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Ivemark syndrome

Also known as: Asplenia syndrome, Isomerism of the Right Atrial Appendages, Heterotaxy syndrome


Ivemark syndrome is now largely a historical term for the association of congenital asplenia (absence of a spleen) with malformations of the cardiovascular system (which transports blood through the body via the hearts, lungs and veins) and abnormal arrangement of the chest and abdominal (thoraco-abdominal) organs.

Ivemark syndrome is part of a group of disorders known as heterotaxy syndromes which includes both right (Ivemark) and left isomerism. In these conditions, there is a failure of the normal lateralisation of internal organs (ie left and right sided) resulting in mirror imaging of certain structures on both sides of the body.


Medical text written February 2008 by Dr Jonathan Forsey, Specialist Registrar Paediatric Cardiology and Dr Robin Martin, Consultant Paediatric Cardiologist, Bristol Royal Hospital for Children, Bristol, UK.

What are the symptoms?

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).

How is it treated?

Treatment is centred on the relief of the underlying cardiac abnormalities. This is achieved by surgery. Surgery may also be required for fixation of the bowel to prevent gut malrotation causing symptoms and bowel damage.

Inheritance patterns and prenatal diagnosis

Inheritance patterns
Ivemarks or right atrial isomerism accounts for approximately one per cent of congenital heart disease in the infant. It is an abnormality of the formation of the left-right axis of the body, with research currently examining the role of signalling molecules in embryonic cilia development. There is no clear inheritance pattern, although some genetic markers have now been identified in some cases, indicating that this is a complex multi-factorial mechanism. The recurrence risk for future pregnancies is approximately five per cent. There is a slight male preponderance and the syndrome is more common in certain racial groups.

Prenatal diagnosis
Although specific genes have been linked, there are no definite genetic markers that can be tested for antenatally. The diagnosis is made by detecting the cardiovascular abnormalities on the 18 to 20 week antenatal ultrasound scan.

Is there support?

There is no support group for Ivemark syndrome in the UK. Cross referrals to other entries in The Contact a Family Directory are intended to provide relevant support for those particular features of the disorder. Organisations identified in those entries do not provide support specifically for Ivemark syndrome.

Families can use Contact a Family's freephone helpline for advice, information and, where possible, links to other families. Contact a Family's web-based linking service can be accessed at