Previous studies have demonstrated that a wide spectrum of JAG1 mutations result in AGS. These include total gene deletions, protein truncating, splicing and missense mutations which are distributed across the coding region of the gene. Here we present results of JAG1 mutation screening by SSCP and FISH in 105 patients with AGS. For these studies, new primers were designed for 12 exons. Mutations were identified in 63/105 patients (60%)