Final answer:
The cardiac manifestations of Turner syndrome and Noonan syndrome are different.
Step-by-step explanation:
The cardiac manifestations of Turner syndrome and Noonan syndrome are different.
In Turner syndrome, which is caused by a missing or incomplete X chromosome in females, the most common cardiac manifestation is coarctation of the aorta. This is a condition where the aorta, the main artery that carries blood from the heart to the rest of the body, is narrowed or constricted. Other cardiac issues can also occur, such as bicuspid aortic valve, a condition where the valve that controls blood flow from the heart's left ventricle to the aorta has only two leaflets instead of the normal three.
In Noonan syndrome, which is caused by mutations in various genes, the most common cardiac manifestations include pulmonic stenosis, hypertrophic cardiomyopathy, and atrial septal defects. Pulmonic stenosis is a condition where the pulmonic valve, which controls blood flow from the right ventricle to the lungs, is narrowed. Hypertrophic cardiomyopathy is a condition where the heart muscle becomes thickened, making it harder for the heart to pump blood effectively. Atrial septal defects are holes in the wall that separates the upper chambers of the heart.