The pathophysiology of the Rett’s syndrome, a form of ASD with symptoms like impaired language skills, cognitive deficits, and stereotypic behavior (Chahrour and Zoghbi, 2007), can be traced back to a loss-of-function mutation of methyl-CpG-binding protein 2 (MECP2; Amir et al., 1999). The gene discussed is MECP2; the disease is Cognitive impairment.