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. [Source: Wikipedia 
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