MECP2 and autism: An increased number of USVs has been detected also in other animal models of autism such as BTBR T+ tf/J, Shank2 −/− and Mecp2 null mice, Tsc1 +/− and Tsc1−/− conditional knockouts and mice with a chromosome 15q11–13 maternal deletion or a paternal duplication [37], [46], [60]–[64].