Abstract
Congenital heart diseases are the most common type of human birth defects, resulting in a significant mortality worldwide. Cardiac outflow tract abnormalities often show severe illness, thus, it is important to understand their clinical manifestation in association with abnormal morphogenesis. Recent advances in molecular embryology have revealed that the heart arises from multiple distinct embryonic origins. Two different sources of cardiac progenitor cell lineages, termed as the second heart field and cardiac neural crest cells, are known to interact with each other and both contribute to the development of the cardiac outflow tract. Understandings of regulatory mechanisms of these cardiac progenitor cells have important implications for the interpretation of the outflow tract development and provide new insights into the morphogenesis of congenital outflow tract abnormalities. Numerous cardiac transcription factors regulate these progenitor cells during the heart development. Elucidation of the functional network of these transcription factors and characterization of transcriptional cascades for interaction between different progenitor lineages has provided a molecular framework and is essential for understanding the pathology of congenital cardiac outflow tract abnormalities associated with abnormal formation of three-dimensional structure. This review outlines the recent discoveries of development of the normal heart and the genetic basis of congenital cardiac outflow tract abnormalities.
