NRXN1 and autism: Initial studies using a mouse model for the human NRXN1 copy number variation (CNV) mutation, the Nrxn1α mouse knockout maintained on a mixed genetic background (C57BL6/SV129), found significant deficits in prepulse inhibition, a measure of sensorimotor gating, increased repetitive self-grooming behaviour, which has been proposed to model repetitive behavioural traits associated with autism, and impaired nest building behaviours that have been associated with altered social behaviour (Etherton et al., 2009).