The most common diseases were Rubinstein-Taybi syndrome (CREBBP c.3292del, CREBBP c.6587_6588del, EP300 c.5961_5962del), Sotos syndrome (NSD1 c.2645C>G, NSD1 c.1492C>T (2 probands, monozygotic twin)), and DNMT3A-related disorders (DNMT3A c.1258A>T, DNMT3A c.1279G>T, and DNMT3A c.1012_1014+3del) in 3 probands, respectively. The gene discussed is EP300; the disease is Rubinstein-Taybi syndrome.