Alagille syndrome diagnostic criteria

To make a diagnosis of Alagille syndrome, a positive liver biopsy and the presence of three of the following symptoms are usually required:

• liver symptoms
• heart abnormalities or murmurs
• skeletal abnormalities
• posterior embryotoxon
• facial features typical of Alagille syndrome

A blood sample may also be tested to look for the JAG1 gene mutation. The gene mutation can be identified in 95 percent of people with a diagnosis of Alagille syndrome based on signs and symptoms.^[1] A person can also be diagnosed with Alagille syndrome if the JAG1 gene mutation alone is present—even when no major symptoms of the disorder are evident.