In hypoplastic left heart syndrome, the left side of the heart (the side which receives oxygen-rich blood from the lungs and pumps it out to the body) -- including the aorta, aortic valve, left ventricle and mitral valve -- is underdeveloped. This results in a situation where the left side of the heart is completely unable to support the circulation needed by the bodys organs, though the right side of the heart (the side that delivers blood to the lungs) is typically normally developed. This heart defect is usually fatal within the first days or months or life unless its treated. It may have a genetic link, either occurring due to a defect in a gene, a chromosome abnormality, or environmental exposure but in many children, it occurs sporadically (by chance), with no clear reason evident for their development. The rate of occurrence is increased in patients with certain genetic disorders like Turner, Noonan, Smith-Lemli-Opitz, or Holt-Oram syndrome. Certain chromosomal duplications, translocations, and deletions also are associated with it.
Please consult a clinical genetics center where you can be examined and tested appropriately as there is an increased risk of having other affected children, often with the same heart defect. Most congenital heart defects cannot be prevented and antenatal echocardiography can be used before birth to accurately identify heart defects.