CREBBP and Rubinstein-Taybi syndrome: The pathogenesis of RSTS was found to be associated with two highly evolutionarily conserved genes, and depending on the pathogenic genes, RSTS can be classified into RSTS1 (RSTS1, NM_004380.3) due to CREBBP gene variants and RSTS2 (RSTS2, NM_001429.4) due to EP300 gene variant.