What causes transposition of the great arteries?
How often does transposition of the great arteries occur? CDC estimates that each year about 1,901babies in the United States are born with TGA (1). In other words, about 5 out of every 10,000 babies born in the United States each year is born with TGA. What problems do children with transposition of the great arteries have? Because the main arteries are switched, there are two separate blood circulations instead of a single connected one. Thus, blood with oxygen from the lungs does not get to the rest of the body. This means that TGA is a cyanotic (lacking oxygen) heart defect that leads to a bluish-purple coloring of the skin and shortness of breath. Symptoms appear at birth or very soon afterwards. How bad the symptoms are depends on whether there is a way for the two separate blood circuits to mix, allowing some oxygen-rich blood to get out to the body. This mixing can occur through other defects, such as a hole between the bottom chambers of the heart (a ventricular septal defect)
