Alagille syndrome and nephroblastoma: Unusual coincidence of two rare disorders.

Alagille syndrome is a rare developmental disorder combining bile duct paucity, congenital cardiopathy, facial dysmorphy, vertebrae defects, and ocular abnormalities, and frequent renal abnormalities. It does not usually predispose to malignancies. Nephroblastoma has been observed in many developmental disorders, but never in Alagille syndrome. We report two original cases of nephroblastoma associated to Alagille syndrome. We identified a new V136G JAG1 missense mutation in one patient and a constitutional deletion of 20p12 in the other. In one nephroblastoma an additional somatic 1p36 deletion was present. The link between Alagille syndrome, JAG1 alterations and nephroblastoma is discussed.