Modified ube3a gene for a gene therapy approach for angelman syndrome

Abstract

Angelman Syndrome (AS) is a genetic disorder occurring in approximately one in every 15,000 births. It is characterized by severe mental retardation, seizures, difficulty speaking and ataxia. The gene responsible for AS was discovered to be UBE3A and encodes for E6-AP, an ubiquitin ligase. A unique feature of this gene is that it undergoes maternal imprinting in a neuron-specific manner. In the majority of AS cases, there is a mutation or deletion in the maternally inherited UBE3A gene, although other cases are the result of uniparental disomy or mismethylation of the maternal gene. While most human disorders characterized by severe mental retardation involve abnormalities in brain structure, no gross anatomical changes are associated with AS. We have generated a Ube3a protein with additional sequences that should allow the secretion from cells and uptake by neighboring neuronal cells. This would confer a functional E6-AP protein into the neurons and rescue disease pathology.