Spatial and temporal silencing of the human maternal UBE3A gene.

Angelman syndrome (AS) is characterized by severe cognitive disruption, seizures, difficulty speaking and ataxia. Nearly all cases are attributed to the disruption or absence of the imprinted maternal copy of UBE3A, transcribing an E3-type ubiquitin ligase. Much of what is known about the molecular and biochemical changes in the CNS associated with AS has been obtained through this murine model. This widely used mouse model created by a null mutation of the maternal UBE3A gene recapitulates the major phenotypes characteristic of AS patients. The imprinting of maternal UBE3A was originally believed to be brain region specific; however recent reports using the AS mouse model have revealed a more wide-spread absence of the protein. The present study is the first to determine that the Ube3a protein ablation seen in the AS mouse model is also characteristic of AS patients and the silencing of the paternal UBE3A allele appears to be lifelong.