Zinc deficiency has been observed in humans affected not only by ASD, but also in Phelan-McDermid syndrome in which heterozygous loss of SHANK3 occurs (Faber et al., 2009; Yasuda et al., 2011; Grabrucker et al., 2014; Pfaender et al., 2017). Here, SHANK3 is linked to Phelan-McDermid syndrome.