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(For our list of subjects with an imprinting defect, click here.). UBE3A Mutation. Malfunction of the UBE3A gene on the maternal chromosome #15 seems to be the cause of Angelman syndrome. In the case of a UBE3A mutation, there is a mistake in the genetic code of the UBE3A gene.
Rarely, Angelman syndrome can also be caused by a chromosomal rearrangement called a translocation, or by a mutation or other defect in the region of DNA that controls activation of the UBE3A gene. These genetic changes can abnormally turn off (inactivate) UBE3A or other genes on the maternal copy of chromosome 15.n some people who have Angelman syndrome, the loss of a gene called OCA2 is associated with light-colored hair and fair skin. The OCA2 gene is located on the segment of chromosome 15 that is often deleted in people with this disorder.