Alagille syndrome laboratory findings

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

In addition to various imaging modalities, laboratory tests may be conducted evaluating the bilirubin levels. A liver biopsy may also be conducted on the bile duct to further supplement bilirubin testing.

Total Bilirubin >6.5 mg/dL, Conjugated Bilirubin >4.5 mg/dL, and cholesterol >520 mg/dL in children younger than 5 years of age are likely be associated with severe liver disease in later life ^[1].

Sequence analysis of JAG1 detects mutation in 90% of individuals with symptoms. Around 7% of affected individuals have microdeletion of 20p12. Mutations in NOTCH2 is found in less than 1%. If family-specific mutation is known, molecular genetic testing is offered to first-degree relatives.

Prenatal testing for pregnancies at increased risk is possible if the JAG1 or NOTCH2 disease-causing mutation in an affected family member is known. Prenatal testing cannot predict the occurrence or severity of clinical manifestations.