UBE3A (Ubiquitin Protein Ligase E3A): UBE3A is a gene that encodes an E3 ubiquitin ligase enzyme, which helps regulate protein degradation via the ubiquitinâproteasome pathway. It plays a crucial role in normal brain development and function. Mutations in UBE3A are associated with Angelman syndrome, a neurodevelopmental disorder characterised by intellectual disability, developmental delay, and distinctive behavioural features.