Health Library

Heterotaxy Syndrome

What Causes Heterotaxy Syndrome?

Changes in certain genes or environmental factors during pregnancy may cause this condition. Often, the exact reason isn’t known. Heterotaxy syndrome is something a person is born with.

Heterotaxy Syndrome Types

Heterotaxy syndrome includes a wide range of conditions involving unusual arrangements of the body’s internal organs. This can cause various health problems depending on which organs are affected.

Heterotaxy syndrome can range from mild to severe. In some cases, it may go unnoticed because the person has no symptoms. For instance, if the gallbladder or appendix is on the opposite side of the body, it might only be discovered during imaging for an unrelated issue. In other cases, heterotaxy can cause serious complications, especially when it involves the heart or other vital organs. These more severe forms require careful management and treatment by specialists to ensure the best possible outcomes.

One common issue is with the spleen, an organ that helps fight infections. Sometimes, the spleen doesn’t work right or is missing altogether, which can make it hard for a child to recover from surgeries or illnesses. Other times, instead of one spleen, there are several small spleens (this is called polysplenia).

Several types of heterotaxy syndrome affect the heart, including:

• Right Atrial Isomerism: This type of heterotaxy syndrome often causes severe heart defects, like holes in the heart and problems with the heart valves. The spleen might be missing, and the liver and other organs might be on the wrong side of the body.
• Left Atrial Isomerism: This type of heterotaxy syndrome can also cause heart defects, but the heart issues may be less severe. Some children may need a pacemaker because the heart’s electrical system doesn’t work properly. In this type, the spleen might be missing, or there could be several small spleens.
• Dextrocardia: Dextrocardia is a condition where the heart is located on the right side of the chest instead of the left. Children with dextrocardia often have other vital organs misplaced. Dextrocardia can occur as part of heterotaxy syndrome or in isolation (without heterotaxy).

A heterotaxy syndrome diagnosis can also mean that the heart or other organs are in the right place, but facing the wrong direction.

What are the Symptoms of Heterotaxy Syndrome?

This condition can affect just a few organs or many different ones, making each case unique. The symptoms depend on which organs are affected and how they are arranged. In most cases of right atrial isomerism and some cases of left atrial isomerism, symptoms will show up at birth or shortly after. These might include:

• Heart defects that can lead to breathing problems and a bluish tint to the skin or lips due to lack of oxygen.
• Difficulty feeding and failure to thrive because the baby tires easily and doesn’t get enough nutrients.
• Increased risk of infections, especially if the spleen is missing or not working properly.
• Digestive problems due to abnormal positioning of the stomach or intestines.
• Extreme sleepiness, which happens because the body is not getting enough oxygen.

How is Heterotaxy Syndrome Diagnosed?

Doctors can diagnose heterotaxy syndrome using imaging tests like CT scans, MRIs and echocardiograms to see the position of the organs. Genetic tests may also be done to check for gene changes that could cause the condition.

Heterotaxy syndrome is often found before birth using fetal echocardiography and ultrasound. Early detection can help doctors plan the medical care needed right after birth.

Not all “sidedness” conditions will be diagnosed as heterotaxy. For example, situs inversus is a condition where the major organs are mirrored from their regular positions. In this case, the heart could be on the right side instead of the left. Even though this involves a change in how the body’s organs are positioned, it is a different condition. A diagnosis of heterotaxy affects the arrangement of other organs.

With cases of sidedness, there are normal variations that don’t cause complications. Some people might have slight variations in organ positioning that do not cause health problems and are not considered heterotaxy. For instance, a slightly rotated stomach or a differently positioned appendix might not be classified as heterotaxy and does not affect organ function.

How is Heterotaxy Syndrome Treated?

Treatment for heterotaxy syndrome depends on which organs are affected and how severe the problems are. It often involves managing heart defects with surgeries or other procedures, such as:

• Placing a shunt or pacemaker.
• Performing surgeries to correct heart defects.
• Prescribing medicines like antibiotics to help prevent infection or blood pressure medications to lower blood pressure.

Children with heterotaxy syndrome usually need care from a team of specialists, including cardiologists and surgeons, to manage their condition effectively.

Infants with heterotaxy syndrome may have complications at birth, such as serious heart defects or other organ-related issues. These complications can be severe and require prompt medical attention.

Heterotaxy Syndrome Prognosis

The outlook for someone with heterotaxy syndrome varies widely. Some people may have mild symptoms and live relatively normal lives. Others may have severe complications that require ongoing medical care. Advances in medical and surgical treatments have improved the survival rates and quality of life for many patients with heterotaxy syndrome.

Heterotaxy syndrome is a complex disorder, and every patient is different. Patients and their families should have a team of trusted specialists who can help them understand and manage their unique organ arrangement.