A regular expression is a pattern that the regular expression engine attempts to match in input text. A pattern consists of one or more character literals, operators, or constructs. For a brief introduction, see .NET Framework Regular Expressions.
(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.
1 Angelman syndrome (AS) is a developmental disorder affecting the brain. 2  AS has been shown in most cases to have a genetic cause. 3  Specifically, it is thought to occur from a problem on a chromosome called 15q11-13 that is passed from a mother to the child.