ARTERIOHEPATIC DYSPLASIA (ALAGILLE-SYNDROME, WATSON-ALAGILLE-SYNDROME)

Alagille syndrome (AS) (arteriohepatic dysplasia, Alagille-Watson synd rome) is a multisystem disorder with hepatic, skeletal, eye, cardiac a nd renal manifestations. It results from mutation of the JAG1 gene, lo cated on chromosome 20, which encodes a ligand for Notch receptor(s). The interactions of Notch receptors and their ligands are crucial in c ontrolling cell fate decisions in a variety of developmental processes . AS varies in its severity, even in the same family, from asymptomati c gene carriers through to lethality due to inoperable cardiac or end- stage liver disease. However, advances in medical and surgical therapy have improved the prognosis at the severe end of the spectrum. It is hoped that the enhanced understanding of the biology of AS resulting f rom the cloning of the JAG1 gene will enable us to develop additional strategies for more effective treatments.