Alagille Syndrome

Alagille syndrome is a genetic condition that affects the liver and heart and other parts of your body including your brain, blood vessels and bones. Treatment reduces life-threatening symptoms and manages other symptoms you might experience. Most people diagnosed with Alagille syndrome have a normal lifespan with mild symptoms.


Alagille syndrome affects your heart and liver and causes other symptoms throughout your body.
Alagille syndrome affects the valves and vessels in your heart and the bile ducts in your liver. Additional symptoms of the condition targets different areas of your body.

What is Alagille syndrome?

Alagille syndrome, also called Alagille-Watson syndrome, is a genetic condition that affects your liver and heart, along with other parts of your body. The condition can cause liver damage and structural heart abnormalities. People born with Alagille syndrome have distinct physical characteristics unique to this condition. Some of the possible complications of the disease are life-threatening.

What parts of my body does Alagille syndrome affect?

Alagille syndrome may also affect the development of your:


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Who does Alagille syndrome affect?

Alagille syndrome is genetic and passes from parents to children during conception. Only one parent needs to pass the gene to the child for the child to experience symptoms (autosomal dominant). Between 30% to 50% of cases pass to a child from an affected parent with the same diagnosis.

Some cases occur with no history of the affected gene in a person’s family history (sporadically).

How common is Alagille syndrome?

Alagille syndrome affects an estimated 1 in 30,000 to 45,000 people. This is an estimate because some cases go undiagnosed or are misdiagnosed for their most severe symptom.


How does Alagille syndrome affect my body?

Symptoms of Alagille syndrome affect each person differently. People diagnosed with this condition can experience bile (digestive fluid) backup in their liver caused by short or narrow bile ducts, or a decreased number of bile ducts, that move digested nutrients from your liver to your gallbladder and small intestine. When bile can’t pass through the bile ducts, it can damage your liver.

In addition, symptoms can also affect your heart and how it transports blood through your circulatory system. In the same way that the bile ducts are narrow or misshapen, heart valves and blood vessels narrow and cause symptoms that affect how much blood and/or oxygen get to different parts of your body.

Symptoms and Causes

What are the symptoms of Alagille syndrome?

Symptoms of Alagille syndrome are noticeable during infancy or early childhood but can go unnoticed until later in life among adults. They range in severity for babies and adults, even among family members with the same condition. Symptoms affect different parts of your body including your liver, heart and kidneys and cause distinct physical characteristics.

Liver symptoms

Symptoms of Alagille syndrome can cause liver damage. Signs that you have liver damage from Alagille syndrome include:

  • Yellow color to your skin and eyes (jaundice or icterus).
  • Feeling itchy.
  • Discolored (often yellow) group of fatty bumps on the skin (xanthomas).
  • Dark color to your urine.

Liver damage is the result of absent, narrow or misshapen bile ducts. Bile ducts are small tubes that help you digest fats by moving them from the liver to your gallbladder and small intestine. When your bile ducts can’t move fats through, the bile collects in the liver. Your liver is unable to perform its function of removing waste from your bloodstream when it’s backed up with bile.

Since your body can’t absorb fats and certain vitamins because of liver damage associated with Alagille syndrome, you could experience additional symptoms, including:

  • Weak bones.
  • Short stature and/or growth problems.
  • Vision problems that affect the cornea and retina.
  • Difficulty with coordination and movement.
  • Blood clots.
  • Developmental delays.
  • Scarring of the liver (cirrhosis).

An estimated 15% of people diagnosed with Alagille syndrome are at risk of severe liver disease and liver failure that can be life-threatening

Heart symptoms

Alagille syndrome can affect your heart and how it functions, including:

  • Problems with blood flow between your heart and lungs (pulmonary artery stenosis).
  • Structural abnormalities of your heart, including a hole between the two lower chambers of your heart (ventricular septal defect) or a combination of pulmonary artery stenosis, ventricular septal defect, displaced aorta and an enlarged right ventricle (tetralogy of Fallot).
  • Heart murmurs.
  • Blue color to your skin from low oxygen levels in your blood (cyanosis).

Symptoms of the face and body

Children born with Alagille syndrome have distinct physical characteristics that affect their face, including:

  • Wide and deep-set eyes.
  • Pointed, well-defined chin.
  • Large forehead.

Symptoms that affect their body include:

  • Skeletal abnormalities like irregularly shaped vertebrae bones (butterfly vertebrae).
  • Blood vessel abnormalities of the brain can cause internal bleeding and stroke.
  • Progressive narrowing of a major artery in the brain (Moyamoya syndrome).
  • Kidney problems (small size, cysts or limited function).
  • Pancreas is unable to break down and absorb nutrients.

Does Alagille syndrome affect a person’s mental abilities?

Only 2% of children with Alagille syndrome have intellectual disability. Separately, some children (16%) can have some mild delays in meeting gross motor milestones, such as walking.


What causes Alagille syndrome?

A problem with the JAG1 gene (usually a mutation in, but sometimes a deletion of it) causes more than 90% of Alagille syndrome cases. In 2% to 3% of cases, a mutation on the NOTCH2 gene causes Alagille syndrome. In around 3% of people with Alagille syndrome, the genetic cause is not known.

The JAG1 and NOTCH2 genes give your cells instructions to make proteins that create a communication pathway between cells so the cells know when to build certain parts of the body during fetal development. When there is a mutation on either of these genes or a deletion of genetic material on chromosome 20 that includes JAG1, your cells don’t have the instructions they need to do their job, which causes symptoms of the condition like structural heart defects, narrow bile ducts and skeletal abnormalities.

Diagnosis and Tests

How is Alagille syndrome diagnosed?

Alagille syndrome can be difficult to diagnose because the symptoms vary for each person. Diagnosis begins with a detailed medical history and an examination that reviews your symptoms. Your provider will suspect Alagille syndrome if you experience at least three of the following symptoms:

  • Misshapen bile ducts.
  • Liver disease or cholestasis.
  • Heart problems.
  • Skeletal abnormalities.
  • Vision problems.
  • Distinct facial features.

Several tests confirm the diagnosis including:

How do I tell if my baby has Alagille syndrome vs. biliary atresia?

Alagille syndrome and biliary atresia can cause similar effects and symptoms. In Alagille syndrome, your bile duct can restrict the flow of bile to the small intestine, causing bile to back up into the liver. In biliary atresia, damage or scarring of the bile ducts causes the same symptoms. Symptoms in newborns will be similar, including:

  • Dark urine.
  • Light stools.
  • Swollen belly.
  • Jaundice persisting several weeks after birth.

Babies with biliary atresia may also have other birth defects, similar to Alagille syndrome, including heart, kidney and spleen abnormalities. Some studies have shown that biliary atresia can involve mutations of the same gene that causes Alagille syndrome, the JAG1 gene.

Because biliary atresia is more common than Alagille syndrome, and because all the effects of Alagille syndrome may not be visible in infancy, healthcare providers may suspect biliary atresia first. The treatment will be the same in either case. If your child begins to show other signs of Alagille syndrome, they may be diagnosed later.

Management and Treatment

How is Alagille syndrome treated?

Treatment for Alagille syndrome is symptomatic since there is no cure for the condition. Treatment could include:

  • Taking vitamins A, D, E and K.
  • Drinking formula with medium-chain triglycerides for better nutrient absorption among infants.
  • Receiving nutrients from a feeding tube in your stomach (gastrostomy tube) or a tube in your nose to your stomach (nasogastric tube).
  • Taking medicine to treat liver disease (ursodeoxycholic acid).
  • Taking medicine to treat symptoms of itching (antihistamines, cholestyramine, naltrexone and rifampin) and using moisturizers or lotions.
  • Surgery to redirect bile between the liver and gastrointestinal tract (partial biliary diversion).
  • Surgery to treat symptoms that affect the heart, blood vessels and kidney.

Severe cases of Alagille syndrome with liver disease or liver failure require a liver transplant.

How to take care of myself and manage symptoms of Alagille syndrome?

Symptoms are unique to each person diagnosed with the condition. Your healthcare provider will advise you on what treatment options are right for you. Stay on schedule with preventative screenings to check the health of your heart and liver. If your provider prescribes a new treatment, expect to follow up with your provider a few weeks after the new treatment starts to track its effectiveness and manage side effects. Most treatment options minimize symptoms to make you more comfortable and prevent life-threatening consequences.


How can I prevent Alagille syndrome?

Since genetic changes cause Alagille syndrome, you can’t prevent the condition. If you have a history of Alagille syndrome in your family or plan on becoming pregnant and want to understand your risk of passing a genetic condition onto your child, talk to your healthcare provider about genetic testing.

Outlook / Prognosis

What can I expect if I have Alagille syndrome?

There is no cure for Alagille syndrome and it’s a lifelong condition. Treatment manages symptoms to provide comfort and prevent life-threatening symptoms.

Early intervention is important to minimize the effects of the condition. Severe liver and heart disease may shorten some lifespans, but many therapies are available to help improve these odds.

People diagnosed with Alagille syndrome will need to stay up to date on checkups with their providers to make sure the condition isn’t causing any life-threatening symptoms or to see the effectiveness of the treatment prescribed. Regular screenings consist of radiology images including:

What is the life expectancy for a person diagnosed with Alagille syndrome?

Most people diagnosed with mild symptoms of Alagille syndrome have a normal lifespan. Life expectancy for people diagnosed with Alagille syndrome who experience more severe symptoms, have a reduced life expectancy.

Discuss your symptoms with your healthcare provider. They will regularly order screening tests to check the function of your internal organs. Treatment focuses on preventing life-threatening symptoms.

Living With

When should I see my healthcare provider?

Visit your provider if you’re diagnosed with Alagille syndrome and have signs of liver damage including:

  • You have a yellow tone to your skin and/or eyes.
  • Your skin feels itchy without reason.
  • You have a group of fatty, discolored bumps on your skin.
  • Your urine appears darker than normal.

If you experience any symptoms of Alagille syndrome that prevent you from completing your daily routine, contact your healthcare provider. It’s also important to reach out to your provider if your baby or child diagnosed with Alagille syndrome misses developmental milestones through infancy and childhood.

When should I go to ER?

Symptoms of Alagille syndrome that affect your heart can be life-threatening. Visit the emergency room if you experience the following symptoms:

  • You have an irregular heartbeat.
  • It’s difficult for you to breathe.
  • Your skin, lips or fingernails appear blue.

Some cases of Alagille syndrome make you more at risk of having a stroke. Call 911 immediately if you experience any symptoms of a stroke including:

  • Numb feeling on one side of your body.
  • Trouble speaking or slurred speech.
  • Sudden vision problems.
  • Feeling dizzy, loss of balance or coordination.
  • Severe headache.

What questions should I ask my doctor?

  • How severe are my symptoms?
  • Do I need surgery?
  • When should I make a follow-up appointment to check if treatment is effective?
  • Are there side effects to the treatment you prescribed?

A note from Cleveland Clinic

Alagille syndrome affects each person diagnosed with the condition differently. Some people will experience very mild symptoms while others might need more treatment or surgery to combat severe symptoms. Work closely with your provider to get the care you need and stay up to date on preventative screenings to manage side effects and potentially life-threatening symptoms.

Medically Reviewed

Last reviewed on 07/26/2022.

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