Infants with this condition present shortly after birth usually secondary to their cardiac abnormalities. Typical signs and symptoms include cyanosis (blueness), shortness of breath, loss of energy and cardiac failure. The typical cardiac abnormalities include total anomalous pulmonary venous drainage (TAPVD), transposition of the great vessels (TGA), atrioventricular septal defects (AVSD), double outlet right ventricle (DORV) and pulmonary stenosis ((PS) see entry Heart Defects).
Other abnormalities include midline liver, malrotation and malfixation of the bowel. There may be mirror imaging of the right lung, with both lungs resembling a normal right lung.
Left atrial isomerism is usually associated with less severe heart defects but these may still present in a similar manner to those with right atrial isomerism. Typical findings would include atrioventricular septal defect and abnormalities of the systemic veins. Many will also have heart rhythm abnormalities and these include sinus node dysfunction and atrioventricular block that may require pacemaker implantation.
Associated gut malrotation is usually less severe but may need treatment. Rarely it can be associated with a severe liver problem called biliary atresia that results in jaundice (see entry Liver disease).