CREBBP and Rubinstein-Taybi syndrome: Truncating mutations in SRCAP, which is an SNF2-related chromatin-remodeling factor that serves as a coactivator for CREB-binding protein (CREBBP, better known as CBP, the major cause of Rubinstein-Taybi syndrome [RTS]) had been reported as causal, and the majority of mutations occurred between codon 2407 and 2517 in exon 34 resulting in loss of three C-terminal AT-hook motifs [7, 12].