Congenital heart diseases: genetics, non-inherited risk factors, and signaling pathways

AbstractBackgroundCongenital heart diseases (CHDs) are the most common congenital anomalies with an estimated prevalence of 8 in 1000 live births. CHDs occur as a result of abnormal embryogenesis of the heart. Congenital heart diseases are associated with significant mortality and morbidity. The damage of the heart is irreversible due to a lack of regeneration potential, and usually, the patients may require surgical intervention. Studying the developmental biology of the heart is essential not only in understanding the mechanisms and pathogenesis of congenital heart diseases but also in providing us with insight towards developing new preventive and treatment methods.Main bodyThe etiology of congenital heart diseases is still elusive. Both genetic and environmental factors have been implicated to play a role in the pathogenesis of the diseases. Recently, cardiac transcription factors, cardiac-specific genes, and signaling pathways, which are responsible for early cardiac morphogenesis have been extensively studied in both human and animal experiments but leave much to be desired. The discovery of novel genetic methods such as next generation sequencing and chromosomal microarrays have led to further study the genes, non-coding RNAs and subtle chromosomal changes, elucidating their implications to the etiology of congenital heart diseases. Studies have also implicated non-hereditary risk factors such as rubella infection, teratogens, maternal age, diabetes mellitus, and abnormal hemodynamics in causing CHDs.These etiological factors raise questions on multifactorial etiology of CHDs. It is therefore important to endeavor in research based on finding the causes of CHDs. Finding causative factors will enable us to plan intervention strategies and mitigate the consequences associated with CHDs. This review, therefore, puts forward the genetic and non-genetic causes of congenital heart diseases. Besides, it discusses crucial signaling pathways which are involved in early cardiac morphogenesis. Consequently, we aim to consolidate our knowledge on multifactorial causes of CHDs so as to pave a way for further research regarding CHDs.ConclusionThe multifactorial etiology of congenital heart diseases gives us a challenge to explicitly establishing specific causative factors and therefore plan intervention strategies. More well-designed studies and the use of novel genetic technologies could be the way through the discovery of etiological factors implicated in the pathogenesis of congenital heart diseases.