51
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Revision of RUNX1 Variant Curation Rules. Blood Adv 2022; 6:4726-4730. [PMID: 35764482 DOI: 10.1182/bloodadvances.2022008017] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 06/27/2022] [Indexed: 11/20/2022] Open
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52
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Sharkov A, Sparber P, Stepanova A, Pyankov D, Korostelev S, Skoblov M. Case Report: Phenotype-Driven Diagnosis of Atypical Dravet-Like Syndrome Caused by a Novel Splicing Variant in the SCN2A Gene. Front Genet 2022; 13:888481. [PMID: 35711923 PMCID: PMC9194094 DOI: 10.3389/fgene.2022.888481] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 04/19/2022] [Indexed: 01/18/2023] Open
Abstract
Febrile-associated epileptic encephalopathy is a large genetically heterogeneous group that is associated with pathogenic variants in SCN1A, PCDH19, SCN2A, SCN8A, and other genes. The disease onset ranges from neonatal or early-onset epileptic encephalopathy to late-onset epilepsy after 18 months. Some etiology-specific epileptic encephalopathies have target therapy which can serve as a clue for the correct genetic diagnosis. We present genetic, clinical, electroencephalographic, and behavioral features of a 4-year-old girl with epileptic encephalopathy related to a de novo intronic variant in the SCN2A gene. Initial NGS analysis revealed a frameshift variant in the KDM6A gene and a previously reported missense variant in SCN1A. Due to lack of typical clinical signs of Kabuki syndrome, we performed X-chromosome inactivation that revealed nearly complete skewed inactivation. Segregation analysis showed that the SCN1A variant was inherited from a healthy father. The proband had resistance to multiple antiseizure medications but responded well to sodium channel inhibitor Carbamazepine. Reanalysis of NGS data by a neurogeneticist revealed a previously uncharacterized heterozygous variant c.1035-7A>G in the SCN2A gene. Minigene assay showed that the c.1035-7A>G variant activates a cryptic intronic acceptor site which leads to 6-nucleotide extension of exon 9 (NP_066287.2:p.(Gly345_Gln346insTyrSer). SCN2A encephalopathy is a recognizable severe phenotype. Its electro-clinical and treatment response features can serve as a hallmark. In such a patient, reanalysis of genetic data is strongly recommended in case of negative or conflicting results of DNA analysis.
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Affiliation(s)
- Artem Sharkov
- Genomed Ltd., Moscow, Russia.,Veltischev Research and Clinical Institute for Pediatrics of the Pirogov Russian National Research Medical University, Moscow, Russia
| | - Peter Sparber
- Research Centre for Medical Genetics, Moscow, Russia
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53
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Torrado M, Maneiro E, Lamounier Junior A, Fernández-Burriel M, Sánchez Giralt S, Martínez-Carapeto A, Cazón L, Santiago E, Ochoa JP, McKenna WJ, Santomé L, Monserrat L. Identification of an elusive spliceogenic MYBPC3 variant in an otherwise genotype-negative hypertrophic cardiomyopathy pedigree. Sci Rep 2022; 12:7284. [PMID: 35508642 PMCID: PMC9068804 DOI: 10.1038/s41598-022-11159-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 04/13/2022] [Indexed: 11/10/2022] Open
Abstract
The finding of a genotype-negative hypertrophic cardiomyopathy (HCM) pedigree with several affected members indicating a familial origin of the disease has driven this study to discover causative gene variants. Genetic testing of the proband and subsequent family screening revealed the presence of a rare variant in the MYBPC3 gene, c.3331−26T>G in intron 30, with evidence supporting cosegregation with the disease in the family. An analysis of potential splice-altering activity using several splicing algorithms consistently yielded low scores. Minigene expression analysis at the mRNA and protein levels revealed that c.3331−26T>G is a spliceogenic variant with major splice-altering activity leading to undetectable levels of properly spliced transcripts or the corresponding protein. Minigene and patient mRNA analyses indicated that this variant induces complete and partial retention of intron 30, which was expected to lead to haploinsufficiency in carrier patients. As most spliceogenic MYBPC3 variants, c.3331−26T>G appears to be non-recurrent, since it was identified in only two additional unrelated probands in our large HCM cohort. In fact, the frequency analysis of 46 known splice-altering MYBPC3 intronic nucleotide substitutions in our HCM cohort revealed 9 recurrent and 16 non-recurrent variants present in a few probands (≤ 4), while 21 were not detected. The identification of non-recurrent elusive MYBPC3 spliceogenic variants that escape detection by in silico algorithms represents a challenge for genetic diagnosis of HCM and contributes to solving a fraction of genotype-negative HCM cases.
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Affiliation(s)
- Mario Torrado
- Cardiovascular Research Group, University of A Coruña, Campus de Oza, Building Fortín, 15006, A Coruña, Spain. .,Biomedical Research Institute of A Coruña, A Coruña, Spain.
| | - Emilia Maneiro
- Biomedical Research Institute of A Coruña, A Coruña, Spain. .,Cardiovascular Genetics, Health in Code, Business Center Marineda, Avenida de Arteixo 43, Local 1A, 15008, A Coruña, Spain.
| | - Arsonval Lamounier Junior
- Cardiovascular Research Group, University of A Coruña, Campus de Oza, Building Fortín, 15006, A Coruña, Spain.,Biomedical Research Institute of A Coruña, A Coruña, Spain.,Cardiovascular Genetics, Health in Code, Business Center Marineda, Avenida de Arteixo 43, Local 1A, 15008, A Coruña, Spain.,Medical School, Universidade Vale do Rio Doce, Governador Valadares, MG, Brazil
| | | | | | | | - Laura Cazón
- Cardiovascular Genetics, Health in Code, Business Center Marineda, Avenida de Arteixo 43, Local 1A, 15008, A Coruña, Spain
| | - Elisa Santiago
- Cardiovascular Genetics, Health in Code, Business Center Marineda, Avenida de Arteixo 43, Local 1A, 15008, A Coruña, Spain
| | - Juan Pablo Ochoa
- Biomedical Research Institute of A Coruña, A Coruña, Spain.,Cardiovascular Genetics, Health in Code, Business Center Marineda, Avenida de Arteixo 43, Local 1A, 15008, A Coruña, Spain
| | - William J McKenna
- Cardiovascular Research Group, University of A Coruña, Campus de Oza, Building Fortín, 15006, A Coruña, Spain.,Biomedical Research Institute of A Coruña, A Coruña, Spain.,Institute of Cardiovascular Science, University College London, London, UK
| | - Luis Santomé
- Cardiovascular Genetics, Health in Code, Business Center Marineda, Avenida de Arteixo 43, Local 1A, 15008, A Coruña, Spain
| | - Lorenzo Monserrat
- Biomedical Research Institute of A Coruña, A Coruña, Spain.,Cardiovascular Genetics, Health in Code, Business Center Marineda, Avenida de Arteixo 43, Local 1A, 15008, A Coruña, Spain
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54
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Affiliation(s)
- John W Henson
- Hereditary Cancer Clinic, Medical College of Georgia, Augusta University Health, Augusta
- Georgia Cancer Center, Medical College of Georgia, Augusta University Health, Augusta
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55
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Gu H, Hong J, Lee W, Kim SB, Chun S, Min WK. RNA Sequencing for Elucidating an Intronic Variant of Uncertain Significance ( SDHD c.314+3A>T) in Splicing Site Consensus Sequences. Ann Lab Med 2022; 42:376-379. [PMID: 34907111 PMCID: PMC8677484 DOI: 10.3343/alm.2022.42.3.376] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 09/02/2021] [Accepted: 11/29/2021] [Indexed: 11/19/2022] Open
Affiliation(s)
- Hyunjung Gu
- Department of Laboratory Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Jinyoung Hong
- Department of Laboratory Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Woochang Lee
- Department of Laboratory Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Sung-Bae Kim
- Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Sail Chun
- Department of Laboratory Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Won-Ki Min
- Department of Laboratory Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
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56
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Feurstein S, Hahn CN, Mehta N, Godley LA. A practical guide to interpreting germline variants that drive hematopoietic malignancies, bone marrow failure, and chronic cytopenias. Genet Med 2022; 24:931-954. [PMID: 35063349 DOI: 10.1016/j.gim.2021.12.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 12/14/2021] [Indexed: 10/19/2022] Open
Abstract
PURPOSE The American College of Medical Genetics and Genomics and the Association for Molecular Pathology guidelines for germline variant interpretation are implemented as a broad framework by standardizing variant interpretation. These rules were designed to be specified, but this process has not been performed for most of the 200 genes associated with inherited hematopoietic malignancies, bone marrow failure, and cytopenias. Because guidelines on how to perform these gene specifications are lacking, variant interpretation is less reliable and reproducible. METHODS We have used a variety of methods such as calculations of minor allele frequencies, quasi-case-control studies to establish thresholds, proband counting, and plotting of receiver operating characteristic curves to compare different in silico prediction tools to design recommendations for variant interpretation. RESULTS We herein provide practical recommendations for the creation of thresholds for minor allele frequencies, in silico predictions, counting of probands, identification of functional domains with minimal benign variation, use of constraint Z-scores and functional evidence, prediction of nonsense-mediated decay, and assessment of phenotype specificity. CONCLUSION These guidelines can be used by anyone interpreting variants associated with inherited hematopoietic malignancies, bone marrow failure, and cytopenias to develop criteria for reliable, accurate, and reproducible germline variant interpretation.
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Affiliation(s)
- Simone Feurstein
- Section of Hematology/Oncology, Department of Medicine, The University of Chicago, Chicago, IL; Section of Hematology, Oncology and Rheumatology, Department of Internal Medicine, Heidelberg University Hospital, Heidelberg, Germany
| | - Christopher N Hahn
- Molecular Pathology Research Laboratory, Centre for Cancer Biology, SA Pathology and University of South Australia, Adelaide, South Australia, Australia; Adelaide Medical School, The University of Adelaide, Adelaide, South Australia, Australia
| | - Nikita Mehta
- Diagnostic Molecular Genetics Laboratory, Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY
| | - Lucy A Godley
- Section of Hematology/Oncology, Department of Medicine, The University of Chicago, Chicago, IL; Department of Human Genetics, The University of Chicago, Chicago, IL.
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57
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Possible Catch-Up Developmental Trajectories for Children with Mild Developmental Delay Caused by NAA15 Pathogenic Variants. Genes (Basel) 2022; 13:genes13030536. [PMID: 35328089 PMCID: PMC8954815 DOI: 10.3390/genes13030536] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 03/16/2022] [Accepted: 03/16/2022] [Indexed: 02/04/2023] Open
Abstract
Variants in NAA15 are closely related to neurodevelopmental disorders (NDDs). In this study, we investigated the spectrum and clinical features of NAA15 variants in a Chinese NDD cohort of 769 children. Four novel NAA15 pathogenic variants were detected by whole-exome sequencing, including three de novo variants and one maternal variant. The in vitro minigene splicing assay confirmed one noncanonical splicing variant (c.1410+5G>C), which resulted in abnormal mRNA splicing. All affected children presented mild developmental delay, and catch-up trajectories were noted in three patients based on their developmental scores at different ages. Meanwhile, the literature review also showed that half of the reported patients with NAA15 variants presented mild/moderate developmental delay or intellectual disability, and possible catch-up sign was indicated for three affected patients. Taken together, our study expanded the spectrum of NAA15 variants in NDD patients. The affected patients presented mild developmental delay, and possible catch-up developmental trajectories were suggested. Studying the natural neurodevelopmental trajectories of NDD patients with pathogenic variants and their benefits from physical rehabilitations are needed in the future for precise genetic counseling and clinical management.
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58
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He WB, Xiao WJ, Dai CL, Wang YR, Li XR, Gong F, Meng LL, Tan C, Zeng SC, Lu GX, Lin G, Tan YQ, Hu H, Du J. RNA splicing analysis contributes to reclassifying variants of uncertain significance and improves the diagnosis of monogenic disorders. J Med Genet 2022; 59:1010-1016. [PMID: 35121647 DOI: 10.1136/jmedgenet-2021-108013] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 01/06/2022] [Indexed: 11/04/2022]
Abstract
BACKGROUND Numerous variants of uncertain significance (VUSs) have been identified by whole exome sequencing in clinical practice. However, VUSs are not currently considered medically actionable. OBJECTIVE To assess the splicing patterns of 49 VUSs in 48 families identified clinically to improve genetic counselling and family planning. METHODS Forty-nine participants with 49 VUSs were recruited from the Reproductive and Genetic Hospital of CITIC-Xiangya. Bioinformatic analysis was performed to preliminarily predict the splicing effects of these VUSs. RT-PCR and minigene analysis were used to assess the splicing patterns of the VUSs. According to the results obtained, couples opted for different methods of reproductive interventions to conceive a child, including prenatal diagnosis and preimplantation genetic testing (PGT). RESULTS Eleven variants were found to alter pre-mRNA splicing and one variant caused nonsense-mediated mRNA decay, which resulted in the reclassification of these VUSs as likely pathogenic. One couple chose to undergo in vitro fertilisation with PGT treatment; a healthy embryo was transferred and the pregnancy is ongoing. Three couples opted for natural pregnancy with prenatal diagnosis. One couple terminated the pregnancy because the fetus was affected by short-rib thoracic dysplasia and harboured the related variant. The infants of the other two couples were born and were healthy at their last recorded follow-up. CONCLUSION RNA splicing analysis is an important method to assess the impact of sequence variants on splicing in clinical practice and can contribute to the reclassification of a significant proportion of VUSs. RNA splicing analysis should be considered for genetic disease diagnostics.
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Affiliation(s)
- Wen-Bin He
- Institute of Reproductive and Stem Cell Engineering, School of Basic Medical Science, Central South University, Changsha, Hunan, China.,National Engineering and Research Center of Human Stem Cells, Changsha, Hunan, China.,Reproductive and Genetic Hospital of CITIC-Xiangya, Changsha, Hunan, China.,Clinical Research Center For Reproduction and Genetics In Hunan Province, Changsha, China
| | - Wen-Juan Xiao
- National Engineering and Research Center of Human Stem Cells, Changsha, Hunan, China.,Hunan Guangxiu Hospital, Medical College of Hunan Normal University, Changsha, Hunan, China
| | - Cong-Ling Dai
- Institute of Reproductive and Stem Cell Engineering, School of Basic Medical Science, Central South University, Changsha, Hunan, China.,National Engineering and Research Center of Human Stem Cells, Changsha, Hunan, China.,Reproductive and Genetic Hospital of CITIC-Xiangya, Changsha, Hunan, China.,Clinical Research Center For Reproduction and Genetics In Hunan Province, Changsha, China
| | - Yu-Rong Wang
- Hunan Guangxiu Hospital, Medical College of Hunan Normal University, Changsha, Hunan, China
| | - Xiu-Rong Li
- Reproductive and Genetic Hospital of CITIC-Xiangya, Changsha, Hunan, China.,Clinical Research Center For Reproduction and Genetics In Hunan Province, Changsha, China
| | - Fei Gong
- Institute of Reproductive and Stem Cell Engineering, School of Basic Medical Science, Central South University, Changsha, Hunan, China.,National Engineering and Research Center of Human Stem Cells, Changsha, Hunan, China.,Reproductive and Genetic Hospital of CITIC-Xiangya, Changsha, Hunan, China.,Clinical Research Center For Reproduction and Genetics In Hunan Province, Changsha, China
| | - Lan-Lan Meng
- Institute of Reproductive and Stem Cell Engineering, School of Basic Medical Science, Central South University, Changsha, Hunan, China.,Reproductive and Genetic Hospital of CITIC-Xiangya, Changsha, Hunan, China
| | - Chen Tan
- Institute of Reproductive and Stem Cell Engineering, School of Basic Medical Science, Central South University, Changsha, Hunan, China
| | - Si-Cong Zeng
- Reproductive and Genetic Hospital of CITIC-Xiangya, Changsha, Hunan, China.,Hunan Guangxiu Hospital, Medical College of Hunan Normal University, Changsha, Hunan, China
| | - Guang-Xiu Lu
- National Engineering and Research Center of Human Stem Cells, Changsha, Hunan, China.,Reproductive and Genetic Hospital of CITIC-Xiangya, Changsha, Hunan, China.,Clinical Research Center For Reproduction and Genetics In Hunan Province, Changsha, China.,Hunan Guangxiu Hospital, Medical College of Hunan Normal University, Changsha, Hunan, China
| | - Ge Lin
- Institute of Reproductive and Stem Cell Engineering, School of Basic Medical Science, Central South University, Changsha, Hunan, China.,National Engineering and Research Center of Human Stem Cells, Changsha, Hunan, China.,Reproductive and Genetic Hospital of CITIC-Xiangya, Changsha, Hunan, China.,Clinical Research Center For Reproduction and Genetics In Hunan Province, Changsha, China
| | - Yue-Qiu Tan
- Institute of Reproductive and Stem Cell Engineering, School of Basic Medical Science, Central South University, Changsha, Hunan, China.,National Engineering and Research Center of Human Stem Cells, Changsha, Hunan, China.,Reproductive and Genetic Hospital of CITIC-Xiangya, Changsha, Hunan, China.,Clinical Research Center For Reproduction and Genetics In Hunan Province, Changsha, China.,Hunan Guangxiu Hospital, Medical College of Hunan Normal University, Changsha, Hunan, China
| | - Hao Hu
- Reproductive and Genetic Hospital of CITIC-Xiangya, Changsha, Hunan, China .,Clinical Research Center For Reproduction and Genetics In Hunan Province, Changsha, China
| | - Juan Du
- Institute of Reproductive and Stem Cell Engineering, School of Basic Medical Science, Central South University, Changsha, Hunan, China .,National Engineering and Research Center of Human Stem Cells, Changsha, Hunan, China.,Reproductive and Genetic Hospital of CITIC-Xiangya, Changsha, Hunan, China.,Clinical Research Center For Reproduction and Genetics In Hunan Province, Changsha, China
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59
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Rowlands CF, Taylor A, Rice G, Whiffin N, Hall HN, Newman WG, Black GCM, O'Keefe RT, Hubbard S, Douglas AGL, Baralle D, Briggs TA, Ellingford JM. MRSD: A quantitative approach for assessing suitability of RNA-seq in the investigation of mis-splicing in Mendelian disease. Am J Hum Genet 2022; 109:210-222. [PMID: 35065709 PMCID: PMC8874219 DOI: 10.1016/j.ajhg.2021.12.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 12/12/2021] [Indexed: 12/16/2022] Open
Abstract
Variable levels of gene expression between tissues complicates the use of RNA sequencing of patient biosamples to delineate the impact of genomic variants. Here, we describe a gene- and tissue-specific metric to inform the feasibility of RNA sequencing. This overcomes limitations of using expression values alone as a metric to predict RNA-sequencing utility. We have derived a metric, minimum required sequencing depth (MRSD), that estimates the depth of sequencing required from RNA sequencing to achieve user-specified sequencing coverage of a gene, transcript, or group of genes. We applied MRSD across four human biosamples: whole blood, lymphoblastoid cell lines (LCLs), skeletal muscle, and cultured fibroblasts. MRSD has high precision (90.1%-98.2%) and overcomes transcript region-specific sequencing biases. Applying MRSD scoring to established disease gene panels shows that fibroblasts, of these four biosamples, are the optimum source of RNA for 63.1% of gene panels. Using this approach, up to 67.8% of the variants of uncertain significance in ClinVar that are predicted to impact splicing could be assayed by RNA sequencing in at least one of the biosamples. We demonstrate the utility and benefits of MRSD as a metric to inform functional assessment of splicing aberrations, in particular in the context of Mendelian genetic disorders to improve diagnostic yield.
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Affiliation(s)
- Charlie F Rowlands
- Division of Evolution, Infection and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PT, UK; Manchester Centre for Genomic Medicine, St Mary's Hospital, Manchester University NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester M13 9WL, UK
| | - Algy Taylor
- Manchester Centre for Genomic Medicine, St Mary's Hospital, Manchester University NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester M13 9WL, UK
| | - Gillian Rice
- Division of Evolution, Infection and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PT, UK
| | - Nicola Whiffin
- Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Hildegard Nikki Hall
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - William G Newman
- Division of Evolution, Infection and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PT, UK; Manchester Centre for Genomic Medicine, St Mary's Hospital, Manchester University NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester M13 9WL, UK
| | - Graeme C M Black
- Division of Evolution, Infection and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PT, UK; Manchester Centre for Genomic Medicine, St Mary's Hospital, Manchester University NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester M13 9WL, UK
| | - Raymond T O'Keefe
- Division of Evolution, Infection and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PT, UK
| | - Simon Hubbard
- Division of Evolution, Infection and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PT, UK
| | - Andrew G L Douglas
- Wessex Clinical Genetics Service, Princess Anne Hospital, University Hospital Southampton NHS Foundation Trust, Coxford Rd, Southampton SO16 5YA, UK; Faculty of Medicine, University of Southampton, Duthie Building, Southampton General Hospital, Tremona Road, Southampton SO16 6YD, UK
| | - Diana Baralle
- Wessex Clinical Genetics Service, Princess Anne Hospital, University Hospital Southampton NHS Foundation Trust, Coxford Rd, Southampton SO16 5YA, UK; Faculty of Medicine, University of Southampton, Duthie Building, Southampton General Hospital, Tremona Road, Southampton SO16 6YD, UK
| | - Tracy A Briggs
- Division of Evolution, Infection and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PT, UK; Manchester Centre for Genomic Medicine, St Mary's Hospital, Manchester University NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester M13 9WL, UK
| | - Jamie M Ellingford
- Division of Evolution, Infection and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PT, UK; Manchester Centre for Genomic Medicine, St Mary's Hospital, Manchester University NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester M13 9WL, UK.
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60
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Canson DM, Dumenil T, Parsons MT, O'Mara TA, Davidson AL, Okano S, Signal B, Mercer TR, Glubb DM, Spurdle AB. The splicing effect of variants at branchpoint elements in cancer genes. Genet Med 2022; 24:398-409. [PMID: 34906448 DOI: 10.1016/j.gim.2021.09.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 08/24/2021] [Accepted: 09/27/2021] [Indexed: 01/09/2023] Open
Abstract
PURPOSE Branchpoint elements are required for intron removal, and variants at these elements can result in aberrant splicing. We aimed to assess the value of branchpoint annotations generated from recent large-scale studies to select branchpoint-abrogating variants, using hereditary cancer genes as model. METHODS We identified branchpoint elements in 119 genes associated with hereditary cancer from 3 genome-wide experimentally-inferred and 2 predicted branchpoint data sets. We then identified variants that occur within branchpoint elements from public databases. We compared conservation, unique variant observations, and population frequencies at different nucleotides within branchpoint motifs. Finally, selected minigene assays were performed to assess the splicing effect of variants at branchpoint elements within mismatch repair genes. RESULTS There was poor overlap between predicted and experimentally-inferred branchpoints. Our analysis of cancer genes suggested that variants at -2 nucleotide, -1 nucleotide, and branchpoint positions in experimentally-inferred canonical motifs are more likely to be clinically relevant. Minigene assay data showed the -2 nucleotide to be more important to branchpoint motif integrity but also showed fluidity in branchpoint usage. CONCLUSION Data from cancer gene analysis suggest that there are few high-risk alleles that severely impact function via branchpoint abrogation. Results of this study inform a general scheme to prioritize branchpoint motif variants for further study.
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Affiliation(s)
- Daffodil M Canson
- Genetics and Computational Biology, QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia; Faculty of Medicine, The University of Queensland, Brisbane, Queensland, Australia
| | - Troy Dumenil
- Immunology, QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Michael T Parsons
- Genetics and Computational Biology, QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Tracy A O'Mara
- Genetics and Computational Biology, QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Aimee L Davidson
- Genetics and Computational Biology, QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia; Faculty of Medicine, The University of Queensland, Brisbane, Queensland, Australia
| | - Satomi Okano
- Statistics, QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Bethany Signal
- Genomics and Epigenetics, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
| | - Tim R Mercer
- Genomics and Epigenetics, Garvan Institute of Medical Research, Sydney, New South Wales, Australia; Australian Institute of Bioengineering and Nanotechnology, The University of Queensland, Brisbane, Queensland, Australia
| | - Dylan M Glubb
- Genetics and Computational Biology, QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Amanda B Spurdle
- Genetics and Computational Biology, QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia; Faculty of Medicine, The University of Queensland, Brisbane, Queensland, Australia.
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61
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Restivo C, Le Bras M, Deguigne P, Le Glatin L, Guerry C, Férec C, Le Maréchal C, Beloeil R, Fichou Y. The novel c.634+
4A
>G splicing variant in
RHCE
results in weak C and e antigen expression in a pregnant woman originated from Japan. Transfusion 2022; 62:758-763. [DOI: 10.1111/trf.16811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 01/03/2022] [Accepted: 01/12/2022] [Indexed: 11/28/2022]
Affiliation(s)
- Cynthia Restivo
- Univ Brest, Inserm, EFS, UMR1078, GGB Brest France
- Laboratory of Excellence GR‐Ex Paris France
| | - Myriam Le Bras
- Laboratoire d'Immuno‐Hématologie Etablissement français du sang (EFS) Centre – Pays de la Loire Angers France
| | - Pierre‐Antoine Deguigne
- Laboratoire d'Immuno‐Hématologie Etablissement français du sang (EFS) Centre – Pays de la Loire Angers France
| | - Laurence Le Glatin
- Laboratoire de Biologie Moléculaire des Groupes Sanguins (LBMGS), EFS Bretagne Brest France
| | - Christine Guerry
- Laboratoire de Biologie Moléculaire des Groupes Sanguins (LBMGS), EFS Bretagne Brest France
| | - Claude Férec
- Univ Brest, Inserm, EFS, UMR1078, GGB Brest France
- Service de Génétique Médicale, CHRU Brest Brest France
| | - Cédric Le Maréchal
- Univ Brest, Inserm, EFS, UMR1078, GGB Brest France
- Laboratoire de Biologie Moléculaire des Groupes Sanguins (LBMGS), EFS Bretagne Brest France
- Service de Génétique Médicale, CHRU Brest Brest France
| | - Rémi Beloeil
- Laboratoire de Biologie Moléculaire des Groupes Sanguins (LBMGS), EFS Bretagne Brest France
| | - Yann Fichou
- Univ Brest, Inserm, EFS, UMR1078, GGB Brest France
- Laboratory of Excellence GR‐Ex Paris France
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Murdock DR, Rosenfeld JA, Lee B. What Has the Undiagnosed Diseases Network Taught Us About the Clinical Applications of Genomic Testing? Annu Rev Med 2022; 73:575-585. [PMID: 35084988 PMCID: PMC10874501 DOI: 10.1146/annurev-med-042120-014904] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Genetic testing has undergone a revolution in the last decade, particularly with the advent of next-generation sequencing and its associated reductions in costs and increases in efficiencies. The Undiagnosed Diseases Network (UDN) has been a leader in the application of such genomic testing for rare disease diagnosis. This review discusses the current state of genomic testing performed within the UDN, with a focus on the strengths and limitations of whole-exome and whole-genome sequencing in clinical diagnostics and the importance of ongoing data reanalysis. The role of emerging technologies such as RNA and long-read sequencing to further improve diagnostic rates in the UDN is also described. This review concludes with a discussion of the challenges faced in insurance coverage of comprehensive genomic testing as well as the opportunities for a larger role of testing in clinical medicine.
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Affiliation(s)
- David R Murdock
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA;
| | - Jill A Rosenfeld
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA;
| | - Brendan Lee
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA;
- Texas Children's Hospital, Houston, Texas 77030, USA
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63
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Hiraide T, Shimizu K, Miyamoto S, Aoto K, Nakashima M, Yamaguchi T, Kosho T, Ogata T, Saitsu H. Genome sequencing and RNA sequencing of urinary cells reveal an intronic FBN1 variant causing aberrant splicing. J Hum Genet 2022; 67:387-392. [DOI: 10.1038/s10038-022-01016-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 12/28/2021] [Accepted: 01/13/2022] [Indexed: 11/09/2022]
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64
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Duan J, Ye Y, Hu Z, Zhao X, Liao J, Chen L. Identification of a Novel Canonical Splice Site Variant TSC2 c.2967-1G>T That is Not Associated With Tuberous Sclerosis Pathogenesis. Front Genet 2022; 13:904224. [PMID: 35692821 PMCID: PMC9184681 DOI: 10.3389/fgene.2022.904224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 05/16/2022] [Indexed: 11/27/2022] Open
Abstract
Tuberous sclerosis, also known as tuberous sclerosis complex (TSC), is an autosomal dominant defect characterized by hamartomas in multiple organ systems. Inactivating variants cause this defect in either the TSC1 gene or the TSC2 gene, leading to hamartin or tuberin protein dysfunction, thus resulting in TSC. The diagnostic criteria for TSC suggest that it can be diagnosed by identifying a heterozygous pathogenic variant of TSC1 or TSC2, even in the absence of clinical signs. In a 4-year-old girl, we identified a splicing variant (NM_000548.4: c.2967-1G>T) that she inherited from her father. Neither the girl (patient) nor her father showed typical features of TSC. This variant is located in a NAGNAG acceptor, which can produce mRNA isoforms that differ by a three-nucleotide indel. Reverse transcription polymerase chain reaction analysis of the patient and both parents' blood RNA samples suggested two different splicing patterns, and these two splicing patterns differed in the presence or absence of the first codon of exon 27, thus providing two splicing products designated as isoforms A and B, respectively. Furthermore, the proportions of these two patterns varied between the patient and either parent. A minigene assay further confirmed that the c.2967-1G>T variant led to the absence of isoform A (including the first codon of exon 27). The finding of our study demonstrates this variant, c.2967-1G>T, disrupts the balance of an alternative splice event which involves the use of two tandem alternatives acceptors and is not associated with typical symptoms of tuberous sclerosis. Our finding is of importance for genetic counseling and suggests that we need to be vigilant to avoid misdiagnosis when we encounter such a site.
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65
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Neuser S, Krey I, Schwan A, Abou Jamra R, Bartolomaeus T, Döring J, Syrbe S, Plassmann M, Rohde S, Roth C, Rehder H, Radtke M, Le Duc D, Schubert S, Bermúdez-Guzmán L, Leal A, Schoner K, Popp B. Prenatal phenotype of PNKP-related primary microcephaly associated with variants affecting both the FHA and phosphatase domain. Eur J Hum Genet 2022; 30:101-110. [PMID: 34697416 PMCID: PMC8738728 DOI: 10.1038/s41431-021-00982-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 09/05/2021] [Accepted: 10/04/2021] [Indexed: 11/20/2022] Open
Abstract
Biallelic PNKP variants cause heterogeneous disorders ranging from neurodevelopmental disorder with microcephaly/seizures to adult-onset Charcot-Marie-Tooth disease. To date, only postnatal descriptions exist. We present the first prenatal diagnosis of PNKP-related primary microcephaly. Pathological examination of a male fetus in the 18th gestational week revealed micrencephaly with extracerebral malformations and thus presumed syndromic microcephaly. A recessive disorder was suspected because of previous pregnancy termination for similar abnormalities. Prenatal trio-exome sequencing identified compound heterozygosity for the PNKP variants c.498G>A, p.[(=),0?] and c.302C>T, p.(Pro101Leu). Segregation confirmed both variants in the sister fetus. Through RNA analyses, we characterized exon 4 skipping affecting the PNKP forkhead-associated (FHA) and phosphatase domains (p.Leu67_Lys166del) as the predominant effect of the paternal c.498G>A variant. We retrospectively investigated two unrelated individuals diagnosed with biallelic PNKP-variants to compare prenatal/postnatal phenotypes. Both carry the splice donor variant c.1029+2T>C in trans with a variant in the FHA domain (c.311T>C, p.(Leu104Pro); c.151G>C, p.(Val51Leu)). RNA-seq showed complex splicing for c.1029+2T>C and c.151G>C. Structural modeling revealed significant clustering of missense variants in the FHA domain with variants generating structural damage. Our clinical description extends the PNKP-continuum to the prenatal stage. Investigating possible PNKP-variant effects using RNA and structural modeling, we highlight the mutational complexity and exemplify a PNKP-variant characterization framework.
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Affiliation(s)
- Sonja Neuser
- Institute of Human Genetics, University of Leipzig Medical Center, Leipzig, Germany.
| | - Ilona Krey
- Institute of Human Genetics, University of Leipzig Medical Center, Leipzig, Germany
| | | | - Rami Abou Jamra
- Institute of Human Genetics, University of Leipzig Medical Center, Leipzig, Germany
| | - Tobias Bartolomaeus
- Institute of Human Genetics, University of Leipzig Medical Center, Leipzig, Germany
| | - Jan Döring
- Department of Pediatrics, Hospital for Children and Adolescents, Heidelberg University Hospital, Heidelberg, Germany
| | - Steffen Syrbe
- Department of Pediatrics, Hospital for Children and Adolescents, Heidelberg University Hospital, Heidelberg, Germany
| | | | - Stefan Rohde
- Department of Radiology and Neuroradiology, Klinikum Dortmund, Dortmund, Germany
| | - Christian Roth
- Department for Pediatric Radiology, University of Leipzig Medical Center, Leipzig, Germany
| | - Helga Rehder
- Institute of Medical Genetics, Medical University Vienna, Vienna, Austria
- Institute of Pathology, Department of Fetal Pathology, Philipps University Marburg, Marburg, Germany
| | - Maximilian Radtke
- Institute of Human Genetics, University of Leipzig Medical Center, Leipzig, Germany
| | - Diana Le Duc
- Institute of Human Genetics, University of Leipzig Medical Center, Leipzig, Germany
| | - Susanna Schubert
- Institute of Human Genetics, University of Leipzig Medical Center, Leipzig, Germany
| | - Luis Bermúdez-Guzmán
- Section of Genetics and Biotechnology, School of Biology, University de Costa Rica, San José, Costa Rica
| | - Alejandro Leal
- Section of Genetics and Biotechnology, School of Biology, University de Costa Rica, San José, Costa Rica
| | - Katharina Schoner
- Institute of Pathology, Department of Fetal Pathology, Philipps University Marburg, Marburg, Germany
| | - Bernt Popp
- Institute of Human Genetics, University of Leipzig Medical Center, Leipzig, Germany.
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66
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Letelier A, Ljung R, Olsson A, Andersson NG. Silent variant in F8:c.222G>T (p.Thr74Thr) causes a partial exon skipping in a patient with mild hemophilia A. Mol Genet Genomic Med 2021; 10:e1856. [PMID: 34962362 PMCID: PMC8801133 DOI: 10.1002/mgg3.1856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Revised: 11/04/2021] [Accepted: 12/14/2021] [Indexed: 11/30/2022] Open
Abstract
One of the challenges of genetic testing in patients with hemophilia A is the interpretation of sequence variants. Here we report a silent variant found in exon 2 in the F8 gene in a 47‐year‐old patient with a previous von Willebrand disease (VWD) type 1 diagnosis. Clinically he had mild bleeding symptoms restricted to prolonged bleeding from minor wounds. Sanger sequencing of F8 gene using genomic DNA showed a hemizygous silent variant in exon 2: c.222G>T, p.Thr74Thr. When applying ACMG criteria, the variant was predicted to be “likely benign” in the analyzing software or VUS after curating. Sanger sequencing of the patient's cDNA after nested polymerase chain reaction showed that the patient had both a normal transcript containing exons 1–4 and a defect transcript lacking exon 2. These findings explain the patient's low FVIII:C level and led to the diagnosis of mild hemophilia A instead of VWD type 1. This case illustrates that mRNA work‐up may be needed to clarify a patient's phenotype–genotype.
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Affiliation(s)
- Anna Letelier
- Department of Clinical Sciences Lund (IKVL)-Pediatrics, Lund University, Lund, Sweden.,Department for Molecular Diagnostics, Clinical Genetics Hemophilia Laboratory, Region Skåne, Skåne University Hospital, Lund, Sweden
| | - Rolf Ljung
- Department of Clinical Sciences Lund (IKVL)-Pediatrics, Lund University, Lund, Sweden
| | - Anna Olsson
- Department of Medicine, Region Västra Götaland, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Nadine G Andersson
- Department of Clinical Sciences Lund (IKVL)-Pediatrics, Lund University, Lund, Sweden.,Department of Pediatric Hematology and Oncology, Region Skåne, Skåne University Hospital, Lund, Sweden
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67
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Sparber P, Mikhaylova S, Galkina V, Itkis Y, Skoblov M. Case Report: Functional Investigation of an Undescribed Missense Variant Affecting Splicing in a Patient With Dravet Syndrome. Front Neurol 2021; 12:761892. [PMID: 34938262 PMCID: PMC8686832 DOI: 10.3389/fneur.2021.761892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 11/02/2021] [Indexed: 11/22/2022] Open
Abstract
Pathogenic variants in the SCN1A gene are associated with a spectrum of epileptic disorders ranging in severity from familial febrile seizures to Dravet syndrome. Large proportions of reported pathogenic variants in SCN1A are annotated as missense variants and are often classified as variants of uncertain significance when no functional data are available. Although loss-of-function variants are associated with a more severe phenotype in SCN1A, the molecular mechanism of single nucleotide variants is often not clear, and genotype-phenotype correlations in SCN1A-related epilepsy remain uncertain. Coding variants can affect splicing by creating novel cryptic splicing sites in exons or by disrupting exonic cis-regulation elements crucial for proper pre-mRNA splicing. Here, we report a novel case of Dravet syndrome caused by an undescribed missense variant, c.4852G>A (p.(Gly1618Ser)). By midigene splicing assay, we demonstrated that the identified variant is in fact splice-affecting. To our knowledge, this is the first report on the functional investigation of a missense variant affecting splicing in Dravet syndrome.
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Affiliation(s)
- Peter Sparber
- Laboratory of Functional Genomics, Research Centre for Medical Genetics, Moscow, Russia
| | - Svetlana Mikhaylova
- Medical Genetics Department, Russian Children's Clinical Hospital, Moscow, Russia
| | - Varvara Galkina
- Clinical Department, Research Centre for Medical Genetics, Moscow, Russia
| | - Yulia Itkis
- Laboratory of Inherited Metabolic Disorders, Research Centre for Medical Genetics, Moscow, Russia
| | - Mikhail Skoblov
- Laboratory of Functional Genomics, Research Centre for Medical Genetics, Moscow, Russia
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68
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Gómez-González C, Pizarro-Sánchez C, Rodríguez-Antolín C, Pascual-Pascual I, Garcia-Romero M, Rodriguez-Jiménez C, de Sancho-Martín R, Del Pozo-Mate Á, Solís-López M, Prior-de Castro C, Torres RJ. Hereditary spastic paraplegia associated with a novel homozygous intronic noncanonical splice site variant in the AP4B1 gene. Ann Hum Genet 2021; 86:109-118. [PMID: 34927723 DOI: 10.1111/ahg.12455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 11/15/2021] [Accepted: 12/02/2021] [Indexed: 11/27/2022]
Abstract
Pathogenic variants in the AP4B1 gene lead to a rare form of hereditary spastic paraplegia (HSP) known as SPG47. We report on a patient with a clinical suspicion of complicated HSP of the lower limbs with intellectual disability, as well as a novel homozygous noncanonical splice site variant in the AP4B1 gene, in which the effect on splicing was validated by RNA analysis. We sequenced 152 genes associated with HSP using Next-Generation Sequencing (NGS). We isolated total RNA from peripheral blood and generated cDNA using reverse transcription-polymerase chain reaction (RT-PCR). A region of AP4B1 mRNA was amplified by PCR and the fragments obtained were purified from the agarose gel and sequenced. We found a homozygous variant of uncertain significance in the AP4B1 gene NM_006594.4: c.1511-6C>G in the proband. Two different AP4B1 mRNA fragments were obtained in the patient and his carrier parents. The shorter fragment was the predominant fragment in the patient and revealed a deletion with skipping of the AP4B1 exon 10. The patient's longer fragment corresponded to an insertion of the last five nucleotides of AP4B1 intron 9. We confirmed that this variant affects the normal splicing of RNA, sustaining the molecular diagnosis of SPG47 in the patient.
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Affiliation(s)
- Clara Gómez-González
- Department of Molecular Genetics, INGEMM, La Paz University Hospital, Madrid, Spain
| | | | - Carlos Rodríguez-Antolín
- Cancer Epigenetics Laboratory, INGEMM, La Paz University Hospital, Madrid, Spain.,Biomarkers and Experimental Therapeutics in Cancer, IdiPAZ, Madrid, Spain
| | | | - Mar Garcia-Romero
- Department of Paediatric Neurology, La Paz University Hospital, Madrid, Spain
| | | | | | | | - Mario Solís-López
- Department of Bioinformatics, INGEMM, La Paz University Hospital, Madrid, Spain
| | | | - Rosa J Torres
- Biochemistry Laboratory, La Paz University Hospital Health Research Institute (FIBHULP), IdiPAZ, Madrid, Spain.,Centre for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Spain
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69
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Bournazos AM, Riley LG, Bommireddipalli S, Ades L, Akesson LS, Al-Shinnag M, Alexander SI, Archibald AD, Balasubramaniam S, Berman Y, Beshay V, Boggs K, Bojadzieva J, Brown NJ, Bryen SJ, Buckley MF, Chong B, Davis MR, Dawes R, Delatycki M, Donaldson L, Downie L, Edwards C, Edwards M, Engel A, Ewans LJ, Faiz F, Fennell A, Field M, Freckmann ML, Gallacher L, Gear R, Goel H, Goh S, Goodwin L, Hanna B, Harraway J, Higgins M, Ho G, Hopper BK, Horton AE, Hunter MF, Huq AJ, Josephi-Taylor S, Joshi H, Kirk E, Krzesinski E, Kumar KR, Lemckert F, Leventer RJ, Lindsey-Temple SE, Lunke S, Ma A, Macaskill S, Mallawaarachchi A, Marty M, Marum JE, McCarthy HJ, Menezes MP, McLean A, Milnes D, Mohammad S, Mowat D, Niaz A, Palmer EE, Patel C, Patel SG, Phelan D, Pinner JR, Rajagopalan S, Regan M, Rodgers J, Rodrigues M, Roxburgh RH, Sachdev R, Roscioli T, Samarasekera R, Sandaradura SA, Savva E, Schindler T, Shah M, Sinnerbrink IB, Smith JM, Smith RJ, Springer A, Stark Z, Strom SP, Sue CM, Tan K, Tan TY, Tantsis E, Tchan MC, Thompson BA, Trainer AH, van Spaendonck-Zwarts K, Walsh R, Warwick L, White S, White SM, Williams MG, Wilson MJ, Wong WK, Wright DC, Yap P, Yeung A, Young H, Jones KJ, Bennetts B, Cooper ST. Standardized practices for RNA diagnostics using clinically accessible specimens reclassifies 75% of putative splicing variants. Genet Med 2021; 24:130-145. [PMID: 34906502 DOI: 10.1016/j.gim.2021.09.001] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 06/18/2021] [Accepted: 09/10/2021] [Indexed: 02/06/2023] Open
Abstract
PURPOSE Genetic variants causing aberrant premessenger RNA splicing are increasingly being recognized as causal variants in genetic disorders. In this study, we devise standardized practices for polymerase chain reaction (PCR)-based RNA diagnostics using clinically accessible specimens (blood, fibroblasts, urothelia, biopsy). METHODS A total of 74 families with diverse monogenic conditions (31% prenatal-congenital onset, 47% early childhood, and 22% teenage-adult onset) were triaged into PCR-based RNA testing, with comparative RNA sequencing for 19 cases. RESULTS Informative RNA assay data were obtained for 96% of cases, enabling variant reclassification for 75% variants that can be used for genetic counseling (71%), to inform clinical care (32%) and prenatal counseling (41%). Variant-associated mis-splicing was highly reproducible for 28 cases with samples from ≥2 affected individuals or heterozygotes and 10 cases with ≥2 biospecimens. PCR amplicons encompassing another segregated heterozygous variant was vital for clinical interpretation of 22 of 79 variants to phase RNA splicing events and discern complete from partial mis-splicing. CONCLUSION RNA diagnostics enabled provision of a genetic diagnosis for 64% of recruited cases. PCR-based RNA diagnostics has capacity to analyze 81.3% of clinically significant genes, with long amplicons providing an advantage over RNA sequencing to phase RNA splicing events. The Australasian Consortium for RNA Diagnostics (SpliceACORD) provide clinically-endorsed, standardized protocols and recommendations for interpreting RNA assay data.
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Affiliation(s)
- Adam M Bournazos
- Kids Neuroscience Centre, Kids Research, The Children's Hospital at Westmead, Westmead, New South Wales, Australia; Department of Child and Adolescent Health, Faculty of Medicine and Health, The University of Sydney, Westmead, New South Wales, Australia
| | - Lisa G Riley
- Department of Child and Adolescent Health, Faculty of Medicine and Health, The University of Sydney, Westmead, New South Wales, Australia; Rare Diseases Functional Genomics, Kids Research, Sydney Children's Hospital Network and Children's Medical Research Institute, Westmead, New South Wales, Australia
| | - Shobhana Bommireddipalli
- Kids Neuroscience Centre, Kids Research, The Children's Hospital at Westmead, Westmead, New South Wales, Australia
| | - Lesley Ades
- Department of Child and Adolescent Health, Faculty of Medicine and Health, The University of Sydney, Westmead, New South Wales, Australia; Department of Clinical Genetics, The Children's Hospital at Westmead, Westmead, New South Wales, Australia
| | - Lauren S Akesson
- Department of Paediatrics, University of Melbourne, Parkville, Victoria, Australia; Department of Medicine, University of Melbourne, Parkville, Victoria, Australia; Department of Pathology, University of Melbourne, Parkville, Victoria, Australia; Department of Genomic Medicine, The Royal Melbourne Hospital, Parkville, Victoria, Australia; Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Parkville, Victoria, Australia; Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia
| | - Mohammad Al-Shinnag
- Genetic Health Queensland, Royal Brisbane and Women's Hospital, Herston, Queensland, Australia; The University of Queensland, Herston, Queensland, Australia
| | - Stephen I Alexander
- Department of Child and Adolescent Health, Faculty of Medicine and Health, The University of Sydney, Westmead, New South Wales, Australia; Department of Pediatric Nephrology, The Children's Hospital at Westmead, Westmead, New South Wales, Australia
| | - Alison D Archibald
- Department of Paediatrics, University of Melbourne, Parkville, Victoria, Australia; Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Parkville, Victoria, Australia
| | - Shanti Balasubramaniam
- Genetic Metabolic Disorders Service, The Children's Hospital at Westmead, Westmead, New South Wales, Australia; Western Sydney Genetics Program, The Children's Hospital at Westmead, Westmead, New South Wales, Australia; Specialty of Genomic Medicine, Faculty of Medicine and Health, The University of Sydney, Westmead, New South Wales, Australia
| | - Yemima Berman
- Department of Clinical Genetics, Royal North Shore Hospital, St Leonards, New South Wales, Australia; Northern Clinical School, Royal North Shore Hospital, St Leonards, New South Wales, Australia
| | - Victoria Beshay
- Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia
| | - Kirsten Boggs
- Department of Clinical Genetics, The Children's Hospital at Westmead, Westmead, New South Wales, Australia; Australian Genomics Health Alliance, Parkville, Victoria, Australia; Centre for Clinical Genetics, Sydney Children's Hospital Randwick, Randwick, New South Wales, Australia
| | - Jasmina Bojadzieva
- Department of Clinical Genetics, Austin Health, Heidelberg, Victoria, Australia
| | - Natasha J Brown
- Department of Paediatrics, University of Melbourne, Parkville, Victoria, Australia; Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Parkville, Victoria, Australia
| | - Samantha J Bryen
- Kids Neuroscience Centre, Kids Research, The Children's Hospital at Westmead, Westmead, New South Wales, Australia; Department of Child and Adolescent Health, Faculty of Medicine and Health, The University of Sydney, Westmead, New South Wales, Australia
| | | | - Belinda Chong
- Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Parkville, Victoria, Australia
| | - Mark R Davis
- Department of Diagnostic Genomics, PathWest Laboratory Medicine, QEII Medical Centre, Nedlands, Western Australia, Australia
| | - Ruebena Dawes
- Kids Neuroscience Centre, Kids Research, The Children's Hospital at Westmead, Westmead, New South Wales, Australia; Department of Child and Adolescent Health, Faculty of Medicine and Health, The University of Sydney, Westmead, New South Wales, Australia
| | - Martin Delatycki
- Department of Paediatrics, University of Melbourne, Parkville, Victoria, Australia; Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Parkville, Victoria, Australia
| | - Liz Donaldson
- The Royal Melbourne Hospital, Parkville, Victoria, Australia
| | - Lilian Downie
- Department of Paediatrics, University of Melbourne, Parkville, Victoria, Australia; The Royal Melbourne Hospital, Parkville, Victoria, Australia; Murdoch Children's Research Institute, Parkville, Victoria, Australia
| | - Caitlin Edwards
- Department of Diagnostic Genomics, PathWest Laboratory Medicine, QEII Medical Centre, Nedlands, Western Australia, Australia
| | - Matthew Edwards
- Department of Paediatrics, School of Medicine, Western Sydney University, Penrith South, New South Wales, Australia
| | - Amanda Engel
- ACT Genetic Service, ACT Health, The Canberra Hospital, Garran, ACT, Australia
| | - Lisa J Ewans
- Department of Medical Genomics, Royal Prince Alfred Hospital, Camperdown, New South Wales, Australia; Central Clinical School, The University of Sydney, Camperdown, New South Wales, Australia
| | - Fathimath Faiz
- Department of Diagnostic Genomics, PathWest Laboratory Medicine, QEII Medical Centre, Nedlands, Western Australia, Australia
| | - Andrew Fennell
- Department of Paediatrics, University of Melbourne, Parkville, Victoria, Australia; Monash Genetics, Monash Health, Clayton, Victoria, Australia
| | - Michael Field
- Genetics of Learning Disability Service, Hunter Genetics, Waratah, New South Wales, Australia
| | | | - Lyndon Gallacher
- Department of Paediatrics, University of Melbourne, Parkville, Victoria, Australia; Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Parkville, Victoria, Australia
| | - Russell Gear
- Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Parkville, Victoria, Australia
| | - Himanshu Goel
- Genetics of Learning Disability Service, Hunter Genetics, Waratah, New South Wales, Australia; The University of Newcastle, Callaghan, New South Wales, Australia
| | - Shuxiang Goh
- Department of Clinical Genetics, Liverpool Hospital, Liverpool, New South Wales, Australia
| | - Linda Goodwin
- Department of Clinical Genetics, Nepean Hospital, Kingswood, New South Wales, Australia
| | - Bernadette Hanna
- Department of Genomic Medicine, Westmead Hospital, Westmead, New South Wales, Australia
| | - James Harraway
- Sullivan Nicolaides Pathology, Bowen Hills, Queensland, Australia
| | - Megan Higgins
- Genetic Health Queensland, Royal Brisbane and Women's Hospital, Herston, Queensland, Australia
| | - Gladys Ho
- Department of Child and Adolescent Health, Faculty of Medicine and Health, The University of Sydney, Westmead, New South Wales, Australia; Department of Molecular Genetics, The Children's Hospital at Westmead, Westmead, New South Wales, Australia
| | | | - Ari E Horton
- Department of Paediatrics, University of Melbourne, Parkville, Victoria, Australia; Monash Genetics, Monash Health, Clayton, Victoria, Australia; Monash Heart and Monash Children's Hospital, Monash Health, Clayton, Victoria, Australia; Monash Cardiovascular Research Centre, Clayton, Victoria, Australia
| | - Matthew F Hunter
- Monash Genetics, Monash Health, Clayton, Victoria, Australia; Department of Paediatrics, Monash University, Clayton, Victoria, Australia
| | - Aamira J Huq
- Department of Medicine, University of Melbourne, Parkville, Victoria, Australia; The Royal Melbourne Hospital, Parkville, Victoria, Australia
| | - Sarah Josephi-Taylor
- Department of Clinical Genetics, The Children's Hospital at Westmead, Westmead, New South Wales, Australia; Department of Genomic Medicine, Westmead Hospital, Westmead, New South Wales, Australia
| | - Himanshu Joshi
- Kids Neuroscience Centre, Kids Research, The Children's Hospital at Westmead, Westmead, New South Wales, Australia
| | - Edwin Kirk
- NSW Health Pathology, Randwick, New South Wales, Australia; Center for Clinical Genetics, Sydney Children's Hospital, Randwick, New South Wales, Australia
| | - Emma Krzesinski
- Monash Genetics, Monash Health, Clayton, Victoria, Australia; Department of Paediatrics, Monash University, Clayton, Victoria, Australia
| | - Kishore R Kumar
- Department of Neurogenetics, Kolling Institute, Faculty of Medicine and Health, University of Sydney, Royal North Shore Hospital, St Leonards, New South Wales, Australia; Translational Genomics, Kinghorn Centre for Clinical Genomics, Garvan Institute for Medical Research, Darlinghurst, New South Wales, Australia
| | - Frances Lemckert
- Kids Neuroscience Centre, Kids Research, The Children's Hospital at Westmead, Westmead, New South Wales, Australia; Department of Child and Adolescent Health, Faculty of Medicine and Health, The University of Sydney, Westmead, New South Wales, Australia
| | - Richard J Leventer
- Department of Paediatrics, University of Melbourne, Parkville, Victoria, Australia; Murdoch Children's Research Institute, Parkville, Victoria, Australia; Department of Neurology, The Royal Children's Hospital, Parkville, Victoria, Australia
| | - Suzanna E Lindsey-Temple
- Department of Clinical Genetics, Liverpool Hospital, Liverpool, New South Wales, Australia; School of Women's and Children's Health, Faculty of Medicine and Health, University of New South Wales, Kensington, NSW, Australia
| | - Sebastian Lunke
- Department of Pathology, University of Melbourne, Parkville, Victoria, Australia; Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Parkville, Victoria, Australia
| | - Alan Ma
- Department of Child and Adolescent Health, Faculty of Medicine and Health, The University of Sydney, Westmead, New South Wales, Australia; Department of Clinical Genetics, The Children's Hospital at Westmead, Westmead, New South Wales, Australia
| | | | - Amali Mallawaarachchi
- Department of Medical Genomics, Royal Prince Alfred Hospital, Camperdown, New South Wales, Australia; Division of Genomics and Epigenetics, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia
| | - Melanie Marty
- Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Parkville, Victoria, Australia
| | - Justine E Marum
- Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Parkville, Victoria, Australia
| | - Hugh J McCarthy
- Department of Child and Adolescent Health, Faculty of Medicine and Health, The University of Sydney, Westmead, New South Wales, Australia; Department of Pediatric Nephrology, The Children's Hospital at Westmead, Westmead, New South Wales, Australia
| | - Manoj P Menezes
- Department of Child and Adolescent Health, Faculty of Medicine and Health, The University of Sydney, Westmead, New South Wales, Australia; The TY Nelson Department of Neurology and Neurosurgery, The Children's Hospital at Westmead, Westmead, New South Wales, Australia
| | - Alison McLean
- Department of Clinical Genetics, Liverpool Hospital, Liverpool, New South Wales, Australia
| | - Di Milnes
- Genetic Health Queensland, Royal Brisbane and Women's Hospital, Herston, Queensland, Australia
| | - Shekeeb Mohammad
- Department of Child and Adolescent Health, Faculty of Medicine and Health, The University of Sydney, Westmead, New South Wales, Australia; The TY Nelson Department of Neurology and Neurosurgery, The Children's Hospital at Westmead, Westmead, New South Wales, Australia
| | - David Mowat
- Center for Clinical Genetics, Sydney Children's Hospital, Randwick, New South Wales, Australia; School of Women's and Children's Health, Faculty of Medicine and Health, University of New South Wales, Kensington, NSW, Australia
| | - Aram Niaz
- Rare Diseases Functional Genomics, Kids Research, Sydney Children's Hospital Network and Children's Medical Research Institute, Westmead, New South Wales, Australia
| | - Elizabeth E Palmer
- Center for Clinical Genetics, Sydney Children's Hospital, Randwick, New South Wales, Australia; School of Women's and Children's Health, Faculty of Medicine and Health, University of New South Wales, Kensington, NSW, Australia
| | - Chirag Patel
- Genetic Health Queensland, Royal Brisbane and Women's Hospital, Herston, Queensland, Australia
| | - Shilpan G Patel
- School of Medicine, The University of Auckland, Auckland, New Zealand
| | - Dean Phelan
- Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Parkville, Victoria, Australia
| | - Jason R Pinner
- Center for Clinical Genetics, Sydney Children's Hospital, Randwick, New South Wales, Australia; School of Women's and Children's Health, Faculty of Medicine and Health, University of New South Wales, Kensington, NSW, Australia
| | - Sulekha Rajagopalan
- Department of Clinical Genetics, Liverpool Hospital, Liverpool, New South Wales, Australia
| | - Matthew Regan
- Monash Genetics, Monash Health, Clayton, Victoria, Australia; Department of Paediatrics, Monash University, Clayton, Victoria, Australia
| | - Jonathan Rodgers
- Genetic Health Queensland, Royal Brisbane and Women's Hospital, Herston, Queensland, Australia
| | - Miriam Rodrigues
- Department of Neurology, Auckland City Hospital, Auckland, New Zealand
| | | | - Rani Sachdev
- Center for Clinical Genetics, Sydney Children's Hospital, Randwick, New South Wales, Australia
| | - Tony Roscioli
- NSW Health Pathology, Randwick, New South Wales, Australia; Center for Clinical Genetics, Sydney Children's Hospital, Randwick, New South Wales, Australia; Neuroscience Research Australia, University of New South Wales, Randwick, New South Wales, Australia
| | - Ruvishani Samarasekera
- Department of Clinical Genetics, The Children's Hospital at Westmead, Westmead, New South Wales, Australia
| | - Sarah A Sandaradura
- Kids Neuroscience Centre, Kids Research, The Children's Hospital at Westmead, Westmead, New South Wales, Australia; Department of Child and Adolescent Health, Faculty of Medicine and Health, The University of Sydney, Westmead, New South Wales, Australia; Department of Clinical Genetics, The Children's Hospital at Westmead, Westmead, New South Wales, Australia
| | - Elena Savva
- Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Parkville, Victoria, Australia
| | - Tim Schindler
- School of Women's and Children's Health, Faculty of Medicine and Health, University of New South Wales, Kensington, NSW, Australia; Newborn Care, Royal Hospital for Women, Randwick, New South Wales, Australia
| | - Margit Shah
- Department of Clinical Genetics, The Children's Hospital at Westmead, Westmead, New South Wales, Australia
| | - Ingrid B Sinnerbrink
- Specialty of Genomic Medicine, Faculty of Medicine and Health, The University of Sydney, Westmead, New South Wales, Australia; Department of Clinical Genetics, Nepean Hospital, Kingswood, New South Wales, Australia
| | - Janine M Smith
- Department of Clinical Genetics, The Children's Hospital at Westmead, Westmead, New South Wales, Australia; Specialty of Genomic Medicine, Faculty of Medicine and Health, The University of Sydney, Westmead, New South Wales, Australia
| | - Richard J Smith
- Molecular Otolaryngology and Renal Research Laboratories, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
| | - Amanda Springer
- Department of Paediatrics, Monash University, Clayton, Victoria, Australia
| | - Zornitza Stark
- Department of Paediatrics, University of Melbourne, Parkville, Victoria, Australia; Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Parkville, Victoria, Australia
| | | | - Carolyn M Sue
- Department of Neurogenetics, Kolling Institute, Faculty of Medicine and Health, University of Sydney, Royal North Shore Hospital, St Leonards, New South Wales, Australia
| | - Kenneth Tan
- Department of Paediatrics, Monash University, Clayton, Victoria, Australia; Monash Newborn, Monash Children's Hospital, Clayton, Victoria, Australia
| | - Tiong Y Tan
- Department of Paediatrics, University of Melbourne, Parkville, Victoria, Australia; Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Parkville, Victoria, Australia
| | - Esther Tantsis
- Department of Child and Adolescent Health, Faculty of Medicine and Health, The University of Sydney, Westmead, New South Wales, Australia; The TY Nelson Department of Neurology and Neurosurgery, The Children's Hospital at Westmead, Westmead, New South Wales, Australia
| | - Michel C Tchan
- Specialty of Genomic Medicine, Faculty of Medicine and Health, The University of Sydney, Westmead, New South Wales, Australia; Department of Genomic Medicine, Westmead Hospital, Westmead, New South Wales, Australia
| | - Bryony A Thompson
- Department of Pathology, The Royal Melbourne Hospital, Parkville, Victoria, Australia; Department of Clinical Pathology, University of Melbourne, Parkville, Victoria, Australia
| | - Alison H Trainer
- Department of Medicine, University of Melbourne, Parkville, Victoria, Australia; Department of Genomic Medicine, The Royal Melbourne Hospital, Parkville, Victoria, Australia
| | | | - Rebecca Walsh
- NSW Health Pathology, Randwick, New South Wales, Australia
| | - Linda Warwick
- ACT Genetic Service, ACT Health, The Canberra Hospital, Garran, ACT, Australia
| | - Stephanie White
- Department of Clinical Genetics, Royal North Shore Hospital, St Leonards, New South Wales, Australia
| | - Susan M White
- Department of Paediatrics, University of Melbourne, Parkville, Victoria, Australia; Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Parkville, Victoria, Australia
| | - Mark G Williams
- Mater Research Institute, The University of Queensland, South Brisbane, Queensland, Australia
| | - Meredith J Wilson
- Department of Clinical Genetics, The Children's Hospital at Westmead, Westmead, New South Wales, Australia; Specialty of Genomic Medicine, Faculty of Medicine and Health, The University of Sydney, Westmead, New South Wales, Australia
| | - Wui Kwan Wong
- Kids Neuroscience Centre, Kids Research, The Children's Hospital at Westmead, Westmead, New South Wales, Australia; Department of Child and Adolescent Health, Faculty of Medicine and Health, The University of Sydney, Westmead, New South Wales, Australia; The TY Nelson Department of Neurology and Neurosurgery, The Children's Hospital at Westmead, Westmead, New South Wales, Australia
| | - Dale C Wright
- Department of Child and Adolescent Health, Faculty of Medicine and Health, The University of Sydney, Westmead, New South Wales, Australia; Specialty of Genomic Medicine, Faculty of Medicine and Health, The University of Sydney, Westmead, New South Wales, Australia; Department of Cytogenetics, The Children's Hospital at Westmead, Westmead, New South Wales, Australia
| | - Patrick Yap
- Northern Hub, Genetic Health Service NZ, Auckland, New Zealand
| | - Alison Yeung
- Department of Paediatrics, University of Melbourne, Parkville, Victoria, Australia; Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Parkville, Victoria, Australia
| | - Helen Young
- Department of Intensive Care, Austin Hospital, Heidelberg, Victoria, Australia
| | - Kristi J Jones
- Kids Neuroscience Centre, Kids Research, The Children's Hospital at Westmead, Westmead, New South Wales, Australia; Department of Child and Adolescent Health, Faculty of Medicine and Health, The University of Sydney, Westmead, New South Wales, Australia; Department of Clinical Genetics, The Children's Hospital at Westmead, Westmead, New South Wales, Australia
| | - Bruce Bennetts
- Department of Child and Adolescent Health, Faculty of Medicine and Health, The University of Sydney, Westmead, New South Wales, Australia; Department of Molecular Genetics, The Children's Hospital at Westmead, Westmead, New South Wales, Australia
| | - Sandra T Cooper
- Kids Neuroscience Centre, Kids Research, The Children's Hospital at Westmead, Westmead, New South Wales, Australia; Department of Child and Adolescent Health, Faculty of Medicine and Health, The University of Sydney, Westmead, New South Wales, Australia; The Children's Medical Research Institute, Westmead, New South Wales, Australia.
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70
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Rowlands C, Thomas HB, Lord J, Wai HA, Arno G, Beaman G, Sergouniotis P, Gomes-Silva B, Campbell C, Gossan N, Hardcastle C, Webb K, O'Callaghan C, Hirst RA, Ramsden S, Jones E, Clayton-Smith J, Webster AR, Douglas AGL, O'Keefe RT, Newman WG, Baralle D, Black GCM, Ellingford JM. Comparison of in silico strategies to prioritize rare genomic variants impacting RNA splicing for the diagnosis of genomic disorders. Sci Rep 2021; 11:20607. [PMID: 34663891 PMCID: PMC8523691 DOI: 10.1038/s41598-021-99747-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 09/13/2021] [Indexed: 12/22/2022] Open
Abstract
The development of computational methods to assess pathogenicity of pre-messenger RNA splicing variants is critical for diagnosis of human disease. We assessed the capability of eight algorithms, and a consensus approach, to prioritize 249 variants of uncertain significance (VUSs) that underwent splicing functional analyses. The capability of algorithms to differentiate VUSs away from the immediate splice site as being 'pathogenic' or 'benign' is likely to have substantial impact on diagnostic testing. We show that SpliceAI is the best single strategy in this regard, but that combined usage of tools using a weighted approach can increase accuracy further. We incorporated prioritization strategies alongside diagnostic testing for rare disorders. We show that 15% of 2783 referred individuals carry rare variants expected to impact splicing that were not initially identified as 'pathogenic' or 'likely pathogenic'; one in five of these cases could lead to new or refined diagnoses.
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Affiliation(s)
- Charlie Rowlands
- North West Genomic Laboratory Hub, Manchester Centre for Genomic Medicine, Manchester University Hospitals NHS Foundation Trust, St Mary's Hospital, Manchester, UK
- Division of Evolution and Genomic Sciences, Neuroscience and Mental Health Domain, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Huw B Thomas
- North West Genomic Laboratory Hub, Manchester Centre for Genomic Medicine, Manchester University Hospitals NHS Foundation Trust, St Mary's Hospital, Manchester, UK
- Division of Evolution and Genomic Sciences, Neuroscience and Mental Health Domain, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Jenny Lord
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Htoo A Wai
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Gavin Arno
- Institute of Ophthalmology, UCL, London, UK
- Moorfields Eye Hospital NHS Foundation Trust, London, UK
- Great Ormond Street Hospital NHS Foundation Trust, London, UK
| | - Glenda Beaman
- North West Genomic Laboratory Hub, Manchester Centre for Genomic Medicine, Manchester University Hospitals NHS Foundation Trust, St Mary's Hospital, Manchester, UK
- Division of Evolution and Genomic Sciences, Neuroscience and Mental Health Domain, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Panagiotis Sergouniotis
- North West Genomic Laboratory Hub, Manchester Centre for Genomic Medicine, Manchester University Hospitals NHS Foundation Trust, St Mary's Hospital, Manchester, UK
- Division of Evolution and Genomic Sciences, Neuroscience and Mental Health Domain, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Beatriz Gomes-Silva
- Division of Evolution and Genomic Sciences, Neuroscience and Mental Health Domain, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Christopher Campbell
- North West Genomic Laboratory Hub, Manchester Centre for Genomic Medicine, Manchester University Hospitals NHS Foundation Trust, St Mary's Hospital, Manchester, UK
| | - Nicole Gossan
- North West Genomic Laboratory Hub, Manchester Centre for Genomic Medicine, Manchester University Hospitals NHS Foundation Trust, St Mary's Hospital, Manchester, UK
| | - Claire Hardcastle
- North West Genomic Laboratory Hub, Manchester Centre for Genomic Medicine, Manchester University Hospitals NHS Foundation Trust, St Mary's Hospital, Manchester, UK
| | - Kevin Webb
- Manchester Adult Cystic Fibrosis Centre, Manchester University Hospitals NHS Foundation Trust, Manchester, UK
| | - Christopher O'Callaghan
- Respiratory, Critical Care and Anaesthesia, UCL Great Ormond Street Institute of Child Health & Great Ormond Street Children's Hospital & NIHR Great Ormond Street Hospital Biomedical Research Centre, London, UK
- Centre for PCD Diagnosis and Research, Department of Infection, Immunity and Inflammation, RKCSB, University of Leicester, Leicester, UK
| | - Robert A Hirst
- Centre for PCD Diagnosis and Research, Department of Infection, Immunity and Inflammation, RKCSB, University of Leicester, Leicester, UK
| | - Simon Ramsden
- North West Genomic Laboratory Hub, Manchester Centre for Genomic Medicine, Manchester University Hospitals NHS Foundation Trust, St Mary's Hospital, Manchester, UK
| | - Elizabeth Jones
- North West Genomic Laboratory Hub, Manchester Centre for Genomic Medicine, Manchester University Hospitals NHS Foundation Trust, St Mary's Hospital, Manchester, UK
| | - Jill Clayton-Smith
- North West Genomic Laboratory Hub, Manchester Centre for Genomic Medicine, Manchester University Hospitals NHS Foundation Trust, St Mary's Hospital, Manchester, UK
- Division of Evolution and Genomic Sciences, Neuroscience and Mental Health Domain, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Andrew R Webster
- Institute of Ophthalmology, UCL, London, UK
- Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Andrew G L Douglas
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, UK
- Wessex Clinical Genetics Service, University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | - Raymond T O'Keefe
- Division of Evolution and Genomic Sciences, Neuroscience and Mental Health Domain, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - William G Newman
- North West Genomic Laboratory Hub, Manchester Centre for Genomic Medicine, Manchester University Hospitals NHS Foundation Trust, St Mary's Hospital, Manchester, UK
- Division of Evolution and Genomic Sciences, Neuroscience and Mental Health Domain, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Diana Baralle
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, UK
- Wessex Clinical Genetics Service, University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | - Graeme C M Black
- North West Genomic Laboratory Hub, Manchester Centre for Genomic Medicine, Manchester University Hospitals NHS Foundation Trust, St Mary's Hospital, Manchester, UK.
- Division of Evolution and Genomic Sciences, Neuroscience and Mental Health Domain, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK.
| | - Jamie M Ellingford
- North West Genomic Laboratory Hub, Manchester Centre for Genomic Medicine, Manchester University Hospitals NHS Foundation Trust, St Mary's Hospital, Manchester, UK.
- Division of Evolution and Genomic Sciences, Neuroscience and Mental Health Domain, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK.
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71
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Olinger E, Al Alawi I, Al Riyami MS, Al Salmi I, Molinari E, Faqeih EA, Al Hamed M, Barroso-Gil M, Powell L, Al-Hussaini AA, Rahim KA, Almontashiri N, Miles C, Shril S, Hildebrandt F, Wilson IJ, Sayer JA. A discarded synonymous variant in NPHP3 explains nephronophthisis and congenital hepatic fibrosis in several families. Hum Mutat 2021; 42:1221-1228. [PMID: 34212438 PMCID: PMC8434971 DOI: 10.1002/humu.24251] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 06/21/2021] [Accepted: 06/28/2021] [Indexed: 02/05/2023]
Abstract
Half of patients with a ciliopathy syndrome remain unsolved after initial analysis of whole exome sequencing (WES) data, highlighting the need for improved variant filtering and annotation. By candidate gene curation of WES data, combined with homozygosity mapping, we detected a homozygous predicted synonymous allele in NPHP3 in two children with hepatorenal fibrocystic disease from a consanguineous family. Analyses on patient-derived RNA shows activation of a cryptic mid-exon splice donor leading to frameshift. Remarkably, the same rare variant was detected in four additional families with hepatorenal disease from UK, US, and Saudi patient cohorts and in addition, another synonymous NPHP3 variant was identified in an unsolved case from the Genomics England 100,000 Genomes data set. We conclude that synonymous NPHP3 variants, not reported before and discarded by pathogenicity pipelines, solved several families with a ciliopathy syndrome. These findings prompt careful reassessment of synonymous variants, especially if they are rare and located in candidate genes.
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Affiliation(s)
- Eric Olinger
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Central Parkway, Newcastle upon Tyne, NE1 3BZ, United Kingdom
| | - Intisar Al Alawi
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Central Parkway, Newcastle upon Tyne, NE1 3BZ, United Kingdom
- National Genetic Center, Ministry of Health, Oman
| | | | - Isa Al Salmi
- National Genetic Center, Ministry of Health, Oman
| | - Elisa Molinari
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Central Parkway, Newcastle upon Tyne, NE1 3BZ, United Kingdom
| | - Eissa Ali Faqeih
- Department of Medical Genetics, Children’s Specialist Hospital, King Fahad Medical City, Riyadh Saudi Arabia
| | - Mohamed Al Hamed
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Miguel Barroso-Gil
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Central Parkway, Newcastle upon Tyne, NE1 3BZ, United Kingdom
| | - Laura Powell
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Central Parkway, Newcastle upon Tyne, NE1 3BZ, United Kingdom
| | - Abdulrahman A. Al-Hussaini
- Department of Medical Genetics, Children’s Specialist Hospital, King Fahad Medical City, Riyadh Saudi Arabia
| | - Khawla A. Rahim
- Department of Medical Genetics, Children’s Specialist Hospital, King Fahad Medical City, Riyadh Saudi Arabia
| | - Naif Almontashiri
- Center for Genetics and Inherited Diseases, Taibah University, Almadinah Almunwarah, Saudi Arabia
| | - Colin Miles
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Central Parkway, Newcastle upon Tyne, NE1 3BZ, United Kingdom
| | - Shirlee Shril
- Division of Nephrology, Department of Pediatrics, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Friedhelm Hildebrandt
- Division of Nephrology, Department of Pediatrics, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
| | | | - Ian J. Wilson
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Central Parkway, Newcastle upon Tyne, NE1 3BZ, United Kingdom
| | - John A. Sayer
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Central Parkway, Newcastle upon Tyne, NE1 3BZ, United Kingdom
- Renal Services, Newcastle Upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, NE7 7DN, United Kingdom
- NIHR Newcastle Biomedical Research Centre, Newcastle upon Tyne, NE4 5PL, United Kingdom
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72
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Wheway G, Thomas NS, Carroll M, Coles J, Doherty R, Goggin P, Green B, Harris A, Hunt D, Jackson CL, Lord J, Mennella V, Thompson J, Walker WT, Lucas JS. Whole genome sequencing in the diagnosis of primary ciliary dyskinesia. BMC Med Genomics 2021; 14:234. [PMID: 34556108 PMCID: PMC8461892 DOI: 10.1186/s12920-021-01084-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 09/14/2021] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND It is estimated that 1-13% of cases of bronchiectasis in adults globally are attributable to primary ciliary dyskinesia (PCD) but many adult patients with bronchiectasis have not been investigated for PCD. PCD is a disorder caused by mutations in genes required for motile cilium structure or function, resulting in impaired mucociliary clearance. Symptoms appear in infancy but diagnosis is often late or missed, often due to the lack of a "gold standard" diagnostic tool and non-specific symptoms. Mutations in > 50 genes account for around 70% of cases, with additional genes, and non-coding, synonymous, missense changes or structural variants (SVs) in known genes presumed to account for the missing heritability. METHODS UK patients with no identified genetic confirmation for the cause of their PCD or bronchiectasis were eligible for whole genome sequencing (WGS) in the Genomics England Ltd 100,000 Genomes Project. 21 PCD probands and 52 non-cystic fibrosis (CF) bronchiectasis probands were recruited in Wessex Genome Medicine Centre (GMC). We carried out analysis of single nucleotide variants (SNVs) and SVs in all families recruited in Wessex GMC. RESULTS 16/21 probands in the PCD cohort received confirmed (n = 9), probable (n = 4) or possible (n = 3) diagnosis from WGS, although 13/16 of these could have been picked up by current standard of care gene panel testing. In the other cases, SVs were identified which were missed by panel testing. We identified variants in novel PCD candidate genes (IFT140 and PLK4) in 2 probands in the PCD cohort. 3/52 probands in the non-CF bronchiectasis cohort received a confirmed (n = 2) or possible (n = 1) diagnosis of PCD. We identified variants in novel PCD candidate genes (CFAP53 and CEP164) in 2 further probands in the non-CF bronchiectasis cohort. CONCLUSIONS Genetic testing is an important component of diagnosing PCD, especially in cases of atypical disease history. WGS is effective in cases where prior gene panel testing has found no variants or only heterozygous variants. In these cases it may detect SVs and is a powerful tool for novel gene discovery.
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Affiliation(s)
- Gabrielle Wheway
- School of Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, UK.
- Institute for Life Sciences, University of Southampton, Southampton, UK.
| | - N Simon Thomas
- School of Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, UK
- Wessex Regional Genetics Laboratory, Salisbury NSF Foundation Trust, Salisbury District Hospital, Salisbury, UK
| | - Mary Carroll
- School of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
- Primary Ciliary Dyskinesia Centre, NIHR Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | - Janice Coles
- School of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
- Primary Ciliary Dyskinesia Centre, NIHR Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | - Regan Doherty
- School of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
- Primary Ciliary Dyskinesia Centre, NIHR Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton, UK
- Biomedical Imaging Unit, University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | - Patricia Goggin
- School of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
- Primary Ciliary Dyskinesia Centre, NIHR Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton, UK
- Biomedical Imaging Unit, University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | - Ben Green
- Queen Alexandra Hospital, Portsmouth Hospitals NHS Trust, Portsmouth, UK
| | - Amanda Harris
- School of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
- Primary Ciliary Dyskinesia Centre, NIHR Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | - David Hunt
- Wessex Clinical Genetics Service, University Hospitals Southampton NHS Foundation Trust, Southampton, UK
| | - Claire L Jackson
- School of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
- Primary Ciliary Dyskinesia Centre, NIHR Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | - Jenny Lord
- School of Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, UK
- Institute for Life Sciences, University of Southampton, Southampton, UK
| | - Vito Mennella
- Institute for Life Sciences, University of Southampton, Southampton, UK
- School of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
- Primary Ciliary Dyskinesia Centre, NIHR Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | - James Thompson
- School of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
- Primary Ciliary Dyskinesia Centre, NIHR Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | - Woolf T Walker
- School of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
- Primary Ciliary Dyskinesia Centre, NIHR Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | - Jane S Lucas
- School of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK.
- Primary Ciliary Dyskinesia Centre, NIHR Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton, UK.
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73
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Ha C, Kim JW, Jang JH. Performance Evaluation of SpliceAI for the Prediction of Splicing of NF1 Variants. Genes (Basel) 2021; 12:1308. [PMID: 34573290 PMCID: PMC8472818 DOI: 10.3390/genes12091308] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 08/21/2021] [Accepted: 08/24/2021] [Indexed: 12/16/2022] Open
Abstract
Neurofibromatosis type 1, characterized by neurofibromas and café-au-lait macules, is one of the most common genetic disorders caused by pathogenic NF1 variants. Because of the high proportion of splicing mutations in NF1, identifying variants that alter splicing may be an essential issue for laboratories. Here, we investigated the sensitivity and specificity of SpliceAI, a recently introduced in silico splicing prediction algorithm in conjunction with other in silico tools. We evaluated 285 NF1 variants identified from 653 patients. The effect on variants on splicing alteration was confirmed by complementary DNA sequencing followed by genomic DNA sequencing. For in silico prediction of splicing effects, we used SpliceAI, MaxEntScan (MES), and Splice Site Finder-like (SSF). The sensitivity and specificity of SpliceAI were 94.5% and 94.3%, respectively, with a cut-off value of Δ Score > 0.22. The area under the curve of SpliceAI was 0.975 (p < 0.0001). Combined analysis of MES/SSF showed a sensitivity of 83.6% and specificity of 82.5%. The concordance rate between SpliceAI and MES/SSF was 84.2%. SpliceAI showed better performance for the prediction of splicing alteration for NF1 variants compared with MES/SSF. As a convenient web-based tool, SpliceAI may be helpful in clinical laboratories conducting DNA-based NF1 sequencing.
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Affiliation(s)
| | | | - Ja-Hyun Jang
- Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro, Gangnam-gu, Seoul 06351, Korea; (C.H.); (J.-W.K.)
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74
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Lin JH, Wu H, Zou WB, Masson E, Fichou Y, Le Gac G, Cooper DN, Férec C, Liao Z, Chen JM. Splicing Outcomes of 5' Splice Site GT>GC Variants That Generate Wild-Type Transcripts Differ Significantly Between Full-Length and Minigene Splicing Assays. Front Genet 2021; 12:701652. [PMID: 34422003 PMCID: PMC8375439 DOI: 10.3389/fgene.2021.701652] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 07/13/2021] [Indexed: 12/18/2022] Open
Abstract
Combining data derived from a meta-analysis of human disease-associated 5' splice site GT>GC (i.e., +2T>C) variants and a cell culture-based full-length gene splicing assay (FLGSA) of forward engineered +2T>C substitutions, we recently estimated that ∼15-18% of +2T>C variants can generate up to 84% wild-type transcripts relative to their wild-type counterparts. Herein, we analyzed the splicing outcomes of 20 +2T>C variants that generate some wild-type transcripts in two minigene assays. We found a high discordance rate in terms of the generation of wild-type transcripts, not only between FLGSA and the minigene assays but also between the different minigene assays. In the pET01 context, all 20 wild-type minigene constructs generated the expected wild-type transcripts; of the 20 corresponding variant minigene constructs, 14 (70%) generated wild-type transcripts. In the pSPL3 context, only 18 of the 20 wild-type minigene constructs generated the expected wild-type transcripts whereas 8 of the 18 (44%) corresponding variant minigene constructs generated wild-type transcripts. Thus, in the context of a particular type of variant, we raise awareness of the limitations of minigene splicing assays and emphasize the importance of sequence context in regulating splicing. Whether or not our findings apply to other types of splice-altering variant remains to be investigated.
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Affiliation(s)
- Jin-Huan Lin
- Department of Gastroenterology, Changhai Hospital, Second Military Medical University, Shanghai, China.,Shanghai Institute of Pancreatic Diseases, Shanghai, China
| | - Hao Wu
- Department of Gastroenterology, Changhai Hospital, Second Military Medical University, Shanghai, China.,Shanghai Institute of Pancreatic Diseases, Shanghai, China
| | - Wen-Bin Zou
- Department of Gastroenterology, Changhai Hospital, Second Military Medical University, Shanghai, China.,Shanghai Institute of Pancreatic Diseases, Shanghai, China
| | - Emmanuelle Masson
- Univ Brest, Inserm, EFS, UMR 1078, GGB, Brest, France.,Service de Génétique Médicale et de Biologie de la Reproduction, CHRU Brest, Brest, France
| | - Yann Fichou
- Univ Brest, Inserm, EFS, UMR 1078, GGB, Brest, France.,Laboratory of Excellence GR-Ex, Paris, France
| | - Gerald Le Gac
- Univ Brest, Inserm, EFS, UMR 1078, GGB, Brest, France.,Service de Génétique Médicale et de Biologie de la Reproduction, CHRU Brest, Brest, France.,Laboratory of Excellence GR-Ex, Paris, France
| | - David N Cooper
- Institute of Medical Genetics, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Claude Férec
- Univ Brest, Inserm, EFS, UMR 1078, GGB, Brest, France.,Service de Génétique Médicale et de Biologie de la Reproduction, CHRU Brest, Brest, France
| | - Zhuan Liao
- Department of Gastroenterology, Changhai Hospital, Second Military Medical University, Shanghai, China.,Shanghai Institute of Pancreatic Diseases, Shanghai, China
| | - Jian-Min Chen
- Univ Brest, Inserm, EFS, UMR 1078, GGB, Brest, France
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Moles-Fernández A, Domènech-Vivó J, Tenés A, Balmaña J, Diez O, Gutiérrez-Enríquez S. Role of Splicing Regulatory Elements and In Silico Tools Usage in the Identification of Deep Intronic Splicing Variants in Hereditary Breast/Ovarian Cancer Genes. Cancers (Basel) 2021; 13:cancers13133341. [PMID: 34283047 PMCID: PMC8268271 DOI: 10.3390/cancers13133341] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 06/25/2021] [Accepted: 06/29/2021] [Indexed: 11/30/2022] Open
Abstract
Simple Summary There is a significant percentage of hereditary breast and ovarian cancer (HBOC) cases that remain undiagnosed, because no pathogenic variant is detected through massively parallel sequencing of coding exons and exon-intron boundaries of high-moderate susceptibility risk genes. Deep intronic regions may contain variants affecting RNA splicing, leading ultimately to disease, and hence they may explain several cases where the genetic cause of HBOC is unknown. This study aims to characterize intronic regions to identify a landscape of “exonizable” zones and test the efficiency of two in silico tools to detect deep intronic variants affecting the mRNA splicing process. Abstract The contribution of deep intronic splice-altering variants to hereditary breast and ovarian cancer (HBOC) is unknown. Current computational in silico tools to predict spliceogenic variants leading to pseudoexons have limited efficiency. We assessed the performance of the SpliceAI tool combined with ESRseq scores to identify spliceogenic deep intronic variants by affecting cryptic sites or splicing regulatory elements (SREs) using literature and experimental datasets. Our results with 233 published deep intronic variants showed that SpliceAI, with a 0.05 threshold, predicts spliceogenic deep intronic variants affecting cryptic splice sites, but is less effective in detecting those affecting SREs. Next, we characterized the SRE profiles using ESRseq, showing that pseudoexons are significantly enriched in SRE-enhancers compared to adjacent intronic regions. Although the combination of SpliceAI with ESRseq scores (considering ∆ESRseq and SRE landscape) showed higher sensitivity, the global performance did not improve because of the higher number of false positives. The combination of both tools was tested in a tumor RNA dataset with 207 intronic variants disrupting splicing, showing a sensitivity of 86%. Following the pipeline, five spliceogenic deep intronic variants were experimentally identified from 33 variants in HBOC genes. Overall, our results provide a framework to detect deep intronic variants disrupting splicing.
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Affiliation(s)
- Alejandro Moles-Fernández
- Hereditary Cancer Genetics Group, Vall d’Hebron Institute of Oncology (VHIO), Vall d’Hebron Barcelona Hospital Campus, 08035 Barcelona, Spain; (A.M.-F.); (J.D.-V.); (J.B.)
| | - Joanna Domènech-Vivó
- Hereditary Cancer Genetics Group, Vall d’Hebron Institute of Oncology (VHIO), Vall d’Hebron Barcelona Hospital Campus, 08035 Barcelona, Spain; (A.M.-F.); (J.D.-V.); (J.B.)
| | - Anna Tenés
- Area of Clinical and Molecular Genetics, Vall d’Hebron Hospital Universitari, Vall d’Hebron Barcelona Hospital Campus, 08035 Barcelona, Spain;
| | - Judith Balmaña
- Hereditary Cancer Genetics Group, Vall d’Hebron Institute of Oncology (VHIO), Vall d’Hebron Barcelona Hospital Campus, 08035 Barcelona, Spain; (A.M.-F.); (J.D.-V.); (J.B.)
- Medical Oncology Department, Vall d’Hebron Hospital Universitari, Vall d’Hebron Barcelona Hospital Campus, 08035 Barcelona, Spain
| | - Orland Diez
- Hereditary Cancer Genetics Group, Vall d’Hebron Institute of Oncology (VHIO), Vall d’Hebron Barcelona Hospital Campus, 08035 Barcelona, Spain; (A.M.-F.); (J.D.-V.); (J.B.)
- Area of Clinical and Molecular Genetics, Vall d’Hebron Hospital Universitari, Vall d’Hebron Barcelona Hospital Campus, 08035 Barcelona, Spain;
- Correspondence: (O.D.); (S.G.-E.)
| | - Sara Gutiérrez-Enríquez
- Hereditary Cancer Genetics Group, Vall d’Hebron Institute of Oncology (VHIO), Vall d’Hebron Barcelona Hospital Campus, 08035 Barcelona, Spain; (A.M.-F.); (J.D.-V.); (J.B.)
- Correspondence: (O.D.); (S.G.-E.)
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76
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Lord J, Baralle D. Splicing in the Diagnosis of Rare Disease: Advances and Challenges. Front Genet 2021; 12:689892. [PMID: 34276790 PMCID: PMC8280750 DOI: 10.3389/fgene.2021.689892] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 06/07/2021] [Indexed: 12/13/2022] Open
Abstract
Mutations which affect splicing are significant contributors to rare disease, but are frequently overlooked by diagnostic sequencing pipelines. Greater ascertainment of pathogenic splicing variants will increase diagnostic yields, ending the diagnostic odyssey for patients and families affected by rare disorders, and improving treatment and care strategies. Advances in sequencing technologies, predictive modeling, and understanding of the mechanisms of splicing in recent years pave the way for improved detection and interpretation of splice affecting variants, yet several limitations still prohibit their routine ascertainment in diagnostic testing. This review explores some of these advances in the context of clinical application and discusses challenges to be overcome before these variants are comprehensively and routinely recognized in diagnostics.
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Affiliation(s)
- Jenny Lord
- School of Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Diana Baralle
- School of Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
- Wessex Clinical Genetics Service, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom
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77
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Riepe TV, Khan M, Roosing S, Cremers FPM, 't Hoen PAC. Benchmarking deep learning splice prediction tools using functional splice assays. Hum Mutat 2021; 42:799-810. [PMID: 33942434 PMCID: PMC8360004 DOI: 10.1002/humu.24212] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 03/16/2021] [Accepted: 04/17/2021] [Indexed: 12/21/2022]
Abstract
Hereditary disorders are frequently caused by genetic variants that affect pre-messenger RNA splicing. Though genetic variants in the canonical splice motifs are almost always disrupting splicing, the pathogenicity of variants in the noncanonical splice sites (NCSS) and deep intronic (DI) regions are difficult to predict. Multiple splice prediction tools have been developed for this purpose, with the latest tools employing deep learning algorithms. We benchmarked established and deep learning splice prediction tools on published gold standard sets of 71 NCSS and 81 DI variants in the ABCA4 gene and 61 NCSS variants in the MYBPC3 gene with functional assessment in midigene and minigene splice assays. The selection of splice prediction tools included CADD, DSSP, GeneSplicer, MaxEntScan, MMSplice, NNSPLICE, SPIDEX, SpliceAI, SpliceRover, and SpliceSiteFinder-like. The best-performing splice prediction tool for the different variants was SpliceRover for ABCA4 NCSS variants, SpliceAI for ABCA4 DI variants, and the Alamut 3/4 consensus approach (GeneSplicer, MaxEntScacn, NNSPLICE and SpliceSiteFinder-like) for NCSS variants in MYBPC3 based on the area under the receiver operator curve. Overall, the performance in a real-time clinical setting is much more modest than reported by the developers of the tools.
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Affiliation(s)
- Tabea V. Riepe
- Centre for Molecular and Biomolecular Informatics, Radboud Institute for Molecular Life SciencesRadboud University Medical CenterNijmegenThe Netherlands
- Department of Human Genetics and Donders Institute for Brain, Cognition and BehaviorRadboud University Medical CenterNijmegenThe Netherlands
| | - Mubeen Khan
- Department of Human Genetics and Donders Institute for Brain, Cognition and BehaviorRadboud University Medical CenterNijmegenThe Netherlands
| | - Susanne Roosing
- Department of Human Genetics and Donders Institute for Brain, Cognition and BehaviorRadboud University Medical CenterNijmegenThe Netherlands
| | - Frans P. M. Cremers
- Department of Human Genetics and Donders Institute for Brain, Cognition and BehaviorRadboud University Medical CenterNijmegenThe Netherlands
| | - Peter A. C. 't Hoen
- Centre for Molecular and Biomolecular Informatics, Radboud Institute for Molecular Life SciencesRadboud University Medical CenterNijmegenThe Netherlands
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78
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Seaby EG, Rehm HL, O’Donnell-Luria A. Strategies to Uplift Novel Mendelian Gene Discovery for Improved Clinical Outcomes. Front Genet 2021; 12:674295. [PMID: 34220947 PMCID: PMC8248347 DOI: 10.3389/fgene.2021.674295] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 05/12/2021] [Indexed: 01/31/2023] Open
Abstract
Rare genetic disorders, while individually rare, are collectively common. They represent some of the most severe disorders affecting patients worldwide with significant morbidity and mortality. Over the last decade, advances in genomic methods have significantly uplifted diagnostic rates for patients and facilitated novel and targeted therapies. However, many patients with rare genetic disorders still remain undiagnosed as the genetic etiology of only a proportion of Mendelian conditions has been discovered to date. This article explores existing strategies to identify novel Mendelian genes and how these discoveries impact clinical care and therapeutics. We discuss the importance of data sharing, phenotype-driven approaches, patient-led approaches, utilization of large-scale genomic sequencing projects, constraint-based methods, integration of multi-omics data, and gene-to-patient methods. We further consider the health economic advantages of novel gene discovery and speculate on potential future methods for improved clinical outcomes.
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Affiliation(s)
- Eleanor G. Seaby
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, United States
- Genomic Informatics Group, University Hospital Southampton, Southampton, United Kingdom
- Center for Genomic Medicine, Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, MA, United States
- Division of Genetics and Genomics, Boston Children’s Hospital, Boston, MA, United States
| | - Heidi L. Rehm
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, United States
- Center for Genomic Medicine, Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, MA, United States
| | - Anne O’Donnell-Luria
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, United States
- Center for Genomic Medicine, Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, MA, United States
- Division of Genetics and Genomics, Boston Children’s Hospital, Boston, MA, United States
- Manton Center for Orphan Disease Research, Boston Children’s Hospital, Boston, MA, United States
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79
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Li Q, Wang Y, Pan Y, Wang J, Yu W, Wang X. Unraveling synonymous and deep intronic variants causing aberrant splicing in two genetically undiagnosed epilepsy families. BMC Med Genomics 2021; 14:152. [PMID: 34107977 PMCID: PMC8188693 DOI: 10.1186/s12920-021-01008-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 06/04/2021] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Variants identified through parent-child trio-WES yield up to 28-55% positive diagnostic rate across a variety of Mendelian disorders, there remain numerous patients who do not receive a genetic diagnosis. Studies showed that some aberrant splicing variants, which are either not readily detectable by WES or could be miss-interpreted by regular detecting pipelines, are highly relevant to human diseases. METHODS We retrospectively investigated the negative molecular diagnostics through trio-WES for 15 genetically undiagnosed patients whose clinical manifestations were highly suspected to be genetic disorders with well-established genotype-phenotype relationships. We scrutinized the synonymous variants from WES data and Sanger sequenced the suspected intronic region for deep intronic variants. The functional consequences of variants were analyzed by in vitro minigene experiments. RESULTS Here, we report two abnormal splicing events, one of which caused exon truncating due to the activation of cryptic splicing site by a synonymous variant; the other caused partial intron retention due to the generation of splicing sites by a deep intronic variant. CONCLUSIONS We suggest that, despite initial negative genetic test results in clinically highly suspected genetic diseases, the combination of predictive bioinformatics and functional analysis should be considered to unveil the genetic etiology of undiagnosed rare diseases.
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Affiliation(s)
- Qiang Li
- Guiyang Maternal and Child Health Care Hospital, Guiyang, 550002, China.
| | | | - Yijun Pan
- Guiyang Maternal and Child Health Care Hospital, Guiyang, 550002, China
| | - Jia Wang
- Cipher Gene, Ltd., Beijing, 100080, China
| | - Weishi Yu
- Cipher Gene, Ltd., Beijing, 100080, China
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80
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Apetrei A, Molin A, Gruchy N, Godin M, Bracquemart C, Resbeut A, Rey G, Nadeau G, Richard N. A novel synonymous variant in exon 1 of GNAS gene results in a cryptic splice site and causes pseudohypoparathyroidism type 1A and pseudo-pseudohypoparathyroidism in a French family. Bone Rep 2021; 14:101073. [PMID: 33997150 PMCID: PMC8100090 DOI: 10.1016/j.bonr.2021.101073] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 04/17/2021] [Accepted: 04/20/2021] [Indexed: 12/31/2022] Open
Abstract
INTRODUCTION Pseudohypoparathyroidism type 1A (PHP1A) and pseudopseudohypoparathyroidism (PPHP) (Inactivating PTH/PTHrP Signaling Disorders type 2, IPPSD2) are two rare autosomal disorders caused by loss-of-function mutations on either maternal or paternal allele, respectively, in the imprinted GNAS gene, which encodes the α subunit of the ubiquitously-expressed stimulatory G protein (Gαs). CASE PRESENTATION We investigated a synonymous GNAS variant NM_001077488.2: c.108C>A / p.(Val36=) identified in a family presenting with IPPSD2 phenotype. In silico splicing prediction algorithms were in favor of a deleterious effect of this variant, by creating a new donor splicing site. The GNAS expression studies in blood suggested haploinsufficiency and showed an alternate splice product demonstrating the unmasking of a cryptic site, leading to a 34 base pairs deletion and the creation of a probable unstable RNA.We present the first familial case of IPPSD2 caused by a pathogenic synonymous variant in GNAS gene.
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Affiliation(s)
- Andreea Apetrei
- Normandy University, UNICAEN, Caen University Hospital, Department of Genetics, Reference Center of Rare Diseases of Calcium and Phosphorus Metabolism, EA 7450 BioTARGen, Caen, France
| | - Arnaud Molin
- Normandy University, UNICAEN, Caen University Hospital, Department of Genetics, Reference Center of Rare Diseases of Calcium and Phosphorus Metabolism, EA 7450 BioTARGen, Caen, France
| | - Nicolas Gruchy
- Normandy University, UNICAEN, Caen University Hospital, Department of Genetics, Reference Center of Rare Diseases of Calcium and Phosphorus Metabolism, EA 7450 BioTARGen, Caen, France
| | - Manon Godin
- Normandy University, UNICAEN, Caen University Hospital, Department of Genetics, Reference Center of Rare Diseases of Calcium and Phosphorus Metabolism, EA 7450 BioTARGen, Caen, France
| | - Claire Bracquemart
- Normandy University, UNICAEN, Caen University Hospital, Department of Genetics, Reference Center of Rare Diseases of Calcium and Phosphorus Metabolism, EA 7450 BioTARGen, Caen, France
| | - Antoine Resbeut
- Normandy University, UNICAEN, Caen University Hospital, Department of Genetics, Reference Center of Rare Diseases of Calcium and Phosphorus Metabolism, EA 7450 BioTARGen, Caen, France
| | - Gaëlle Rey
- Metropole Savoie Hospital Center, Genetics Department, Chambéry, France
| | - Gwenaël Nadeau
- Metropole Savoie Hospital Center, Genetics Department, Chambéry, France
| | - Nicolas Richard
- Normandy University, UNICAEN, Caen University Hospital, Department of Genetics, Reference Center of Rare Diseases of Calcium and Phosphorus Metabolism, EA 7450 BioTARGen, Caen, France
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81
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Agiannitopoulos K, Pepe G, Papadopoulou E, Tsaousis GN, Kampouri S, Maravelaki S, Fassas A, Christodoulou C, Iosifidou R, Karageorgopoulou S, Markopoulos C, Natsiopoulos I, Papazisis K, Vasilaki-Antonatou M, Venizelos V, Ozmen V, Tansan S, Kaban K, Eniu DT, Chiorean A, Nasioulas G. Clinical Utility of Functional RNA Analysis for the Reclassification of Splicing Gene Variants in Hereditary Cancer. Cancer Genomics Proteomics 2021; 18:285-294. [PMID: 33893081 DOI: 10.21873/cgp.20259] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 03/24/2021] [Accepted: 03/29/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Classification of splicing variants (SVs) in genes associated with hereditary cancer is often challenging. The aim of this study was to investigate the occurrence of SVs in hereditary cancer genes and the clinical utility of RNA analysis. MATERIAL AND METHODS 1518 individuals were tested for cancer predisposition, using a Next Generation Sequencing (NGS) panel of 36 genes. Splicing variant analysis was performed using RT-PCR and Sanger Sequencing. RESULTS In total, 34 different SVs were identified, 53% of which were classified as pathogenic or likely pathogenic. The remaining 16 variants were initially classified as Variant of Uncertain Significance (VUS). RNA analysis was performed for 3 novel variants. CONCLUSION The RNA analysis assisted in the reclassification of 20% of splicing variants from VUS to pathogenic. RNA analysis is essential in the case of uncharacterized splicing variants, for proper classification and personalized management of these patients.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Vahit Ozmen
- Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | | | | | - Dan Tudor Eniu
- Institutul Oncologic Prof. Dr. I. Chiricuta, Cluj, Romania
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Truty R, Ouyang K, Rojahn S, Garcia S, Colavin A, Hamlington B, Freivogel M, Nussbaum RL, Nykamp K, Aradhya S. Spectrum of splicing variants in disease genes and the ability of RNA analysis to reduce uncertainty in clinical interpretation. Am J Hum Genet 2021; 108:696-708. [PMID: 33743207 PMCID: PMC8059334 DOI: 10.1016/j.ajhg.2021.03.006] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 03/02/2021] [Indexed: 12/20/2022] Open
Abstract
The complexities of gene expression pose challenges for the clinical interpretation of splicing variants. To better understand splicing variants and their contribution to hereditary disease, we evaluated their prevalence, clinical classifications, and associations with diseases, inheritance, and functional characteristics in a 689,321-person clinical cohort and two large public datasets. In the clinical cohort, splicing variants represented 13% of all variants classified as pathogenic (P), likely pathogenic (LP), or variants of uncertain significance (VUSs). Most splicing variants were outside essential splice sites and were classified as VUSs. Among all individuals tested, 5.4% had a splicing VUS. If RNA analysis were to contribute supporting evidence to variant interpretation, we estimated that splicing VUSs would be reclassified in 1.7% of individuals in our cohort. This would result in a clinically significant result (i.e., P/LP) in 0.1% of individuals overall because most reclassifications would change VUSs to likely benign. In ClinVar, splicing VUSs were 4.8% of reported variants and could benefit from RNA analysis. In the Genome Aggregation Database (gnomAD), splicing variants comprised 9.4% of variants in protein-coding genes; most were rare, precluding unambiguous classification as benign. Splicing variants were depleted in genes associated with dominant inheritance and haploinsufficiency, although some genes had rare variants at essential splice sites or had common splicing variants that were most likely compatible with normal gene function. Overall, we describe the contribution of splicing variants to hereditary disease, the potential utility of RNA analysis for reclassifying splicing VUSs, and how natural variation may confound clinical interpretation of splicing variants.
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Affiliation(s)
| | - Karen Ouyang
- Invitae, 1400 16th St, San Francisco, CA 94103, USA
| | - Susan Rojahn
- Invitae, 1400 16th St, San Francisco, CA 94103, USA
| | - Sarah Garcia
- Invitae, 1400 16th St, San Francisco, CA 94103, USA
| | | | | | | | | | - Keith Nykamp
- Invitae, 1400 16th St, San Francisco, CA 94103, USA
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83
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Macken WL, Vandrovcova J, Hanna MG, Pitceathly RDS. Applying genomic and transcriptomic advances to mitochondrial medicine. Nat Rev Neurol 2021; 17:215-230. [PMID: 33623159 DOI: 10.1038/s41582-021-00455-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/06/2021] [Indexed: 02/07/2023]
Abstract
Next-generation sequencing (NGS) has increased our understanding of the molecular basis of many primary mitochondrial diseases (PMDs). Despite this progress, many patients with suspected PMD remain without a genetic diagnosis, which restricts their access to in-depth genetic counselling, reproductive options and clinical trials, in addition to hampering efforts to understand the underlying disease mechanisms. Although they represent a considerable improvement over their predecessors, current methods for sequencing the mitochondrial and nuclear genomes have important limitations, and molecular diagnostic techniques are often manual and time consuming. However, recent advances in genomics and transcriptomics offer realistic solutions to these challenges. In this Review, we discuss the current genetic testing approach for PMDs and the opportunities that exist for increased use of whole-genome NGS of nuclear and mitochondrial DNA (mtDNA) in the clinical environment. We consider the possible role for long-read approaches in sequencing of mtDNA and in the identification of novel nuclear genomic causes of PMDs. We examine the expanding applications of RNA sequencing, including the detection of cryptic variants that affect splicing and gene expression and the interpretation of rare and novel mitochondrial transfer RNA variants.
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Affiliation(s)
- William L Macken
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK
| | - Jana Vandrovcova
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK
| | - Michael G Hanna
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK
| | - Robert D S Pitceathly
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK.
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84
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Qian X, Wang J, Wang M, Igelman AD, Jones KD, Li Y, Wang K, Goetz KE, Birch DG, Yang P, Pennesi ME, Chen R. Identification of Deep-Intronic Splice Mutations in a Large Cohort of Patients With Inherited Retinal Diseases. Front Genet 2021; 12:647400. [PMID: 33737949 PMCID: PMC7960924 DOI: 10.3389/fgene.2021.647400] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 02/11/2021] [Indexed: 12/13/2022] Open
Abstract
High throughput sequencing technologies have revolutionized the identification of mutations responsible for a diverse set of Mendelian disorders, including inherited retinal disorders (IRDs). However, the causal mutations remain elusive for a significant proportion of patients. This may be partially due to pathogenic mutations located in non-coding regions, which are largely missed by capture sequencing targeting the coding regions. The advent of whole-genome sequencing (WGS) allows us to systematically detect non-coding variations. However, the interpretation of these variations remains a significant bottleneck. In this study, we investigated the contribution of deep-intronic splice variants to IRDs. WGS was performed for a cohort of 571 IRD patients who lack a confident molecular diagnosis, and potential deep intronic variants that affect proper splicing were identified using SpliceAI. A total of six deleterious deep intronic variants were identified in eight patients. An in vitro minigene system was applied to further validate the effect of these variants on the splicing pattern of the associated genes. The prediction scores assigned to splice-site disruption positively correlated with the impact of mutations on splicing, as those with lower prediction scores demonstrated partial splicing. Through this study, we estimated the contribution of deep-intronic splice mutations to unassigned IRD patients and leveraged in silico and in vitro methods to establish a framework for prioritizing deep intronic variant candidates for mechanistic and functional analyses.
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Affiliation(s)
- Xinye Qian
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, United States.,Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, United States
| | - Jun Wang
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, United States.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Meng Wang
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, United States.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Austin D Igelman
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, OR, United States
| | - Kaylie D Jones
- Retina Foundation of the Southwest and Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Yumei Li
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, United States
| | - Keqing Wang
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, United States
| | - Kerry E Goetz
- Office of the Director, National Eye Institute/National Institutes of Health, Bethesda, MD, United States
| | - David G Birch
- Retina Foundation of the Southwest and Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Paul Yang
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, OR, United States
| | - Mark E Pennesi
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, OR, United States
| | - Rui Chen
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX, United States.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
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85
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Saint-Martin C, Cauchois-Le Mière M, Rex E, Soukarieh O, Arnoux JB, Buratti J, Bouvet D, Frébourg T, Gaildrat P, Shyng SL, Bellanné-Chantelot C, Martins A. Functional characterization of ABCC8 variants of unknown significance based on bioinformatics predictions, splicing assays, and protein analyses: Benefits for the accurate diagnosis of congenital hyperinsulinism. Hum Mutat 2021; 42:408-420. [PMID: 33410562 DOI: 10.1002/humu.24164] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 12/06/2020] [Accepted: 12/31/2020] [Indexed: 12/20/2022]
Abstract
ABCC8 encodes the SUR1 subunit of the β-cell ATP-sensitive potassium channel whose loss of function causes congenital hyperinsulinism (CHI). Molecular diagnosis is critical for optimal management of CHI patients. Unfortunately, assessing the impact of ABCC8 variants on RNA splicing remains very challenging as this gene is poorly expressed in leukocytes. Here, we performed bioinformatics analysis and cell-based minigene assays to assess the impact on splicing of 13 ABCC8 variants identified in 20 CHI patients. Next, channel properties of SUR1 proteins expected to originate from minigene-detected in-frame splicing defects were analyzed after ectopic expression in COSm6 cells. Out of the analyzed variants, seven induced out-of-frame splicing defects and were therefore classified as recessive pathogenic, whereas two led to skipping of in-frame exons. Channel functional analysis of the latter demonstrated their pathogenicity. Interestingly, the common rs757110 SNP increased exon skipping in our system suggesting that it may act as a disease modifier factor. Our strategy allowed determining the pathogenicity of all selected ABCC8 variants, and CHI-inheritance pattern for 16 out of the 20 patients. This study highlights the value of combining RNA and protein functional approaches in variant interpretation and reveals the minigene splicing assay as a new tool for CHI molecular diagnostics.
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Affiliation(s)
- Cécile Saint-Martin
- Department of Genetics, AP-HP Pitié-Salpêtrière Hospital, Sorbonne University, Paris, France
| | - Marine Cauchois-Le Mière
- Inserm U1245, UFR de Médecine et Pharmacie, UNIROUEN, Normandie University, Normandy Centre for Genomic and Personalized Medicine, Rouen, France.,Department of Genetics, University Hospital, Normandy Centre for Genomic and Personalized Medicine, Rouen, France
| | - Emily Rex
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR, USA
| | - Omar Soukarieh
- Inserm U1245, UFR de Médecine et Pharmacie, UNIROUEN, Normandie University, Normandy Centre for Genomic and Personalized Medicine, Rouen, France
| | - Jean-Baptiste Arnoux
- Department of Inherited Metabolic Disease, Necker-Enfants Malades University Hospital, AP-HP, Paris, France
| | - Julien Buratti
- Department of Genetics, AP-HP Pitié-Salpêtrière Hospital, Sorbonne University, Paris, France
| | - Delphine Bouvet
- Department of Genetics, AP-HP Pitié-Salpêtrière Hospital, Sorbonne University, Paris, France
| | - Thierry Frébourg
- Inserm U1245, UFR de Médecine et Pharmacie, UNIROUEN, Normandie University, Normandy Centre for Genomic and Personalized Medicine, Rouen, France.,Department of Genetics, University Hospital, Normandy Centre for Genomic and Personalized Medicine, Rouen, France
| | - Pascaline Gaildrat
- Inserm U1245, UFR de Médecine et Pharmacie, UNIROUEN, Normandie University, Normandy Centre for Genomic and Personalized Medicine, Rouen, France
| | - Show-Ling Shyng
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR, USA
| | | | - Alexandra Martins
- Inserm U1245, UFR de Médecine et Pharmacie, UNIROUEN, Normandie University, Normandy Centre for Genomic and Personalized Medicine, Rouen, France
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86
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Murdock DR, Dai H, Burrage LC, Rosenfeld JA, Ketkar S, Müller MF, Yépez VA, Gagneur J, Liu P, Chen S, Jain M, Zapata G, Bacino CA, Chao HT, Moretti P, Craigen WJ, Hanchard NA, Lee B. Transcriptome-directed analysis for Mendelian disease diagnosis overcomes limitations of conventional genomic testing. J Clin Invest 2021; 131:141500. [PMID: 33001864 PMCID: PMC7773386 DOI: 10.1172/jci141500] [Citation(s) in RCA: 81] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 09/24/2020] [Indexed: 12/28/2022] Open
Abstract
BACKGROUNDTranscriptome sequencing (RNA-seq) improves diagnostic rates in individuals with suspected Mendelian conditions to varying degrees, primarily by directing the prioritization of candidate DNA variants identified on exome or genome sequencing (ES/GS). Here we implemented an RNA-seq-guided method to diagnose individuals across a wide range of ages and clinical phenotypes.METHODSOne hundred fifteen undiagnosed adult and pediatric patients with diverse phenotypes and 67 family members (182 total individuals) underwent RNA-seq from whole blood and skin fibroblasts at the Baylor College of Medicine (BCM) Undiagnosed Diseases Network clinical site from 2014 to 2020. We implemented a workflow to detect outliers in gene expression and splicing for cases that remained undiagnosed despite standard genomic and transcriptomic analysis.RESULTSThe transcriptome-directed approach resulted in a diagnostic rate of 12% across the entire cohort, or 17% after excluding cases solved on ES/GS alone. Newly diagnosed conditions included Koolen-de Vries syndrome (KANSL1), Renpenning syndrome (PQBP1), TBCK-associated encephalopathy, NSD2- and CLTC-related intellectual disability, and others, all with negative conventional genomic testing, including ES and chromosomal microarray (CMA). Skin fibroblasts exhibited higher and more consistent expression of clinically relevant genes than whole blood. In solved cases with RNA-seq from both tissues, the causative defect was missed in blood in half the cases but none from fibroblasts.CONCLUSIONSFor our cohort of undiagnosed individuals with suspected Mendelian conditions, transcriptome-directed genomic analysis facilitated diagnoses, primarily through the identification of variants missed on ES and CMA.TRIAL REGISTRATIONNot applicable.FUNDINGNIH Common Fund, BCM Intellectual and Developmental Disabilities Research Center, Eunice Kennedy Shriver National Institute of Child Health & Human Development.
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Affiliation(s)
- David R. Murdock
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, Texas, USA
| | - Hongzheng Dai
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, Texas, USA
- Baylor Genetics, Houston, Texas, USA
| | - Lindsay C. Burrage
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, Texas, USA
- Texas Children’s Hospital, Houston, Texas, USA
| | - Jill A. Rosenfeld
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, Texas, USA
| | - Shamika Ketkar
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, Texas, USA
| | - Michaela F. Müller
- Department of Informatics, Technical University of Munich, Garching, Germany
| | - Vicente A. Yépez
- Department of Informatics, Technical University of Munich, Garching, Germany
| | - Julien Gagneur
- Department of Informatics, Technical University of Munich, Garching, Germany
| | - Pengfei Liu
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, Texas, USA
- Baylor Genetics, Houston, Texas, USA
| | - Shan Chen
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, Texas, USA
| | - Mahim Jain
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, Texas, USA
| | - Gladys Zapata
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, Texas, USA
- Laboratory for Translational Genomics, Agricultural Research Service (ARS)/United States Department of Agriculture (USDA) Children’s Nutrition Research Center, and
| | - Carlos A. Bacino
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, Texas, USA
- Texas Children’s Hospital, Houston, Texas, USA
| | - Hsiao-Tuan Chao
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, Texas, USA
- Texas Children’s Hospital, Houston, Texas, USA
- Departments of Neuroscience and Pediatrics, Division of Neurology and Developmental Neuroscience, BCM, Houston, Texas, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, Texas, USA
- McNair Medical Institute at the Robert and Janice McNair Foundation, Houston, Texas, USA
| | - Paolo Moretti
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, Texas, USA
- Department of Neurology, University of Utah and George E. Wahlen Department of Veterans Affairs Medical Center, Salt Lake City, Utah, USA
| | - William J. Craigen
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, Texas, USA
- Texas Children’s Hospital, Houston, Texas, USA
| | - Neil A. Hanchard
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, Texas, USA
- Texas Children’s Hospital, Houston, Texas, USA
- Laboratory for Translational Genomics, Agricultural Research Service (ARS)/United States Department of Agriculture (USDA) Children’s Nutrition Research Center, and
| | | | - Brendan Lee
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, Texas, USA
- Texas Children’s Hospital, Houston, Texas, USA
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87
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When phenotype does not match genotype: importance of "real-time" refining of phenotypic information for exome data interpretation. Genet Med 2020; 23:215-221. [PMID: 32801363 DOI: 10.1038/s41436-020-00938-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 07/31/2020] [Accepted: 07/31/2020] [Indexed: 02/03/2023] Open
Abstract
PURPOSE Clinical data provided to genetic testing laboratories are frequently scarce. Our purpose was to evaluate clinical scenarios where phenotypic refinement in proband's family members might impact exome data interpretation. METHODS Of 614 exomes, 209 were diagnostic and included in this study. Phenotypic information was gathered by the variant interpretation team from genetic counseling letters and images. If a discrepancy between reported clinical findings and presumably disease-causing variant segregation was observed, referring clinicians were contacted for phenotypic clarification. RESULTS In 16/209 (7.7%) cases, phenotypic refinement was important due to (1) lack of cosegregation of disease-causing variant with the reported phenotype; (2) identification of different disorders with overlapping symptoms in the same family; (3) similar features in proband and family members, but molecular cause identified in proband only; and (4) previously unrecognized maternal condition causative of child's phenotype. As a result of phenotypic clarification, in 12/16 (75%) cases definition of affected versus unaffected status in one of the family members has changed, and in one case variant classification has changed. CONCLUSION Detailed description of phenotypes in family members including differences in clinical presentations, even if subtle, are important in exome interpretation and should be communicated to the variant interpretation team.
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88
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Di Scipio M, Tavares E, Deshmukh S, Audo I, Green-Sanderson K, Zubak Y, Zine-Eddine F, Pearson A, Vig A, Tang CY, Mollica A, Karas J, Tumber A, Yu CW, Billingsley G, Wilson MD, Zeitz C, Héon E, Vincent A. Phenotype Driven Analysis of Whole Genome Sequencing Identifies Deep Intronic Variants that Cause Retinal Dystrophies by Aberrant Exonization. Invest Ophthalmol Vis Sci 2020; 61:36. [PMID: 32881472 PMCID: PMC7443117 DOI: 10.1167/iovs.61.10.36] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 07/16/2020] [Indexed: 02/07/2023] Open
Abstract
Purpose To demonstrate the effectiveness of combining retinal phenotyping and focused variant filtering from genome sequencing (GS) in identifying deep intronic disease causing variants in inherited retinal dystrophies. Methods Affected members from three pedigrees with classical enhanced S-cone syndrome (ESCS; Pedigree 1), congenital stationary night blindness (CSNB; Pedigree 2), and achromatopsia (ACHM; Pedigree 3), respectively, underwent detailed ophthalmologic evaluation, optical coherence tomography, and electroretinography. The probands underwent panel-based genetic testing followed by GS analysis. Minigene constructs (NR2E3, GPR179 and CNGB3) and patient-derived cDNA experiments (NR2E3 and GPR179) were performed to assess the functional effect of the deep intronic variants. Results The electrophysiological findings confirmed the clinical diagnosis of ESCS, CSNB, and ACHM in the respective pedigrees. Panel-based testing revealed heterozygous pathogenic variants in NR2E3 (NM_014249.3; c.119-2A>C; Pedigree 1) and CNGB3 (NM_019098.4; c.1148delC/p.Thr383Ilefs*13; Pedigree 3). The GS revealed heterozygous deep intronic variants in Pedigrees 1 (NR2E3; c.1100+1124G>A) and 3 (CNGB3; c.852+4751A>T), and a homozygous GPR179 variant in Pedigree 2 (NM_001004334.3; c.903+343G>A). The identified variants segregated with the phenotype in all pedigrees. All deep intronic variants were predicted to generate a splice acceptor gain causing aberrant exonization in NR2E3 [89 base pairs (bp)], GPR179 (197 bp), and CNGB3 (73 bp); splicing defects were validated through patient-derived cDNA experiments and/or minigene constructs and rescued by antisense oligonucleotide treatment. Conclusions Deep intronic mutations contribute to missing heritability in retinal dystrophies. Combining results from phenotype-directed gene panel testing, GS, and in silico splice prediction tools can help identify these difficult-to-detect pathogenic deep intronic variants.
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Affiliation(s)
- Matteo Di Scipio
- Genetics and Genomic Biology, The Hospital for Sick Children, Toronto, Canada
| | - Erika Tavares
- Genetics and Genomic Biology, The Hospital for Sick Children, Toronto, Canada
| | - Shriya Deshmukh
- Genetics and Genomic Biology, The Hospital for Sick Children, Toronto, Canada
| | - Isabelle Audo
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
- CHNO des Quinze-Vingts, INSERM-DGOS CIC1423, Paris, France
- University College London Institute of Ophthalmology, London, United Kingdom
| | - Kit Green-Sanderson
- Genetics and Genomic Biology, The Hospital for Sick Children, Toronto, Canada
| | - Yuliya Zubak
- Genetics and Genomic Biology, The Hospital for Sick Children, Toronto, Canada
| | - Fayçal Zine-Eddine
- Genetics and Genomic Biology, The Hospital for Sick Children, Toronto, Canada
| | - Alexander Pearson
- Genetics and Genomic Biology, The Hospital for Sick Children, Toronto, Canada
| | - Anjali Vig
- Genetics and Genomic Biology, The Hospital for Sick Children, Toronto, Canada
| | - Chen Yu Tang
- Genetics and Genomic Biology, The Hospital for Sick Children, Toronto, Canada
| | - Antonio Mollica
- Genetics and Genomic Biology, The Hospital for Sick Children, Toronto, Canada
| | - Jonathan Karas
- Genetics and Genomic Biology, The Hospital for Sick Children, Toronto, Canada
| | - Anupreet Tumber
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, Toronto, Canada
| | - Caberry W. Yu
- Genetics and Genomic Biology, The Hospital for Sick Children, Toronto, Canada
| | - Gail Billingsley
- Genetics and Genomic Biology, The Hospital for Sick Children, Toronto, Canada
| | - Michael D. Wilson
- Genetics and Genomic Biology, The Hospital for Sick Children, Toronto, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Canada
| | - Christina Zeitz
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
| | - Elise Héon
- Genetics and Genomic Biology, The Hospital for Sick Children, Toronto, Canada
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, Toronto, Canada
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Canada
| | - Ajoy Vincent
- Genetics and Genomic Biology, The Hospital for Sick Children, Toronto, Canada
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, Toronto, Canada
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Canada
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89
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Hiraide T, Nakashima M, Ikeda T, Tanaka D, Osaka H, Saitsu H. Identification of a deep intronic POLR3A variant causing inclusion of a pseudoexon derived from an Alu element in Pol III-related leukodystrophy. J Hum Genet 2020; 65:921-925. [PMID: 32483275 DOI: 10.1038/s10038-020-0786-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 05/20/2020] [Indexed: 11/09/2022]
Abstract
Pseudoexon inclusion caused by deep intronic variants is an important genetic cause for various disorders. Here, we present a case of a hypomyelinating leukodystrophy with developmental delay, intellectual disability, autism spectrum disorder, and hypodontia, which are consistent with autosomal recessive POLR3-related leukodystrophy. Whole-exome sequencing identified only a heterozygous missense variant (c.1451G>A) in POLR3A. To explore possible involvement of a deep intronic variant in another allele, we performed whole-genome sequencing of the patient with variant annotation by SpliceAI, a deep-learning-based splicing prediction tool. A deep intronic variant (c.645 + 312C>T) in POLR3A, which was predicted to cause inclusion of a pseudoexon derived from an Alu element, was identified and confirmed by mRNA analysis. These results clearly showed that whole-genome sequencing, in combination with deep-learning-based annotation tools such as SpliceAI, will bring us further benefits in detecting and evaluating possible pathogenic variants in deep intronic regions.
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Affiliation(s)
- Takuya Hiraide
- Department of Biochemistry, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Mitsuko Nakashima
- Department of Biochemistry, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Takahiro Ikeda
- Department of Pediatrics, Jichi Medical School, Shimotsuke, Japan
| | - Daisuke Tanaka
- Department of Pediatrics, Jichi Medical School, Shimotsuke, Japan
| | - Hitoshi Osaka
- Department of Pediatrics, Jichi Medical School, Shimotsuke, Japan
| | - Hirotomo Saitsu
- Department of Biochemistry, Hamamatsu University School of Medicine, Hamamatsu, Japan.
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90
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Stenton SL, Prokisch H. Genetics of mitochondrial diseases: Identifying mutations to help diagnosis. EBioMedicine 2020; 56:102784. [PMID: 32454403 PMCID: PMC7248429 DOI: 10.1016/j.ebiom.2020.102784] [Citation(s) in RCA: 117] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 04/21/2020] [Accepted: 04/22/2020] [Indexed: 12/15/2022] Open
Abstract
Mitochondrial diseases are amongst the most genetically and phenotypically diverse groups of inherited diseases. The vast phenotypic overlap with other disease entities together with the absence of reliable biomarkers act as driving forces for the integration of unbiased methodologies early in the diagnostic algorithm, such as whole exome sequencing (WES) and whole genome sequencing (WGS). Such approaches are used in variant discovery and in combination with high-throughput functional assays such as transcriptomics in simultaneous variant discovery and validation. By capturing all genes, they not only increase the diagnostic rate in heterogenous mitochondrial disease patients, but accelerate novel disease gene discovery, and are valuable in side-stepping the risk of overlooking unexpected or even treatable genetic disease diagnoses.
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Affiliation(s)
- Sarah L Stenton
- Institut für Humangenetik, Klinikum rechts der Isar, Technische Universität München, Trogerstraße 32, 81675 München, Germany; Institute of Neurogenomics, Helmholtz Zentrum München, Ingolstaedter Landstraße 1, D-85764 Neuherberg, Germany
| | - Holger Prokisch
- Institut für Humangenetik, Klinikum rechts der Isar, Technische Universität München, Trogerstraße 32, 81675 München, Germany; Institute of Neurogenomics, Helmholtz Zentrum München, Ingolstaedter Landstraße 1, D-85764 Neuherberg, Germany.
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