SHANK3 and Phelan-McDermid syndrome: Although genetically derived SHANK3 impairments have been associated to ASD pathology in general, their implication in the Phelan-McDermid syndrome, as well as evidence of its functional effects on connectivity patterns in the brain, similarly suggest that attentional deficits may be the most parsimonious explanation for some SHANK3-related ASD phenotypes in humans.