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.
Angelman syndrome signs and symptoms include: 1  Developmental delays, including no crawling or babbling at 6 to 12 months. 2  Intellectual disability. 3  No speech or minimal speech. 4  Difficulty walking, moving or balancing well (ataxia) 5  Frequent smiling and laughter. 6  Happy, excitable personality.