RSTS type 2 (RSTS2) is caused by pathogenic variants in EP300 and accounts for approximately 8%–10% of individuals with RSTS (Roelfsema et al., 2005; Negri et al., 2015; Fergelot et al., 2016; Stevens, 2019). Here, EP300 is linked to Rubinstein-Taybi syndrome due to CREBBP mutations.