11deletion is indicated to make appropriate adjustments in parental, caregiver, and administrative expectations.

The Use of Sonography in a Mother and Fetus With Concordant Truncus Arteriosus

Reported pregnancies in women with repaired truncus arteriosus are rare. As a result of improved surgical techniques, more women with conotruncal defects are now reaching reproductive age. Multifactorial inheritance rather than single gene mutation is the causative agent of most congenital heart disease. The environment can play an important and varied role in direct transmission, particularly in incidences where genes predispose a defect. This may be one of the first reported cases discussing a pregnant mother with repaired truncus arteriosus and her fetus, prenatally diagnosed with a concordant truncal defect.

ACOG Practice Bulletin No. 212: Pregnancy and Heart Disease

Maternal heart disease has emerged as a major threat to safe motherhood and women's long-term cardiovascular health. In the United States, disease and dysfunction of the heart and vascular system as "cardiovascular disease" is now the leading cause of death in pregnant women and women in the postpartum period () accounting for 4.23 deaths per 100,000 live births, a rate almost twice that of the United Kingdom (). The most recent data indicate that cardiovascular diseases constitute 26.5% of U.S. pregnancy-related deaths (). Of further concern are the disparities in cardiovascular disease outcomes, with higher rates of morbidity and mortality among nonwhite and lower-income women. Contributing factors include barriers to prepregnancy cardiovascular disease assessment, missed opportunities to identify cardiovascular disease risk factors during prenatal care, gaps in high-risk intrapartum care, and delays in recognition of cardiovascular disease symptoms during the puerperium. The purpose of this document is to 1) describe the prevalence and effect of heart disease among pregnant and postpartum women; 2) provide guidance for early antepartum and postpartum risk factor identification and modification; 3) outline common cardiovascular disorders that cause morbidity and mortality during pregnancy and the puerperium; 4) describe recommendations for care for pregnant and postpartum women with preexisting or new-onset acquired heart disease; and 5) present a comprehensive interpregnancy care plan for women with heart disease.

Familial co-occurrence of congenital heart defects follows distinct patterns

Aims

Congenital heart defects (CHD) affect almost 1% of all live born children and the number of adults with CHD is increasing. In families where CHD has occurred previously, estimates of recurrence risk, and the type of recurring malformation are important for counselling and clinical decision-making, but the recurrence patterns in families are poorly understood. We aimed to determine recurrence patterns, by investigating the co-occurrences of CHD in 1163 families with known malformations, comprising 3080 individuals with clinically confirmed diagnosis.

Methods and results

We calculated rates of concordance and discordance for 41 specific types of malformations, observing a high variability in the rates of concordance and discordance. By calculating odds ratios for each of 1640 pairs of discordant lesions observed between affected family members, we were able to identify 178 pairs of malformations that co-occurred significantly more or less often than expected in families. The data show that distinct groups of cardiac malformations co-occur in families, suggesting influence from underlying developmental mechanisms. Analysis of human and mouse susceptibility genes showed that they were shared in 19% and 20% of pairs of co-occurring discordant malformations, respectively, but none of malformations that rarely co-occur, suggesting that a significant proportion of co-occurring lesions in families is caused by overlapping susceptibility genes.

Conclusion

Familial CHD follow specific patterns of recurrence, suggesting a strong influence from genetically regulated developmental mechanisms. Co-occurrence of malformations in families is caused by shared susceptibility genes.

Gene-based genome-wide association studies and meta-analyses of conotruncal heart defects

Conotruncal heart defects (CTDs) are among the most common and severe groups of congenital heart defects. Despite evidence of an inherited genetic contribution to CTDs, little is known about the specific genes that contribute to the development of CTDs. We performed gene-based genome-wide analyses using microarray-genotyped and imputed common and rare variants data from two large studies of CTDs in the United States. We performed two case-parent trio analyses (N = 640 and 317 trios), using an extension of the family-based multi-marker association test, and two case-control analyses (N = 482 and 406 patients and comparable numbers of controls), using a sequence kernel association test. We also undertook two meta-analyses to combine the results from the analyses that used the same approach (i.e. family-based or case-control). To our knowledge, these analyses are the first reported gene-based, genome-wide association studies of CTDs. Based on our findings, we propose eight CTD candidate genes (ARF5, EIF4E, KPNA1, MAP4K3, MBNL1, NCAPG, NDFUS1 and PSMG3). Four of these genes (ARF5, KPNA1, NDUFS1 and PSMG3) have not been previously associated with normal or abnormal heart development. In addition, our analyses provide additional evidence that genes involved in chromatin-modification and in ribonucleic acid splicing are associated with congenital heart defects.

The association of elevated maternal genetic risk scores for hypertension, type 2 diabetes and obesity and having a child with a congenital heart defect

Background

Maternal hypertension, type 2 diabetes (T2D) and obesity are associated with an increased risk of having offspring with conotruncal heart defects (CTDs). Prior studies have identified sets of single nucleotide polymorphisms (SNPs) that are associated with risk for each of these three adult phenotypes. We hypothesized that these same SNPs are associated with maternal risk of CTDs in offspring.

Methods and results

We evaluated the parents of children with a CTD ascertained from the Children’s Hospital of Philadelphia (n = 466) and by the Pediatric Cardiac Genomic Consortium (n = 255). We used a family-based design to assess the association between CTDs and the maternal genotype for individual hypertension, T2D, and obesity-related SNPs and found no association between CTDs and the maternal genotype for any individual SNP. In addition, we calculated genetic risk scores (GRS) for hypertension, T2D, and obesity using previously published GRS formulas. When comparing the GRS of mothers to fathers, there were no statistically significant differences in the mean for the combined GRS or the GRS for each individual condition. However, when we categorized the mothers and fathers of cases with CTDs as having high (>95^th percentile) or low (≤95^th percentile) scores, compared to fathers, mothers had almost two times the odds of having a high GRS for hypertension (OR 1.7, 95% CI 1.0, 2.8) and T2D (OR 1.8, 95% CI 1.1, 3.1).

Conclusions

Our results support a link between maternal genetic risk for hypertension/T2D and CTDs in their offspring. These associations might be independent of maternal phenotype at conception.

Recurrent Congenital Heart Diseases Among Neonates Born to Mothers with Congenital Heart Diseases

The frequency of newborns with congenital heart disease (CHD) is approximately 1% in the general population; however, the recurrence rate of CHD in mothers with CHD differs in ethnicity and reports. We therefore aimed to determine the prevalence of CHD among neonates born to mothers with CHD in our institute in Japan. We reviewed the medical charts of 803 neonates delivered by 529 women with CHD at the National Cerebral and Cardiovascular Center from 1982 to 2016. They included isolated ventricular septal defect (VSD,31.4%), isolated atrial septal defect (ASD, 23.3%), tetralogy of Fallot (TOF,10.6%). We defined CHD in neonates as being diagnosed within 1 month of birth. We estimated that the average rate of the CHD recurrence was 3.1%. The recurrence ratios in each maternal CHD were 8.6%, 7.1%, 6.2%, 4.8%, 3.6%, and 1.5% for PS, CoA, TOF, atrioventricular septal defect, VSD, and ASD, respectively. The rate of CHD in offsprings whose mothers have CHD was 3 times greater than that of mothers with healthy hearts. Almost half of neonates with CHD had the same phenotype as their mother in our series. Especially, PS and CoA were closely related to the type of maternal CHD.

Proteomics analysis indicated the protein expression pattern related to the development of fetal conotruncal defects

Abnormal development of embryonic conus arteriosus could lead to conotruncal defects in fetal heart, and increase the incidence of fetal congenital heart disease. Tetralogy of Fallot (TOF) is one of the most common forms of congenital heart disease. It may be helpful for us to solve this clinical problem through exploring the molecular mechanisms of development in embryonic congenital heart disease. Proteomics has attracted much attention in understanding the development of human diseases during the past decades. However, there is still little information about the relationship between protein expression pattern and TOF. In this study, we aimed to explore the potential linkage of proteomics and TOF development. Briefly, 121 differentially expressed proteins were identified from a TOF group, compared with a control group. The expression levels of 34 of these proteins were significantly different (>1.5 absolute fold change, p < 0.05) between the two groups. Gene ontology (GO) and pathway analysis showed that these proteins were mainly associated with carbon metabolism, biosynthesis of antibodies, positive regulation of transcription from RNA polymerase II promoter, nucleus, ATP binding, and so on. The ingenuity pathway analysis (IPA) results indicated that 435 of upstream regulators were identified of these differentially expressed proteins, which might be involved in the development of TOF. Data of string analysis showed the protein-protein interaction network among the differentially expressed proteins and regulators, which are related to TOF. In conclusion, our study explored the protein expression pattern of TOF, which might provide new insights into understanding the mechanism of TOF development and afford potential targets for TOF diagnosis and therapy.

Congenital heart diseases and cardiovascular abnormalities in 22q11.2 deletion syndrome: From well-established knowledge to new frontiers

Congenital heart diseases (CHDs) and cardiovascular abnormalities are one of the pillars of clinical diagnosis of 22q11.2 deletion syndrome (22q11.2DS) and still represent the main cause of mortality in the affected children. In the past 30 years, much progress has been made in describing the anatomical patterns of CHD, in improving their diagnosis, medical treatment, and surgical procedures for these conditions, as well as in understanding the underlying genetic and developmental mechanisms. However, further studies are still needed to better determine the true prevalence of CHDs in 22q11.2DS, including data from prenatal studies and on the adult population, to further clarify the genetic mechanisms behind the high variability of phenotypic expression of 22q11.2DS, and to fully understand the mechanism responsible for the increased postoperative morbidity and for the premature death of these patients. Moreover, the increased life expectancy of persons with 22q11.2DS allowed the expansion of the adult population that poses new challenges for clinicians such as acquired cardiovascular problems and complexity related to multisystemic comorbidity. In this review, we provide a comprehensive review of the existing literature about 22q11.2DS in order to summarize the knowledge gained in the past years of clinical experience and research, as well as to identify the remaining gaps in comprehension of this syndrome and the possible future research directions.

TBX1 loss-of-function mutation contributes to congenital conotruncal defects

Conotruncal defects (CTDs) account for ~30% of all types of congenital heart disease and contribute to increased morbidity and mortality rates. Increasing evidence suggests that genetic risk factors are involved in the pathogenesis of CTDs. Mutations in a number of genes, including the TBX1 gene that codes for a T-box transcription factor essential for normal cardiovascular development, may contribute to the development of CTD. CTDs are genetically heterogeneous and the genetic defects responsible for CTDs in the majority of patients remain unknown. The present study sequenced the coding regions and splicing junction boundaries of TBX1 in 136 patients with CTDs and 300 matched healthy individuals. The disease-causing potential of the identified TBX1 sequence variation was evaluated using MutationTaster, PolyPhen-2, SIFT and PROVEN software. The functional characteristics of the mutant TBX1 gene were defined using a dual-luciferase reporter assay system. A novel heterozygous TBX1 mutation, p.S233Y, was identified in a patient with transposition of the great arteries (TGA) and a ventricular septal defect. This mutation was absent in the 300 controls and altered the amino acid produced, serine, which is evolutionarily conserved across several species, and was predicted to be pathogenic in silico. Luciferase assays conducted in COS-7 cells demonstrated that the newly identified TBX1 mutation was associated with significantly diminished transcriptional activation of the ANF promoter compared with the wild-type TBX1. To the best of our knowledge, the present study is the first to associate a TBX1 loss-of-function mutation with enhanced susceptibility to TGA, which adds significant insight to the molecular mechanism of TGA.

The Impact of 22q11.2 Deletion Syndrome on Surgical Repair Outcomes of Conotruncal Cardiac Anomalies

BACKGROUND

We aim to describe the impact of 22q11.2 deletion syndrome (22q11DS) on clinical characteristics, postoperative course, and early and late outcomes of neonates undergoing surgery for conotruncal anomalies.

METHODS

A retrospective review was performed (2002 to 2012) of 224 neonates who underwent surgery for interrupted aortic arch (n = 67), truncus arteriosus (n = 85), or ductal-dependent pulmonary atresia and ventricular septal defect (n = 72). Patients were divided into three groups: group 1, n = 119, no genetic syndrome; group 2, n = 64, 22q11DS; and group 3, n = 41, other genetic syndrome. Adjusted analysis to compare outcomes was performed.

RESULTS

In comparison with group 1, group 2 had longer mechanical ventilation duration (148 versus 102 hours, p = 0.008), intensive care unit stay (268 versus 159 hours, p < 0.001), and hospital stay (19.3 versus 11.5 days, p < 0.001). On adjusted analysis, there was an insignificant increase in unplanned reoperation (odds ratio [OR] 2.4, 95% confidence interval [CI]: 0.7 to 8.4, p = 0.167) but no increased extracorporeal membrane oxygenation use (OR 1.5, 95% CI: 0.3 to 6.1, p = 0.612), hospital mortality (OR 0.6, 95% CI: 0.1 to 3.3, p = 0.570), or decreased late survival (hazard ratio 0.9, 95% CI: 0.4 to 2.1, p = 0.822). In comparison with group 1, group 3 had longer mechanical ventilation duration (190 versus 102 hours, p < 0.001), intensive care unit stay (236 versus 159 hours, p = 0.007), and hospital stay (21.5 versus 11.5 days, p < 0.001); and increased unplanned reoperation (OR 3.7, 95% CI: 1.1 to 12.5, p = 0.032), extracorporeal membrane oxygenation use (OR 4.4, 95% CI: 1.1 to 17.6, p = 0.038), hospital mortality (OR 4.2, 95% CI: 1.2 to 14.5, p = 0.021), and diminished late survival (hazard ratio 4.0, 95% CI: 2.1 to 8.1, p < 0.001).

CONCLUSIONS

In neonates with conotruncal anomalies, 22q11DS is associated with prolonged recovery and increased resource utilization. However, despite a small increase in unplanned reoperation, there is no significant impact on early or late survival. In comparison, other genetic syndromes are associated with increased unplanned reoperation, extracorporeal membrane oxygenation use, hospital mortality, and diminished late survival. These findings are important for family counseling and risk stratification.

Imaging the adult with transposition of the great arteries

PURPOSE OF REVIEW

Patients with complete and congenitally corrected transposition of the great arteries commonly survive into adulthood and present with a vast array of clinical residua.

RECENT FINDINGS

Echocardiography remains the primary imaging modality in the routine assessment of the adult with transposition of the great arteries. It provides a comprehensive anatomic and hemodynamic evaluation. Limitations to echocardiography include evaluation of the following: the systemic right ventricle, baffle patency following atrial switch procedure, coronary arteries following arterial switch procedure or Nikadoh, and multilevel right ventricular outflow tract obstruction.

SUMMARY

Each form of palliation for transposition of the great arteries results in unique long-term sequelae that affect outcomes. A multimodality approach to imaging is required for a complete evaluation.

Cancer risk in siblings of children with congenital malformations

PURPOSE

Cancer and birth defects cluster in families more often than expected by chance, but the reasons are neither well known nor well studied.

METHODS

From singletons born alive in Denmark between 1 January 1977 and 31 December 2007, we identified children who had no congenital malformations but had a full or half sibling with a congenital malformation (CM) diagnosed in the first year of life; this constituted the exposed group, while children whose siblings had no such condition constituted a reference group. We estimated cancer risks for children who had a full sibling or a half sibling with a CM using a Cox proportional hazards regression model. To control for confounding related to change of family structure, we estimated cancer risks for children from core families and children from broken families separately. Children were followed from birth up to 30 years of age (median follow-up 13.6 years). We obtained information on CMs and cancer from the Danish National Hospital Register and the Danish Cancer Registry.

RESULTS

We identified 991,454 (78%) children from core families with 53,995 children who had a full sibling with a CM and 277,773 (22%) children from broken families with 7200 children who had a full sibling with a CM and 6194 children who had a half sibling with a CM. Children who had a full sibling with a CM from both core and broken families showed, in general, no increased cancer risk compared with children whose siblings had no CM, except in the case of children who had a full sibling with a CM in the nervous system (HR=2.61, 95%CI:1.60-4.27) or in the eye, ear, face, or neck (HR=2.47, 95%CI: 1.46-4.18). Children who had a half sibling with a CM seemed to have a higher cancer risk in early adulthood (HR=1.87, 95%CI: 0.98-3.56).

CONCLUSIONS

Children who had a full sibling with a CM had no increased risk of cancer except for those who had a full sibling with a CM in the nervous system or in the eye, ear, face or neck. Children with a half-sibling with a CM tended to have an increased cancer risk in early adulthood, perhaps a result of chance. This study should be replicated using other data sources.

How Suitable Are Registry Data for Recurrence Risk Calculations? Validation of Diagnoses on 1,593 Families With Congenital Heart Disease

Background:

Congenital heart disease (CHD) occurs in approximately 1% of all live births, and 3% to 8% of these have until now been considered familial cases, defined as the occurrence of two or more affected individuals in a family. The validity of CHD diagnoses in Danish administrative registry data has only been studied previously in highly selected patient populations. These studies identified high positive predictive values (PPVs) and recurrence risk ratios (RRRs—ratio between probabilities of CHD given family history of CHD and no family history). However, the RRR can be distorted if registry data are used indiscriminately. Here, we investigated the consequences of misclassifications for the RRR using validated diagnoses on Danish patients with familial CHD.

Methods:

Danish citizens are assigned a civil registration number (CPR number) at birth or immigration, which acts as a unique identifier in the Danish registries, thus enabling connection of information from several registries. Utilizing the CPR number, we identified Danish patients with familial CHD and reviewed each patient’s file. We compared diagnoses from the registries with those manually assigned, which enabled calculation of the PPVs of diagnoses in the Danish registries, and from this, we deduced the false discovery rate (FDR). To measure the consequences on the RRR, the FDR was applied to a simulated data set with true RRR values of 2 and 10.

Results:

We validated diagnoses of 2,442 patients from 1,593 families. Of these, 874 patients were misclassified corresponding to an FDR of 36%. Applying this FDR on the simulated data sets, we found that the RRR decreased from 2 and 10 to 1.4 and 5.1, respectively. Lastly, we estimated that 11% of all cases with CHD were familial.

Conclusion:

We found that approximately one of nine of all cases with CHD are familial, and we also found that 36% of individuals with CHD in administrative medical registries are misclassified, which distort the RRR in simulated scenarios.

Genome-wide rare copy number variations contribute to genetic risk for transposition of the great arteries

BACKGROUND

Transposition of the great arteries (TGA) is an uncommon but severe congenital heart malformation of unknown etiology. Rare copy number variations (CNVs) have been implicated in other, more common conotruncal heart defects like tetralogy of Fallot (TOF), but there are as yet no CNV studies dedicated to TGA.

METHODS

Using high-resolution genome-wide microarrays and rigorous methods, we investigated CNVs in a group of prospectively recruited adults with TGA (n=101) from a single center. We compared rare CNV burden to well-matched cohorts of controls and TOF cases, adjudicating rarity using 10,113 independent population-based controls and excluding all subjects with 22q11.2 deletions. We identified candidate genes for TGA based on rare CNVs that overlapped the same gene in unrelated individuals, and pre-existing evidence suggesting a role in cardiac development.

RESULTS

The TGA group was significantly enriched for large rare CNVs (2.3-fold increase, p=0.04) relative to controls, to a degree comparable with the TOF group. Extra-cardiac features were not reliable predictors of rare CNV burden. Smaller rare CNVs helped to narrow critical regions for conotruncal defects at chromosomes 10q26 and 13q13. Established and novel candidate susceptibility genes identified included ACKR3, IFT57, ITGB8, KL, NF1, NKX1-2, RERE, SLC8A1, SOX18, and ULK1.

CONCLUSIONS

These data demonstrate a genome-wide role for rare CNVs in genetic risk for TGA. The findings provide further support for a genetically-related spectrum of congenital heart disease that includes TGA and TOF.

Genetics of congenital heart disease: the contribution of the noncoding regulatory genome

Congenital heart disease (CHD) is the most common type of birth defect. The advent of corrective cardiac surgery and the increase in knowledge concerning the longitudinal care of patients with CHD has led to a spectacular increase in life expectancy. Therefore, >90% of children with CHD, who survive the first year of life, will live into adulthood. The etiology of CHD is complex and is associated with both environmental and genetic causes. CHD is a genetically heterogeneous disease that is associated with long-recognized chromosomal abnormalities, as well as with mutation in numerous (developmental) genes. Nevertheless, the genetic factors underlying CHD have remained largely elusive, and it is important to realize that in the far majority of CHD patients no causal mutation or chromosomal abnormality is identified. However, new insights (alternative inheritance paradigms) and technology (next-generation sequencing) have become available that can greatly advance our understanding of the genetic factors that contribute to CHD; these will be discussed in this review. Moreover, we will focus on the discovery of regulatory regions of key (heart) developmental genes and the occurrence of variations and mutations within, in the setting of CHD.

Current Practice and Utility of Chromosome Microarray Analysis in Infants Undergoing Cardiac Surgery

OBJECTIVE

Traditionally, karyotype and fluorescence in situ hybridization (FISH) were used for cytogenetic testing of infants with congenital heart disease (CHD) who underwent cardiac surgery at our institution. Recently, chromosome microarray analysis (CMA) has been performed in lieu of the traditional tests. A standardized approach to cytogenetic testing does not exist in this population. The purpose of this study was to assess the utility of CMA based on our current ordering practice.

DESIGN

We reviewed the records of all infants (<1 year old) who underwent cardiac surgery at our institution from January 2010 to June 2013. Data included results of all cytogenetic testing performed. Diagnostic yield was calculated as the percentage of significant abnormal results obtained by each test modality. Patients were grouped by classification of CHD.

RESULTS

Two hundred seventy-five (51%) of 535 infants who underwent cardiac surgery had cytogenetic testing. Of those tested, 154 (56%) had multiple tests performed and at least 18% were redundant or overlapping. The utilization of CMA has increased each year since its implementation. The diagnostic yield for karyotype, FISH and CMA was 10%, 12%, and 14%, respectively. CMA yield was significantly higher in patients with septal defects (33%, P = .01) compared with all other CHD classes. CMA detected abnormalities of unknown clinical significance in 13% of infants tested.

CONCLUSIONS

In our center, redundant cytogenetic testing is frequently performed in infants undergoing cardiac surgery. The utilization of CMA has increased over time and abnormalities of unknown clinical significance are detected in an important subset of patients. A screening algorithm that risk-stratifies based on classification of CHD and clinical suspicion may provide a practical, data-driven approach to genetic testing in this population and limit unnecessary resource utilization.