What's the problem when a child has transposition of the great arteries?

Cyanosis: Cyanosis, or blue-tinged skin or mucous membranes, is caused by low oxygen levels in the blood (hypoxemia). In transposition of the great arteries, cyanosis is due to the aorta arising from the right ventricle (and the pulmonary artery arising from the left ventricle) which leads to de-oxygenated systemic venous blood being redirected to the body (and oxygenated blood recirculating in the lungs).