Mutations in protocadherin 19 (PCDH19) chromosome X-linked gene, leads to Epilepsy in Females with Mental Retardation (EFMR) disease, cognitive impairments, and autistic phenotype (Ryan et al., 1997; Dibbens et al., 2008; Hynes et al., 2010; Specchio et al., 2011). The gene discussed is PCDH19; the disease is Cognitive impairment.