UBE3A and microcephaly: Separate studies of AS/Ube3a+1 double mutants confirmed that a single Ube3aOE transgene copy was sufficient to restore UBE3A protein to WT levels in the brain (Supplemental Figure 5, A and B), fully rescuing increased female body weight, microcephaly, and impaired rotarod, marble burying, and nest building performance in AS littermate mice (Supplemental Figure 5, C–H).