Rubinstein-Taybi syndrome (RTS) is characterized by symptoms of low intelligence, postnatal growth retardation with reduced final height, microcephaly and distinctive facial features, such as a deep hairline, broad, arched eyebrows, outwardly downward sloping eyes, base of the columella is below the nostrils when seen in profile, retrognathia and dental anomalies, additionally, broad, often radially angled thumbs and broad big toes are seen. When laughing, a characteristic facial expression with almost closed eyes can occur. Seizures occur frequently. Rubinstein-Taybi syndrome usually occurs sporadically, and the prevalence is estimated at approximately 1:100,000‑125,000.
One known cause of Rubinstein-Taybi syndrome is pathogenic variants in the CREBBP gene (approximately 50-70%), which codes for the cyclic AMP-regulated enhancer binding protein. In addition, pathogenic variants were described in the EP300 gene (approximately 5%), which codes for the E1A binding protein p300. These two proteins are transcriptional co-activators involved in many signaling pathways within the cell (e.g., DNA repair, growth, differentiation, apoptosis).
Korzus 2017, Adv Exp Med Biol 978:39 / Fergelot et al. 2016, Am J Med Genet A 170: 3069 / Milani et al. 2015, Pediatr 41:4 / Stevens et al. 2014, Gene reviews / Bartsch et al. 2010, Am J Med Genet 152A:181 / Schorry et al. 2008, Am J Med Genet 146A:2512