The creatine (Cr) transporter (CrT, alias CRTR, MGC87396, CT1, SLC6A8, OMIM 300036) deficiency (CCDS1, OMIM #300352) is an X-linked inherited metabolic disorder characterized by cerebral Cr deficiency which results in intellectual disability, language and speech impairment, seizures and movement and behavioral disturbances, and affects about 1% of males with non- syndromic mental disability (van de Kampet al., 2014). Here, SLC6A8 is linked to Intellectual disability.