The role of the clock gene, per, in modulating high frequency oscillators in Drosophila, concerned with fine motor control and social timing (Kyriacou and Hall, 1980; Beaver and Giebultowicz, 2004), together with findings of genetic association of PER1 with autism, with and without LD (Nicholas et al., 2007; Neale et al., 2012; Yang et al., 2016), strengthens the notion that clock genes contribute to temporal deficits in autism. The gene discussed is PER1; the disease is autism.