Is Alagille syndrome inherited ?
This condition is inherited in an autosomal dominant pattern, which means one copy of the altered or deleted gene in each cell is sufficient to cause the disorder.  In approximately 30 to 50 percent of cases, an affected person inherits the mutation or deletion from one affected parent. Other cases result from new mutations in the gene or new deletions of genetic material on chromosome 20 that occur as random events during the formation of reproductive cells (eggs or sperm) or in early fetal development. These cases occur in people with no history of the disorder in their family.