The symptoms of Ivemark syndrome are due to the abnormal arrangement and malformation of certain internal organs. The organs of the chest and abdomen normally develop with specific left-right asymmetry, which means that the internal organs on the left side of the body are different than those on the right. In Ivemark syndrome, there are several characteristic findings involving the internal organs of the chest and abdomen including misplacement of the liver near the center of the body, abnormal positioning of the intestines (intestinal malrotation), and severe underdevelopment (hypoplasia) or absence (asplenia) of the spleen. Ivemark syndrome may also be known as right isomerism sequence because the left side of the body is identical to the right. For example, the right and left sides of the heart and lungs, which normally are distinct, may not be clearly defined.
Infants with Ivemark syndrome often have several heart defects that are present at birth (congenital heart defects) due to the failure of normal right-left asymmetry. The heart is normally located in the middle of the chest. The right and left sides of the heart are different and have different functions. The normal heart has four chambers. The two upper chambers are known as atria; one is located on the left side of the heart and one on the right side. They are separated from each other by a fibrous partition known as the atrial septum. The two lower chambers are known as ventricles; one is located on the left side and the other on the right. They are separated from each other by the ventricular septum. Valves connect the atria (left and right) to their respective ventricles. The valves allow for blood to be pumped through the chambers. Blood travels from the right ventricle through the pulmonary artery to the lungs where it receives oxygen. The blood returns to the heart through pulmonary veins and enters the left ventricle. The left ventricle sends the now oxygen-filled blood into the main artery of the body (aorta). The aorta sends the blood throughout the body.
Heart defects commonly associated with Ivemark syndrome include double outlet right ventricle, in which the main artery of the body (aorta) and the main artery of the lungs (pulmonary artery) both arise from the upper right chamber of the heart (ventricle) instead of the left; transposition of the great vessels, in which the aorta and the pulmonary artery are reversed; and ventricular or atrial septal defects, which are “holes” in the thin membrane (septum) that separates the chambers of the heart.
These various heart defects may cause a moderate or significant bluish discoloration to the skin of an affected infant due to a lack of oxygen in the blood (cyanosis). Some infants may develop heart murmurs or signs of congestive heart failure such as lack of energy and shortness of breath. The heart abnormalities associated with Ivemark syndrome can cause life-threatening complications early during infancy.
Infants with Ivemark syndrome may have an underdeveloped spleen, or the spleen may be missing altogether (asplenia). The spleen is an organ located in upper left part of the abdomen that filters out worn out blood cells. A missing or poorly functioning spleen may leave individuals more susceptible to repeated infections including infection of the blood (sepsis).
In some cases, additional findings have been reported including sudden, severe pain in the abdomen (acute abdomen) often due to abnormal twisting or the intestines (volvulus), narrowing (atresia) of the ducts that carry bile from the liver to the gallbladder (biliary atresia) and kidney abnormalities. Alterations of form, size and position of the pancreas may also be anticipated, and, in the rare instance of absence of the pancreas (pancreatic aplasia), total pancreatic insufficiency would be an additional complication of the affected neonate. The pancreas is a small organ located behind the stomach that secretes enzymes that travel to the intestines and aid in digestion. The pancreas also secretes other hormones such as insulin, which helps break down sugar.