In our cohort of six patients with typically clinical features of RSTS, five were found having mutations of CREBBP gene, and the patient 6 had a microdeletion found by CGH array, including exons 20 to 31 of CREBBP gene, with a mosaicism estimated between 35% and 50%. The gene discussed is CREBBP; the disease is Rubinstein-Taybi syndrome.