The disorder is inherited in an autosomal dominant pattern, and the estimated prevalence of Alagille syndrome is 1 in every 30,000[1][2] to 1 in every 40,000 live births.

[8] Signs and symptoms arising from liver damage in Alagille syndrome may include a yellowish tinge in the skin and the whites of the eyes (jaundice), itching (pruritus), pale stools (acholia), an enlarged liver (hepatomegaly), an enlarged spleen (splenomegaly) and deposits of cholesterol in the skin (xanthomas).

Bile duct paucity results in the reduced absorption of fat and fat-soluble vitamins (A, D, E and K), which may lead to rickets or a failure to thrive.

[11] Other presentations of Alagille's syndrome include butterfly vertebrae, ophthalmic defects, and distinct facial structures.

Many people with ALGS have similar facial features, including a broad, prominent forehead, deep-set eyes, and a small pointed chin.

The kidneys may also be affected because the mutations in JAG1 and NOTCH2 often lead to renal dysplasia, deformed proximal tubules, or lipidosis caused by the hindrance of lipid metabolism.

Alagille syndrome is inherited in an autosomal dominant pattern, which means one copy of the altered gene is sufficient to cause the disorder.

[17] Environmental factors that can result in gene mutations may include radiation such as ultraviolet rays from the sun, or chemicals such as benzene, which is found in cigarette smoke.

If a patient presents with multiple symptoms such as jaundice, heart murmur, and the characteristic facial features discussed above (deep set eyes, broad brow, etc.

Next-generation sequencing can be utilized to detect single nucleotide polymorphisms (SNPs) in the affected gene(s).

Indirect features on ultrasound of biliary atresia include abnormal and diminutive gallbladder shape, the triangular cord sign, and hepatic artery enlargement, though these can overlap with Alagille syndrome.

A high-calorie diet is very important, and often requires a gastrostomy tube to maintain the high caloric intake.

A portion of the bile produced by the liver is directed through a surgically created stoma into a plastic pouch on the patient's lower right abdomen.

Patients with biliary atresia may require a Kasai procedure to improve bile drainage; however, later liver transplantation is still often necessary.