title: BRF1 mutations alter RNA polymerase III-dependent transcription and cause neurodevelopmental anomalies.
abstract: RNA polymerase III (Pol III) synthesizes tRNAs and other small noncoding RNAs to regulate protein synthesis. Dysregulation of Pol III transcription has been linked to cancer, and germline mutations in genes encoding Pol III subunits or tRNA processing factors cause neurogenetic disorders in humans, such as hypomyelinating leukodystrophies and pontocerebellar hypoplasia. Here we describe an autosomal recessive disorder characterized by cerebellar hypoplasia and intellectual disability, as well as facial dysmorphic features, short stature, microcephaly, and dental anomalies. Whole-exome sequencing revealed biallelic missense alterations of BRF1 in three families. In support of the pathogenic potential of the discovered alleles, suppression or CRISPR-mediated deletion of brf1 in zebrafish embryos recapitulated key neurodevelopmental phenotypes; in vivo complementation showed all four candidate mutations to be pathogenic in an apparent isoform-specific context. BRF1 associates with BDP1 and TBP to form the transcription factor IIIB (TFIIIB), which recruits Pol III to target genes. We show that disease-causing mutations reduce Brf1 occupancy at tRNA target genes in Saccharomyces cerevisiae and impair cell growth. Moreover, BRF1 mutations reduce Pol III-related transcription activity in vitro. Taken together, our data show that BRF1 mutations that reduce protein activity cause neurodevelopmental anomalies, suggesting that BRF1-mediated Pol III transcription is required for normal cerebellar and cognitive development.
authors.affiliation: Institute of Human Genetics, University of Ulm, 89081 Ulm, Germany; guntram.borck@uni-ulm.de.
authors.forename: Guntram
authors.initials: G
authors.lastname: Borck
authors.affiliation: Gene Center Munich and Department of Biochemistry, Center for Integrated Protein Science CIPSM, Ludwig-Maximilians-Universität München, 81377 Munich, Germany;
authors.forename: Friederike
authors.initials: F
authors.lastname: Hög
authors.affiliation: Bambino Gesù Children's Hospital, IRCCS, 00165 Rome, Italy;
authors.forename: Maria Lisa
authors.initials: ML
authors.lastname: Dentici
authors.affiliation: Center for Human Disease Modeling, Duke University, Durham, North Carolina 27710, USA;
authors.forename: Perciliz L
authors.initials: PL
authors.lastname: Tan
authors.affiliation: Institute of Human Genetics, University of Ulm, 89081 Ulm, Germany;
authors.forename: Nadine
authors.initials: N
authors.lastname: Sowada
authors.affiliation: Serviço de Genética, Departamento de Pediatria, Hospital S. Maria, CHLN, 1649-035 Lisboa, Portugal;
authors.forename: Ana
authors.initials: A
authors.lastname: Medeira
authors.affiliation: Center for Integrative Genomics, University of Lausanne, 1015 Lausanne, Switzerland;
authors.forename: Lucie
authors.initials: L
authors.lastname: Gueneau
authors.affiliation: Cologne Center for Genomics (CCG), University of Cologne, 50931 Cologne, Germany;
authors.forename: Holger
authors.initials: H
authors.lastname: Thiele
authors.affiliation: Center for Human Disease Modeling, Duke University, Durham, North Carolina 27710, USA;
authors.forename: Maria
authors.initials: M
authors.lastname: Kousi
authors.affiliation: Bambino Gesù Children's Hospital, IRCCS, 00165 Rome, Italy;
authors.forename: Francesca
authors.initials: F
authors.lastname: Lepri
authors.affiliation: Gene Center Munich and Department of Biochemistry, Center for Integrated Protein Science CIPSM, Ludwig-Maximilians-Universität München, 81377 Munich, Germany;
authors.forename: Larissa
authors.initials: L
authors.lastname: Wenzeck
authors.affiliation: Molecular Neurogenetics Unit and Psychiatric and Neurodevelopmental Genetics Unit, Center for Human Genetic Research, Massachusetts General Hospital, Boston, Massachusetts 02114, USA;
authors.forename: Ian
authors.initials: I
authors.lastname: Blumenthal
authors.affiliation: Department of Experimental Medicine, Sapienza University, 00161 Rome, Italy;
authors.forename: Antonio
authors.initials: A
authors.lastname: Radicioni
authors.affiliation: Department of Neonatology, Sapienza University, 00161 Rome, Italy;
authors.forename: Tito Livio
authors.initials: TL
authors.lastname: Schwarzenberg
authors.affiliation: IRCCS Casa Sollievo Della Sofferenza, Medical Genetics Unit, 71013 San Giovanni Rotondo, Italy; PhD Program, Molecular Genetics applied to Medical Sciences, University of Brescia, 25121 Brescia, Italy;
authors.forename: Barbara
authors.initials: B
authors.lastname: Mandriani
authors.affiliation: U.O. Malattie Metaboliche PO Giovanni XXIII, AOU Policlinico Consorziale, 70120 Bari, Italy;
authors.forename: Rita
authors.initials: R
authors.lastname: Fischetto
authors.affiliation: Genomic Medicine, National Heart and Lung Institute, Imperial College, London SW3 6LY, United Kingdom;
authors.forename: Deborah J
authors.initials: DJ
authors.lastname: Morris-Rosendahl
authors.affiliation: Cologne Center for Genomics (CCG), University of Cologne, 50931 Cologne, Germany; Institute for Human Genetics, University of Cologne, 50931 Cologne, Germany;
authors.forename: Janine
authors.initials: J
authors.lastname: Altmüller
authors.affiliation: Center for Integrative Genomics, University of Lausanne, 1015 Lausanne, Switzerland;
authors.forename: Alexandre
authors.initials: A
authors.lastname: Reymond
authors.affiliation: Cologne Center for Genomics (CCG), University of Cologne, 50931 Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50674 Cologne, Germany; Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931 Cologne, Germany;
authors.forename: Peter
authors.initials: P
authors.lastname: Nürnberg
authors.affiliation: IRCCS Casa Sollievo Della Sofferenza, Medical Genetics Unit, 71013 San Giovanni Rotondo, Italy;
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Merla
authors.affiliation: Bambino Gesù Children's Hospital, IRCCS, 00165 Rome, Italy;
authors.forename: Bruno
authors.initials: B
authors.lastname: Dallapiccola
authors.affiliation: Center for Human Disease Modeling, Duke University, Durham, North Carolina 27710, USA;
authors.forename: Nicholas
authors.initials: N
authors.lastname: Katsanis
authors.affiliation: Max Planck Institute for Biophysical Chemistry, Department of Molecular Biology, 37077 Göttingen, Germany;
authors.forename: Patrick
authors.initials: P
authors.lastname: Cramer
authors.affiliation: Institute of Human Genetics, University of Ulm, 89081 Ulm, Germany; Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Kubisch
mesh_terms: D000015:Abnormalities, Multiple / Q000175:diagnosis / Q000235:genetics*; D000293:Adolescent; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D001921:Brain / Q000473:pathology; D049109:Cell Proliferation; D002648:Child; D002675:Child, Preschool; D059472:Exome; D019066:Facies; D005260:Female; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D007223:Infant; D008607:Intellectual Disability / Q000175:diagnosis / Q000235:genetics*; D008279:Magnetic Resonance Imaging; D008297:Male; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D010375:Pedigree; D010641:Phenotype; D011487:Protein Conformation; D020033:Protein Isoforms; D012320:RNA Polymerase III / Q000378:metabolism*; D035781:Siblings; D013577:Syndrome; D035381:TATA-Binding Protein Associated Factors / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic; D015027:Zebrafish
chemical_list: C441028:BRF1 protein, human; D020033:Protein Isoforms; D035381:TATA-Binding Protein Associated Factors; D012320:RNA Polymerase III