Presynaptic electrophysiological function has been shown to be altered in MECP2 duplication mice (increased paired-pulse facilitation; Collins et al., 2004) and other autism mouse models (Deng et al., 2013), and mice with mutations in the proteins mediating presynaptic plasticity often demonstrate autistic features (Blundell et al., 2010). The gene discussed is MECP2; the disease is autism.