Most cases of Angelman syndrome occur sporadically and are generally not associated with a family history. However, the risk of recurrence in a family can increase when specific genetic mechanisms are involved. Particularly, in the presence of chromosomal abnormalities or rearrangements affecting the critical region responsible for Angelman syndrome on chromosome 15, imprinting defects, or point mutations in the UBE3A gene, the likelihood of the syndrome recurring in the family can rise up to 50%.