What is the Difference Between Alagille Syndrome and Biliary Atresia

Alagille syndrome and biliary atresia are two genetic conditions that cause bile duct abnormalities and affect the liver. They are also genetic conditions that can cause similar effects and symptoms. Both these conditions affect the function of the bile duct and cause problems in the liver. However, alagille syndrome can also affect the heart and other parts of the body.

The key difference between alagille syndrome and biliary atresia is their nature. Alagille syndrome is an inherited condition of the liver mainly due to a mutation in a gene called JAG1, while biliary atresia is a non-inherited condition of the liver mainly due to mutations in genes such as PKD1L1, CRIPTO, and LEFTY.

1. Overview and Key Difference
2. What is Alagille Syndrome
3. What is Biliary Atresia
4. Similarities – Alagille Syndrome and Biliary Atresia
5. Alagille Syndrome vs Biliary Atresia in Tabular Form
6. Summary – Alagille Syndrome vs Biliary Atresia
7. FAQ: Alagille Syndrome and Biliary Atresia

What is Alagille Syndrome?

Alagille syndrome is a genetic disorder that causes liver damage and heart abnormalities. It can also affect the kidneys, pancreas, eyes, skeleton, and blood vessels. This condition is due to a mutation in a gene called JAG1. Alagille syndrome usually affects about 1 in 30,000 to 45,000 people in the world. The symptoms of this condition may include yellow skin and eyes, an itchy feeling, a discolored group of fatty bumps on the skin, dark color in the urine, problems with blood flow between the heart and lungs, weak bones, blood clots, developmental delays, vision problems in cornea and retina, and scarring of the liver.

Figure 01: Tetralogy of Fallot is a Common Heart Defect Experienced in Alagille Syndrome Patients

Alagille syndrome can be diagnosed through medical history, family history, physical examination, liver biopsy, eye examination, spin X-ray, kidney function tests, and genetic tests. Furthermore, treatment options for Alagille syndrome include taking vitamins A, D, E, and K, drinking formula with medium-chain triglycerides, receiving nutrients from a feeding tube in the stomach, taking ursodeoxycholic acid for liver disease, having surgery to redirect bile between the liver and gastrointestinal tract, and liver transplant.

What is Biliary Atresia?

Biliary atresia is a genetic condition in infants where part or all of the bile duct is malformed. In this condition, the baby’s bile ducts are blocked, and bile can’t be sent from the liver to the small intestine. This affects the newborn liver. This condition can be caused by mutations in genes such as PKD1L1, CRIPTO, LEFTY, ARF6, EFEMP1, GPC, NODAL, and ADD3, problems with the bile duct development in the womb, autoimmune reactions, and viral infections (cytomegalovirus, reo, and rota viruses). Therefore, it doesn’t pass from parents to children. The symptoms of this condition are jaundice, pale, light, clay-colored stool, dark urine, poor weight gain, irritability, portal hypertension, and liver enlargement.

Figure 02: Biliary Atresia

Biliary atresia can be diagnosed through medical history, physical examination, blood test, liver biopsy, liver ultrasound, and genetic test. Furthermore, treatment options for biliary atresia are surgery called the Kasai procedure and liver transplant.

Similarities Between Alagille Syndrome and Biliary Atresia

Alagille syndrome and biliary atresia are two genetic conditions that cause bile duct abnormalities and affect the liver.
Both these conditions cause similar effects and symptoms, such as jaundice, dark urine, etc.
These conditions can be diagnosed through medical history, physical examination, liver biopsy, and genetic tests.
They can be treated through liver transplants and other surgeries.

Difference Between Alagille Syndrome and Biliary Atresia

Definition

Alagille syndrome is an inherited condition that results in short or narrow bile ducts or a decreased number of bile ducts.
Biliary atresia is a non-inherited condition that results in malformed bile ducts.

Cause

Alagille syndrome is caused by JAG1gene mutation.
Biliary atresia is caused by mutations in genes such as PKD1L1, CRIPTO, LEFTY, ARF6, EFEMP1, GPC, NODAL, ADD3, problems with the bile duct development in the womb, autoimmune reactions and viral infections (cytomegalovirus, reo and rota viruses).

Symptoms

Symptoms of alagille syndrome include jaundice, itchy skin, delayed growth, hard skin bumps, heart murmur, changes in the blood vessels, facial characteristics, spinal growth changes, kidney disease, enlarged spleen, and white ring in the eye.
Symptoms of biliary atresia include jaundice, pale stool, dark or amber-colored urine, itchy skin, irritability, trouble gaining weight, and swollen belly due to fluid build-up.

Diagnosis

Alagille syndrome is diagnosed by medical history and family history, physical examination, liver biopsy, eye examination, spin X-ray, abdominal ultrasound, kidney function test, and genetic test.
Biliary atresia is diagnosed by medical history, physical examinations, ultrasound, HAD scan, liver biopsy, and genetic test.

Treatment

Alagille syndrome is treated by medicine to increase bile flow out of the liver, to reduce itching, skin care, such as moisturizers, vitamin supplements, high calorie food supplements, surgery to redirect bile so that less bilirubin ends up in the blood and liver transplant.
Biliary atresia is treated by surgery called the Kasai procedure and liver transplant.

The following table summarizes the difference between Alagille syndrome and biliary atresia.

Summary – Alagille Syndrome vs Biliary Atresia

Alagille syndrome is an inherited condition, while biliary atresia is a non-inherited condition. Alagille syndrome results in short or narrow bile ducts or a decreased number of bile ducts, and it is caused by a mutation in a gene called JAG1, whereas biliary atresia results in malformed bile ducts and it can be caused by mutations in genes such as PKD1L1, CRIPTO, LEFTY, ARF6, EFEMP1, GPC, NODAL, ADD3, problems with the bile duct development in the womb, autoimmune reactions, and viral infections. This is the summary of the difference between Alagille syndrome and biliary atresia.

FAQ: Alagille Syndrome and Biliary Atresia

1. What is the most common heart defect in Alagille syndrome?

Alagille syndrome causes liver, heart, kidney, pancreas, skeleton, and blood vessel problems. Most common Alagille-related heart defects involve the pulmonary arteries. Therefore, the most common heart defect in this condition is peripheral pulmonary stenosis. Other potential structural cardiac defects include the Tetralogy of Fallot.

2. How to cure Alagille syndrome?

Management of Alagille syndrome is aimed at preventing and monitoring for complications. These include medicine to increase bile flow out of the liver, reduce itching, moisturize, give nutrients from a feeding tube in the stomach, taking ursodeoxycholic acid for liver disease, surgery to redirect bile between the liver and gastrointestinal tract, and liver transplant.

3. What is another name for biliary atresia?

Biliary atresia is also known as extrahepatic ductopenia and progressive obliterative cholangiopathy. It is a newborn’s disease of the liver in which one or more bile ducts are abnormally narrow, blocked, or absent. This disease can be congenital or acquired.

4. What is the cause of biliary atresia?

Experts don’t know what the main cause of biliary atresia is. Research suggests that infants develop biliary atresia in the womb or shortly after birth. The possible causes of biliary atresia mutations in genes such as PKD1L1, CRIPTO, LEFTY, ARF6, EFEMP1, GPC, NODAL, ADD3, bile duct development problems in the womb, autoimmune reactions, and infections with certain viruses.

5. What is the life expectancy of a baby with biliary atresia?

In biliary atresia, most infants develop cirrhosis within 6 months and liver failure within 1 year. Fewer than 10% of children who don’t receive treatment live past the age of 3 years. With surgery like the Kasai procedure, the majority of children live into adulthood.

Reference:

1. “Alagille Syndrome: Symptoms, Causes & Treatment.” Cleveland Clinic.
2. “Biliary Atresia: Symptoms, Causes, Diagnosis, and Treatment.” Healthline, Healthline Media.

Image Courtesy:

1. “Tetralogy of Fallot” By Mariana Ruiz LadyofHats – (Public Domain) via Commons Wikimedia
2. “Orphan with biliary atresia” By Wen-Yan King (CC BY-NC-SA 2.0) via Flickr

CONTENTS

What is Alagille Syndrome?

What is Biliary Atresia?

Similarities Between Alagille Syndrome and Biliary Atresia