The proper development of the atrioventricular canal into its prospective components (The heart septum and associated valves) to create a clear division between the four compartments of the heart and ensure proper blood movement through the heart, are essential for proper heart function. When this process does not happen correctly, a child will develop atrioventricular canal defect which occurs in 2 out of every 10,000 births. It also has a correlation with Down syndrome because 20% of children with Down syndrome have atrioventricular canal disease as well. This is a very serious condition and surgery is necessary within the first six months of life for a child.Brown, David MD "Atrioventricular Canal Defect" Children's Hospital Boston 20120 http://www.childrenshospital.org/az/Site521/mainpageS521P0.html Half of the children who are untreated with this condition die during their first year due to heart failure or pneumonia.
