transposition of great vessels
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displacement to the opposite side; in genetics, the nonreciprocal insertion of material deleted from one chromosome into another, nonhomologous chromosome.
transposition of great vessels a congenital heart defect in which the position of the chief blood vessels of the heart is reversed, so that the aorta arises from the right ventricle instead of the left and the pulmonary artery emerges from the left ventricle rather than from the right. The result is that oxygen-poor blood returning from the systemic circulation to the right side of the heart gets pumped back into the general circulation instead of being transported to the lungs, and oxygen-rich blood flows aimlessly to and from the lungs. The condition may be corrected by surgery.