How Long Do People With Heterotaxy Syndrome Live?

Medically Reviewed on 2/2/2023
Heterotaxy Syndrome
Heterotaxy syndrome is often diagnosed before birth through prenatal testing.

Heterotaxy syndrome can affect the arrangement of thoracoabdominal organs and reduce the life expectancy of the affected child. Untreated serious heart conditions can result in early death. Most children who do not undergo corrective surgery for significant heart issues do not survive beyond the first year of life.

However, with advancements in medicine and technology over the past two decades, the improved techniques of early detection of the condition, such as prenatal (before birth) diagnosis and appropriate treatment, can help reduce the limitations and improve quality of life.

The life expectancy for heterotaxy syndrome depends on the severity of the condition. Researchers suggest that people with heterotaxy syndrome may survive up to 40 years with a mean life expectancy of 14 years.

What is heterotaxy syndrome?

Heterotaxy syndrome is a rare hereditary condition that interferes with organs developing normally. In this condition, the organs in the chest and abdomen are arranged abnormally, which causes problems with the heart and other organs.

The word heterotaxy means different arrangements and describes the body's abnormal organ arrangement. The incidence of heterotaxy is 1 in every 10,000 live births worldwide. However, the condition may develop later in life, making it more common than what is believed.

Heterotaxy syndrome is of two types:

  1. Right atrial isomerism
    • Usually includes several cardiac abnormalities. The child may lack a spleen and have the liver and/or other organs on the wrong side of the body.
    • This type includes a wide range of heart defects. Children's hearts may be built in a way that causes issues, such as valve problems or septal abnormalities and gaps in the heart's division walls. There could be erratic blood flow from the lungs to the heart. Other organs could be misplaced or missing, including the spleen.
  2. Left atrial isomerism
    • Usually includes valve abnormalities, electrical system issues, and septal flaws (holes in the muscle separating the two sides of the heart). Some children may lack a spleen entirely or have multiple tiny spleens.
    • Along with structural problems, children with this ailment may have an issue with the electrical system of the heart. Heart block may occur in certain situations. This happens when the upper and lower heart chambers are unable to exchange electrical signals. This disorder might result in a person having a few small spleens or none.

Heterotaxy syndrome is characterized by the following:

  • Asplenia syndrome: A condition in which the spleen is absent or underdeveloped.
  • Polysplenia: Refers to the presence of two or more spleens.
  • Left-right patterning deficits: Involve the defects in how the left and right sides of the body grow during embryonic development.
  • Cardiovascular malformations:
    • Dextrocardia syndrome (presence of the heart on the right side of the chest rather than the left side)
    • Atrioventricular septal defects
    • Double outlet right ventricles
  • Biliary atresia: Serious liver damage caused due to stagnation of bile in the liver, which is a result of blockade of bile ducts (tubes that carry bile from the liver to the gallbladder)
  • Malrotation of intestines
  • Respiratory issues
  • Recurrent infections

What are the symptoms of heterotaxy syndrome?

The symptoms of heterotaxy syndrome can vary widely depending on the organs involved and the extent of their abnormality.

Many problems are associated with heterotaxy syndrome, including:

  • Abnormal positioning of the heart and other organs
  • Heart defects, including abnormal heart chambers or abnormal connections between the major blood vessels
  • Abnormal blood vessels, such as abnormal connections between the arteries and veins
  • Heart symptoms may include slow or fast heart rate, fast breathing, cyanosis, difficulty feeding, and weight gain
  • Problems with the respiratory system, such as difficulty breathing, frequent infections, and difficulty removing mucus from the lungs
  • Problems with the digestive system, such as malrotation (abnormal twisting) of the intestines, frequent vomiting, difficulty feeding, and bilious (green) vomiting
  • Spleen issues and immune symptoms may include frequent infections
  • Low oxygen levels in the blood
  • Poor feeding or slow growth
  • Abnormalities of the urogenital system

What causes heterotaxy syndrome?

Abnormalities of organ development during embryonic development cause heterotaxy syndrome. The disorder may manifest spontaneously and without any known reasons. Although the precise cause of these abnormalities is unclear, researchers suggest that both hereditary and environmental factors may contribute to the condition.

Genetic factors

  • Given that heterotaxy syndrome frequently runs in families and is more prevalent in particular ethnic groups, it is believed to have a hereditary component. 
  • The disorder is frequently caused by mutations in specific genes involved in the development of the organs.

Environmental factors

  • The emergence of heterotaxy syndrome may be influenced by environmental factors, such as exposure to specific drugs or chemicals.

How is heterotaxy syndrome diagnosed?

Heterotaxy syndrome is often diagnosed before birth through prenatal testing, such as ultrasound. During an ultrasound, a healthcare provider may be able to see abnormalities in the positioning of the organs or heart defects that are characteristic of heterotaxy syndrome.

After birth, heterotaxy syndrome may be diagnosed based on a physical examination and the presence of certain symptoms, such as abnormal positioning of the organs or heart defects.

Six other tests that may be used to diagnose heterotaxy syndrome include:

  1. Echocardiogram
    • This test uses sound waves to create a detailed image of the heart. 
    • It can detect heart defects and abnormalities in the blood vessels.
  2. Electrocardiogram
    • This is a test that records the electrical activity of the heart. 
    • It can detect heart defects and abnormal rhythms.
  3. Chest X-ray
    • A chest X-ray can be used to evaluate the size and shape of the heart and to check for abnormalities in the blood vessels.
  4. CT scan or MRI
    • A CT scan or MRI can be used to create detailed images of the organs and blood vessels. 
    • These imaging tests can be useful in detecting abnormalities in the positioning and development of the organs.
  5. Abdominal ultrasound
    • This is a diagnostic imaging technique where ultrasound waves are used to generate images of inter organs and evaluate their functionality.
    • Large blood vessels, spleen, liver, kidneys, and others are well assessed through abdominal ultrasound.
  6. Genetic testing
    • This test may be done to determine if a person has a genetic mutation that is associated with heterotaxy syndrome.

What are the treatment options for heterotaxy syndrome?

The treatment of heterotaxy syndrome depends on the specific symptoms and abnormalities. Treatment may involve a combination of medications, surgery, and other therapies.

Medications

Drugs are given to treat certain symptoms or complications of heterotaxy syndrome, especially those that involve the cardiac and respiratory systems.

Medications are used to treat the following:

  • Heart defects
    • Certain medications, such as beta-blockers or blood thinners, may be used to treat heart defects.
    • Beta-blockers can help reduce the workload on the heart and lower blood pressure, whereas blood thinners can help prevent blood clots from forming in the blood vessels.
  • Abnormal rhythms
    • Heterotaxy syndrome can cause arrhythmia (abnormal heart rhythm), and medications may be used to regulate the heart's electrical activity.
    • Drugs used to treat arrhythmias include beta-blockers, calcium channel blockers, and anti-arrhythmic drugs.
  • Respiratory problems
    • If an individual with heterotaxy syndrome has respiratory problems, medications are given to improve breathing.
    • Bronchodilators may be used to relax the muscles in the airways and make it easier to breathe, whereas corticosteroids may be used to reduce inflammation in the airways.

Surgery

Surgery may be necessary to repair or correct heart defects or abnormalities in the positioning of the organs.

  • Cardiac surgery
    • May be used to repair heart defects, such as abnormal connections between the major blood vessels or abnormal heart chambers.
  • Vascular surgery
    • May correct abnormalities in the blood vessels, such as abnormal connections between the arteries and veins.
  • Thoracic surgery
    • Is performed to correct abnormalities in the positioning of the organs or to repair abnormalities in the chest cavity.
    • Developmental or functional defects of the lungs, such as problems with the lung tissue or airways, can be corrected with surgery.
  • Gastrointestinal surgery
    • A liver transplant may be necessary if an individual has severe liver damage or liver failure.
    • Gastrointestinal surgery may be necessary to correct abnormalities in the digestive system, such as malrotation (abnormal twisting) of the intestines.
    • Laparoscopic surgery is usually done to diagnose and treat problems in the abdomen, such as abnormalities in the positioning of the organs or abnormalities in the digestive system.

Other therapies

Therapies such as physical therapy and occupational therapy may be recommended to treat certain symptoms or complications of heterotaxy syndrome.

  • Physical therapy
    • Can help improve muscle strength and mobility, which may be affected by heterotaxy syndrome.
    • Physical therapists may use exercises, stretches, and other techniques to help individuals with the condition maintain their physical abilities.
  • Occupational therapy
    • May be recommended to help individuals with heterotaxy syndrome with activities of daily living, such as dressing, bathing, and eating.
    • Occupational therapists may recommend assistive devices, such as wheelchairs or adapted utensils, to help individuals with the condition perform their daily activities more easily.

It is crucial to remember that heterotaxy syndrome treatment is usually complicated and may include a group of medical professionals, including cardiologists, surgeons, and other specialists. To manage the disease and deal with any potential repercussions, ongoing medical care, and monitoring may be required.

Medically Reviewed on 2/2/2023
References
Image Source: iStock image

Long-term survival and phenotypic spectrum in heterotaxy syndrome: A 25-year follow-up experience https://pubmed.ncbi.nlm.nih.gov/30041775/

Heterotaxy Syndrome (Isomerism): https://www.nicklauschildrens.org/conditions/heterotaxy-syndrome

Heterotaxy syndrome with and without spleen: Different infection risk and management: https://www.jacionline.org/article/S0091-6749(16)31289-1/fulltext

Heterotaxy Syndrome: https://www.nationwidechildrens.org/conditions/heterotaxy-syndrome