Moreover, GTPase regulator associated with the focal adhesion kinase 1/Oligophrenin-1-like (GRAF1/OPHN-1-L), one of the gene showing altered expression level in ATRX, is potentially involved in Central Nervous System (CNS) function and in mental retardation and we report the identification of a novel alternative transcript and its tissue and brain distribution. The gene discussed is ARHGAP26; the disease is Intellectual disability.