Liver problems are common in children with Alagille syndrome and are often the first sign of the condition. In Alagille syndrome, the liver has fewer bile ducts than normal.

Bile ducts are tiny tubes that carry bile from the liver to the gallbladder and small intestine. When there are fewer bile ducts, bile can build up in the liver. This is called cholestasis. It usually starts in the first three months of life.

Some children have mild cholestasis and do not have major problems. In other children, cholestasis can be more severe, causing symptoms, complications and damage to the liver over time.

Not every child with Alagille syndrome will have liver problems. However, most will face liver issues at some point in their life.

In some children, liver problems get better on their own between the ages of four and ten – but this doesn’t happen for everyone. Unfortunately, doctors can’t predict which children will get better, get worse or stay the same.

Children and adults with Alagille syndrome often share similar facial features, including:

• a high, broad forehead
• deep-set, widely spaced eyes
• a small, pointed chin

These features do not make people look unusual. They are simply common among those with Alagille syndrome. These features often become more noticeable as children get older.

Heart problems are common in Alagille syndrome, with most children having some type of heart issue. They range from issues that cause no harm to serious problems that affect the structure and function of the heart. In some children, heart problems can be very serious.

The most common heart problems include:

• Pulmonary artery stenosis: narrowing of the pulmonary artery, which carries blood from the heart to the lungs. Sometimes the only sign is a heart murmur (an extra sound in the heartbeat).
• Tetralogy of Fallot (TOF): a condition where four different problems affect how the heart works.
• Atrial septal defect: a small hole between the two upper chambers of the heart.
• Ventricular septal defect: a small hole between the two lower chambers of the heart.
• Coarctation of the aorta: narrowing of the aorta, the largest artery in the body.

Alagille syndrome can affect different parts of the eye, including the cornea, iris and retina. One common change is called posterior embryotoxon. This means there is a thicker ring around the clear, front part of the eye. It happens when the eye forms a little differently before birth.

Eye differences in Alagille syndrome usually don’t affect vision.

In Alagille syndrome, the bones of the spine may look a bit different on X-rays. Sometimes they have a small notch or a “butterfly-like” shape. These changes usually don’t cause any problems.

Children with Alagille syndrome may have weaker bones, which means they can break more easily. Bone growth can also be affected. Some of these problems are due to Alagille syndrome. Others are caused by problems with nutrition and low levels of vitamin D.

Children with Alagille syndrome are often smaller in height and weight and they are likely to stay smaller as they grow.

Some children with Alagille syndrome have kidney problems. Their kidneys might be smaller than normal or shaped differently. Sometimes they don’t develop properly, or they contain cysts. There can also be problems with how their kidneys work.

Alagille syndrome can affect blood vessels in different parts of the body, including the brain, liver, lungs, heart and kidneys. When blood vessels in the brain are affected, it can cause:

• bleeding in the brain (intracranial bleeding or stroke)
• narrowing of the main blood vessel to the brain (moyamoya disease)
• bulges in blood vessels (aneurysms)

Some children with Alagille syndrome also have:

• problems with their pancreas
• delays in reaching development milestones
• trouble with memory, concentration and problem solving