title: Two patients with EP300 mutations and facial dysmorphism different from the classic Rubinstein-Taybi syndrome.
abstract: Rubinstein-Taybi syndrome (RTS) is characterized by mental retardation, broad thumbs and great toes and a recognizable craniofacial phenotype. Causative mutations have been described in the CREBBP and EP300 genes. Here we present a 19-year-old woman and an unrelated 3-year-old boy, both with broad thumbs and halluces, but with facial aspects distinct from those of typical RTS. The woman had a marked learning disability, but no mental retardation. We identified a de novo c.7100delC mutation in EP300 (which predicts p.P2366RfsX35) in the woman and an apparently de novo c.638delG mutation in the boy, which predicts p.G213EfsX6. Mutations in EP300 are a known but rare cause of RTS. Only five other patients have been reported. We propose that individuals with EP300 mutations may exhibit a slightly different phenotype compared to individuals with CREBBP mutations, with milder cognitive impairment, more pronounced microcephaly, absent or mild downslanting of palpebral fissures, distinct arched eyebrows, and greater degree of retrognathia.
authors.affiliation: Institut für Humangenetik, Universitätsmedizin der Johannes Gutenberg-Universität Mainz, Langenbeckstrasse 1, D-55131 Mainz, Germany. bartsch@humgen.klinik.uni-mainz.de
authors.forename: Oliver
authors.initials: O
authors.lastname: Bartsch
authors.forename: Janette
authors.initials: J
authors.lastname: Labonté
authors.forename: Beate
authors.initials: B
authors.lastname: Albrecht
authors.forename: Dagmar
authors.initials: D
authors.lastname: Wieczorek
authors.forename: Stanislav
authors.initials: S
authors.lastname: Lechno
authors.forename: Ulrich
authors.initials: U
authors.lastname: Zechner
authors.forename: Thomas
authors.initials: T
authors.lastname: Haaf
mesh_terms: D000328:Adult; D002675:Child, Preschool; D050881:E1A-Associated p300 Protein / Q000235:genetics*; D005260:Female; D006801:Humans; D008297:Male; D009154:Mutation; D012415:Rubinstein-Taybi Syndrome / Q000235:genetics*
chemical_list: D050881:E1A-Associated p300 Protein; C494360:EP300 protein, human