Mutations in a critical gene that controls heart and blood vessel development in mouse embryos mimics a type of congenital heart disease in humans, according to new research led by Michael S. Parmacek, MD, Director of the Penn Cardiovascular Institute at the University of Pennsylvania School of Medicine. Congenital heart disease (CHD) occurs in approximately one in one hundred newborn infants. Knowing the basic genetic causes of congenital heart disease will allow for the development of CHD prenatal diagnosis, as well as treatments to prevent or correct infant and adult heart disease. Using genetically engineered mice, the researchers found that mice with a mutation in the gene for myocardin-related transcription factor B (MRTF-B) had defects in developing arteries associated with the embryonic heart. Specifically, these mice had a variation of a childhood condition known as a truncus arteriosis defect, a relatively rare form of CHD that occurs in infants in which the aorta does not appropriately separate from the pulmonary artery. As a result, oxygenated and deoxygenated blood mix, resulting in insufficient amounts of oxygen being transported to tissues. This causes cyanosis, which is commonly referred to as “blue babies.” Senior author Parmacek and his colleagues published their findings in this week’s early online edition of the Proceedings of the National Academy of Sciences.
