SHANK3 and Phelan-McDermid syndrome: Estimates of the prevalence of ASD in patients with known abnormalities in the region of the SHANK3 gene (i.e., patients with 22q13 deletion syndrome or Phelan-McDermid Syndrome (PMS)) are conflicting with published studies reporting anywhere from 0–94 % depending on how the information was obtained [8–10].