title: Clinical and mutation data in 12 patients with the clinical diagnosis of Nager syndrome.
abstract: Nager syndrome (MIM #154400) is the best-known preaxial acrofacial dysostosis, mainly characterized by craniofacial and preaxial limb anomalies. The craniofacial abnormalities mainly consist of downslanting palpebral fissures, malar hypoplasia, micrognathia, external ear anomalies, and cleft palate. The preaxial limb defects are characterized by radial and thumb hypoplasia or aplasia, duplication of thumbs and proximal radioulnar synostosis. Haploinsufficiency of SF3B4 (MIM *605593), which encodes SAP49, a component of the pre-mRNA spliceosomal complex, has recently been identified as the underlying cause of Nager syndrome. In our study, we performed exome sequencing in two and Sanger sequencing of SF3B4 in further ten previously unreported patients with the clinical diagnosis of Nager syndrome, including one familial case. We identified heterozygous SF3B4 mutations in seven out of twelve patients. Four of the seven mutations were shown to be de novo; in three individuals, DNA of both parents was not available. No familial mutations were discovered. Three mutations were nonsense, three were frameshift mutations and one T > C transition destroyed the translation start signal. In three of four SF3B4 negative families, EFTUD2 was analyzed, but no pathogenic variants were identified. Our results indicate that the SF3B4 gene is mutated in about half of the patients with the clinical diagnosis of Nager syndrome and further support genetic heterogeneity for this condition.
authors.affiliation: Institut für Humangenetik, Universitätsklinikum Essen, Universität Duisburg-Essen, Germany. christina.czeschik@uni-due.de
authors.forename: J C
authors.initials: JC
authors.lastname: Czeschik
authors.forename: C
authors.initials: C
authors.lastname: Voigt
authors.forename: Y
authors.initials: Y
authors.lastname: Alanay
authors.forename: B
authors.initials: B
authors.lastname: Albrecht
authors.forename: S
authors.initials: S
authors.lastname: Avci
authors.forename: D
authors.initials: D
authors.lastname: Fitzpatrick
authors.forename: D R
authors.initials: DR
authors.lastname: Goudie
authors.forename: U
authors.initials: U
authors.lastname: Hehr
authors.forename: A J
authors.initials: AJ
authors.lastname: Hoogeboom
authors.forename: H
authors.initials: H
authors.lastname: Kayserili
authors.forename: P O
authors.initials: PO
authors.lastname: Simsek-Kiper
authors.forename: L
authors.initials: L
authors.lastname: Klein-Hitpass
authors.forename: A
authors.initials: A
authors.lastname: Kuechler
authors.forename: V
authors.initials: V
authors.lastname: López-González
authors.forename: M
authors.initials: M
authors.lastname: Martin
authors.forename: S
authors.initials: S
authors.lastname: Rahmann
authors.forename: B
authors.initials: B
authors.lastname: Schweiger
authors.forename: M
authors.initials: M
authors.lastname: Splitt
authors.forename: B
authors.initials: B
authors.lastname: Wollnik
authors.forename: H-J
authors.initials: HJ
authors.lastname: Lüdecke
authors.forename: M
authors.initials: M
authors.lastname: Zeschnigk
authors.forename: D
authors.initials: D
authors.lastname: Wieczorek
mesh_terms: D000293:Adolescent; D000328:Adult; D002675:Child, Preschool; D059472:Exome / Q000235:genetics*; D005260:Female; D056726:Genetic Association Studies; D006801:Humans; D007223:Infant; D008297:Male; D008342:Mandibulofacial Dysostosis / Q000175:diagnosis / Q000235:genetics*; D009154:Mutation / Q000235:genetics*; D012322:RNA Precursors / Q000235:genetics*; D000072260:RNA Splicing Factors; D016601:RNA-Binding Proteins / Q000235:genetics*; D017381:Spliceosomes / Q000235:genetics*
chemical_list: D012322:RNA Precursors; D000072260:RNA Splicing Factors; D016601:RNA-Binding Proteins; C486347:SF3B4 protein, human