Alagille syndrome is a rare genetic disorder that primarily affects the liver, heart, eyes, kidneys and spine. It is caused by mutations in the JAG1 gene or NOTCH2 gene and leads to problems such as bile duct hypoplasia in the liver, heart defects and vision problems. Common symptoms include growth retardation and bone abnormalities. Treatment focuses on alleviating the symptoms, with a possible liver transplant in severe cases.