['Mutations in the JAGGED1 gene are responsible for the Alagille syndrome, an autosomal dominant disorder characterized by neonatal jaundice, intrahepatic cholestasis, and developmental disorders affecting the liver, heart, vertebrae, eyes, and face. We screened a large group of patients for mutations in JAGGED1 and studied transmission of the mutations.', 'The coding sequence of the JAGGED1 gene was searched by single-strand conformation polymorphism and sequence analysis for mutations in 109 unrelated patients with the Alagille syndrome and their family if available.', 'Sixty-nine patients (63%) had intragenic mutations, including 14 nonsense mutations, 31 frameshifts, 11 splice site mutations, and 13 missense mutations. We identified 59 different types of mutation of which 54 were previously undescribed; 8 were observed more than once. Mutations were de novo in 40 of 57 probands.'] Are mutations in JAGGED1 gene predominantly sporadic in Alagille syndrome?