Conotruncal Heart Defects: A Narrative Review of Molecular Genetics, Genomics Research and Innovation

Congenital heart defects (CHDs) are most prevalent cardiac defects that occur at birth, leading to significant neonatal mortality and morbidity, especially in the developing nations. Among the CHDs, conotruncal heart defects (CTDs) are particularly noteworthy, comprising a significant portion of congenital cardiac anomalies. While advances in imaging and surgical techniques have improved the diagnosis, prognosis, and management of CTDs, their molecular genetics and genomic substrates remain incompletely understood. This expert review covers the recent advances from January 2016 onward and examines the complexities surrounding the genetic etiologies, prevalence, embryology, diagnosis, and clinical management of CTDs. We also emphasize the known copy number variants and single nucleotide variants associated with CTDs, along with the current planetary health research efforts aimed at CTDs in large cohort studies. In all, this comprehensive narrative review of molecular genetics and genomics research and innovation on CTDs draws from and highlights selected works from around the world and offers new ideas for advances in CTD diagnosis, precision medicine interventions, and accurate assessment of prognosis and recurrence risks.

Absent Pulmonary Valve Syndrome in a Fetus: A Case Report and Literature Review

INTRODUCTION

The main characteristics of absent pulmonary valve syndrome (APVS) include the absence or hypoplasia of the pulmonary valve, stenosis of the pulmonary valve annulus, and aneurysmal dilatation of the pulmonary trunk and its branches. In the more common type 1, the tetralogy of Fallot-like type, there is a ventricular septal defect, overriding aorta, pulmonary arterial dilatation, and absence of ductus arteriosus, The second type has an intact ventricular septum, less pulmonary artery dilatation, and a patent ductus arteriosus, with or without tricuspid atresia.

CASE REPORT

This APVS had an intact ventricular septum with an absent ductus arteriosus.

CONCLUSION

The APVS with intact ventricular septum with an absent ductus arteriosus may represent a third type of APVS.

Prenatal ultrasonic diagnosis of absent pulmonary valve syndrome: A case report

RATIONALE

Absent pulmonary valve syndrome (APVS) is a rare congenital heart disease that is often associated with tetralogy of Fallot (TOF). Here, we report 2 cases of APVS associated with TOF diagnosed via fetal echocardiography and discuss their specific ultrasonographic characteristics.

PATIENT CONCERNS

Two pregnant women with suspicion of fetal heart anomaly were referred from their local hospitals to our hospital for fetal malformation screening and detailed fetal echocardiography. Color and spectral Doppler flow imaging were utilized to evaluate the axis, size, situs, cardiac chambers, and both inflow and outflow tracts of the heart as well as the great arteries. Both cases had a severe dilatation of the pulmonary trunk and its branches and an absence or dysplasia of the pulmonary valve, which was associated with subaortic ventricular septal defect (VSD) with an overriding aorta. In addition, the fetus in case 1 showed a patent ductus arteriosus, and the fetus in case 2 showed arterial duct agenesis. Furthermore, color Doppler flow imaging showed a bi-directional multicolored flow signal in the pulmonary valve ring.

DIAGNOSES

Both fetuses were diagnosed with APVS associated with TOF.

INTERVENTIONS

No therapeutic intervention was performed.

OUTCOMES

On the request of the pregnant women and their families, both fetuses were aborted.

LESSONS

Although APVS is a rare congenital heart disease and often associated with TOF, it has an overall poor prognosis. Nowadays, it can be easily diagnosed via ultrasonography because of its typical ultrasonographic features, such as aneurysmal dilatation of pulmonary artery, massive regurgitation of the pulmonary valve, VSD, and an overriding aorta. Therefore, early fetal echocardiography screening should be performed for every fetus.