Deep-intronic variants in CNGB3 cause achromatopsia by pseudoexon activation.
Por:
Weisschuh N, Sturm M, Baumann B, Audo I, Ayuso C, Bocquet B, Branham K, Brooks BP, Catalá-Mora J, Giorda R, Heckenlively JR, Hufnagel RB, Jacobson SG, Kellner U, Kitsiou-Tzeli S, Matet A, Martorell-Sampol L, Meunier I, Rudolph G, Sharon D, Stingl K, Streubel B, Varsányi B, Wissinger B and Kohl S
Publicada:
1 ene 2020
Ahead of Print:
30 sep 2019
Resumen:
Our comprehensive cohort of 1100 unrelated achromatopsia (ACHM) patients comprises a considerable number of cases (~5%) harboring only a single pathogenic variant in the major ACHM gene CNGB3. We sequenced the entire CNGB3 locus in 33 of these patients to find a second variant which eventually explained the patients' phenotype. Forty-seven intronic CNGB3 variants were identified in 28 subjects after a filtering step based on frequency and the exclusion of variants found in cis with pathogenic alleles. In a second step, in silico prediction tools were used to filter out those variants with little odds of being deleterious. This left three variants that were analyzed using heterologous splicing assays. Variant c.1663-1205G>A, found in 14 subjects, and variant c.1663-2137C>T, found in two subjects, were indeed shown to exert a splicing defect by causing pseudoexon insertion into the transcript. Subsequent screening of further unsolved CNGB3 subjects identified four additional cases harboring the c.1663-1205G>A variant which makes it the eighth most frequent CNGB3 variant in our cohort. Compound heterozygosity could be validated in ten cases. Our study demonstrates that whole gene sequencing can be a powerful approach to identify the second pathogenic allele in patients apparently harboring only one disease-causing variant.
Filiaciones:
Weisschuh N:
Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
Sturm M:
Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
Baumann B:
Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
Audo I:
Institut de la Vision, Sorbonne Université, INSERM, CNRS, Paris, France
CHNO des Quinze-Vingts, INSERM-DHOS CIC1423, Paris, France
Institute of Ophthalmology, University College of London, London, United Kingdom
Ayuso C:
Department of Genetics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD UAM), Madrid, Spain
Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
Bocquet B:
Centre National de Référence «Maladies Sensorielles Génétiques», Service Ophtalmologie, Hôpital Gui de Chauliac, CHRU de Montpellier, Montpellier, France
INSERM U1051, Institute for Neurosciences of Montpellier, Montpellier, France
Branham K:
Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan
Brooks BP:
National Eye Institute, National Institutes of Health, Bethesda, Maryland
Catalá-Mora J:
Ophthalmology, Hospital Sant Joan de Deu, Barcelona, Spain
Giorda R:
Molecular Biology Lab, Scientific Institute, IRCCS Eugenio Medea, Bosisio Parini, Italy
Heckenlively JR:
Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan
Hufnagel RB:
National Eye Institute, National Institutes of Health, Bethesda, Maryland
Jacobson SG:
Department of Ophthalmology, Perelman School of Medicine, Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania
Kellner U:
Rare Retinal Disease Center, Augenzentrum Siegburg, MVZ ADTC Siegburg GmbH, Siegburg, Germany
Kitsiou-Tzeli S:
Department of Medical Genetics, National Kapodistrian University of Athens, Athens, Greece
Matet A:
Department of Ophthalmology, Jules-Gonin Eye Hospital, University of Lausanne, Lausanne, Switzerland
Martorell-Sampol L:
Laboratorio de Genética Molecular, Hospital Sant Joan de Deu, Barcelona, Spain
Meunier I:
Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
Centre National de Référence «Maladies Sensorielles Génétiques», Service Ophtalmologie, Hôpital Gui de Chauliac, CHRU de Montpellier, Montpellier, France
Rudolph G:
Department of Ophthalmology, Ludwig-Maximilians-University, Munich, Germany
Sharon D:
Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
Stingl K:
University Eye Hospital, Center for Ophthalmology, University of Tübingen, Tübingen, Germany
Streubel B:
Department of Pathology, Medical University of Vienna, Vienna, Austria
Varsányi B:
Department of Ophthalmology, Semmelweis University, Budapest, Hungary
Department of Ophthalmology, University of Pécs Medical School, Pécs, Hungary
Wissinger B:
Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
Kohl S:
Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
Green Published, Green Accepted, gold
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