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Bozsik A, Butz H, Grolmusz VK, Pócza T, Patócs A, Papp J. Spectrum and genotyping strategies of "dark" genetic matter in germline susceptibility genes of tumor syndromes. Crit Rev Oncol Hematol 2025; 205:104549. [PMID: 39528122 DOI: 10.1016/j.critrevonc.2024.104549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2024] [Revised: 10/23/2024] [Accepted: 10/26/2024] [Indexed: 11/16/2024] Open
Abstract
PURPOSE Despite the widespread use of high-throughput genotyping strategies, certain mutation types remain understudied. We provide an overview of these often overlooked mutation types, with representative examples from common hereditary cancer syndromes. METHODS We conducted a comprehensive review of the literature and locus-specific variant databases to summarize the germline pathogenic variants discovered through non-routine genotyping methods. We evaluated appropriate detection and analysis methods tailored for these specific genetic aberrations. Additionally, we performed in silico splice predictions on deep intronic variants registered in the ClinVar database. RESULTS Our study suggests that, aside from founder mutations, most cases are sporadic. However, we anticipate a relatively high likelihood of splice effects for deep intronic variants. The findings underscore the significant clinical utility of genome sequencing techniques and the importance of applying relevant analysis methods.
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Affiliation(s)
- Anikó Bozsik
- Department of Molecular Genetics, The National Tumor Biology Laboratory, National Institute of Oncology, Comprehensive Cancer Center, Ráth György út 7-9, Budapest H-1122, Hungary; Hereditary Tumours Research Group, Eötvös Loránd Research Network, Nagyvárad tér 4, Budapest H-1089, Hungary.
| | - Henriett Butz
- Department of Molecular Genetics, The National Tumor Biology Laboratory, National Institute of Oncology, Comprehensive Cancer Center, Ráth György út 7-9, Budapest H-1122, Hungary; Hereditary Tumours Research Group, Eötvös Loránd Research Network, Nagyvárad tér 4, Budapest H-1089, Hungary; Department of Laboratory Medicine, Semmelweis University, Ráth György út 7-9, Budapest H-1122, Hungary; Department of Oncology Biobank, National Institute of Oncology, Budapest 1122, Hungary
| | - Vince Kornél Grolmusz
- Department of Molecular Genetics, The National Tumor Biology Laboratory, National Institute of Oncology, Comprehensive Cancer Center, Ráth György út 7-9, Budapest H-1122, Hungary; Hereditary Tumours Research Group, Eötvös Loránd Research Network, Nagyvárad tér 4, Budapest H-1089, Hungary
| | - Tímea Pócza
- Department of Molecular Genetics, The National Tumor Biology Laboratory, National Institute of Oncology, Comprehensive Cancer Center, Ráth György út 7-9, Budapest H-1122, Hungary
| | - Attila Patócs
- Department of Molecular Genetics, The National Tumor Biology Laboratory, National Institute of Oncology, Comprehensive Cancer Center, Ráth György út 7-9, Budapest H-1122, Hungary; Hereditary Tumours Research Group, Eötvös Loránd Research Network, Nagyvárad tér 4, Budapest H-1089, Hungary; Department of Laboratory Medicine, Semmelweis University, Ráth György út 7-9, Budapest H-1122, Hungary
| | - János Papp
- Department of Molecular Genetics, The National Tumor Biology Laboratory, National Institute of Oncology, Comprehensive Cancer Center, Ráth György út 7-9, Budapest H-1122, Hungary; Hereditary Tumours Research Group, Eötvös Loránd Research Network, Nagyvárad tér 4, Budapest H-1089, Hungary
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Zhang C, Shan J, Su J, Wang G, Huo Q, Xu R, Dong M. Clinical and Genetic Analysis of 8 Children With Ornithine Transcarbamylase Deficiency: Two Novel Mutations. Neurol Genet 2024; 10:e200204. [PMID: 39559585 PMCID: PMC11573262 DOI: 10.1212/nxg.0000000000200204] [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: 08/26/2024] [Accepted: 09/04/2024] [Indexed: 11/20/2024]
Abstract
Background and Objectives Cases and studies of neurologic symptoms in children caused by genetic metabolic diseases have been widely reported. Ornithine transcarbamylase deficiency (OTCD) is the most common urea cycle disorder, which is due to mutations in the OTC gene located on chromosome Xp21.1. In this study, we analyzed the clinical and genetic characteristics of 8 Chinese children diagnosed with OTCD. Methods A total of 8 patients (5 male and 3 female) were diagnosed with OTCD by biochemical and molecular analysis between 2015 and 2023. Clinical manifestations, biochemical features, and OTC gene sequencing analysis were reviewed retrospectively. The effect of c.664-1G>C on OTC mRNA synthesis was confirmed by a minigene splicing assay. Results All children were late-onset patients, with a median onset age of 3.6 years (range 1.8-17 years). Neurologic symptoms caused by hyperammonemia include vomiting, coma, dyssomnia, and seizures. The peak plasma ammonia levels ranged from 149 to 4,490 μmol/L, and alanine transaminase levels ranged from 20 to 1316 U/L. Four of them had received CRRT, and only 1 patient was admitted for liver transplantation. By December 2023, 4 patients had survived and 4 were deceased. Blood amino acids or urinary organic acids were detected in 7 cases. All patients underwent whole-exome sequencing, and 2 novel mutations were revealed (P1, c.617dupT and P2, c.664-1G>C). The alteration (c.664-1G>C) leads to the deletion of a 54-bp sequence in the exon 7 of the OTC gene (NM_000531.6: c.664_717del). Discussion Two novel pathogenic variants in the OTC gene were confirmed in 8 Chinese children by biochemical findings and genetic analysis. These findings will provide a better understanding of the diagnosis and treatment of pediatric patients with OTCD.
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Affiliation(s)
- Chen Zhang
- From the Department of Pediatrics (C.Z., J. Shan, J. Su, G.W., R.X., M.D.), Qilu Hospital of Shandong University; Department of Respiratory Disease (J. Su), Children's Hospital affiliated to Shandong University, Jinan; and Department of General Practice (Q.H.), Fourth People's Hospital of Jinan, China
| | - Junli Shan
- From the Department of Pediatrics (C.Z., J. Shan, J. Su, G.W., R.X., M.D.), Qilu Hospital of Shandong University; Department of Respiratory Disease (J. Su), Children's Hospital affiliated to Shandong University, Jinan; and Department of General Practice (Q.H.), Fourth People's Hospital of Jinan, China
| | - Jiaqi Su
- From the Department of Pediatrics (C.Z., J. Shan, J. Su, G.W., R.X., M.D.), Qilu Hospital of Shandong University; Department of Respiratory Disease (J. Su), Children's Hospital affiliated to Shandong University, Jinan; and Department of General Practice (Q.H.), Fourth People's Hospital of Jinan, China
| | - Guan Wang
- From the Department of Pediatrics (C.Z., J. Shan, J. Su, G.W., R.X., M.D.), Qilu Hospital of Shandong University; Department of Respiratory Disease (J. Su), Children's Hospital affiliated to Shandong University, Jinan; and Department of General Practice (Q.H.), Fourth People's Hospital of Jinan, China
| | - Qin Huo
- From the Department of Pediatrics (C.Z., J. Shan, J. Su, G.W., R.X., M.D.), Qilu Hospital of Shandong University; Department of Respiratory Disease (J. Su), Children's Hospital affiliated to Shandong University, Jinan; and Department of General Practice (Q.H.), Fourth People's Hospital of Jinan, China
| | - Rui Xu
- From the Department of Pediatrics (C.Z., J. Shan, J. Su, G.W., R.X., M.D.), Qilu Hospital of Shandong University; Department of Respiratory Disease (J. Su), Children's Hospital affiliated to Shandong University, Jinan; and Department of General Practice (Q.H.), Fourth People's Hospital of Jinan, China
| | - Meng Dong
- From the Department of Pediatrics (C.Z., J. Shan, J. Su, G.W., R.X., M.D.), Qilu Hospital of Shandong University; Department of Respiratory Disease (J. Su), Children's Hospital affiliated to Shandong University, Jinan; and Department of General Practice (Q.H.), Fourth People's Hospital of Jinan, China
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3
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Takaoka S, Jaso-Vera ME, Ruan X. Disrupted Post-Transcriptional Regulation of Gene Expression as a Hallmark of Fatty Liver Progression. Int J Mol Sci 2024; 25:11054. [PMID: 39456836 PMCID: PMC11507451 DOI: 10.3390/ijms252011054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2024] [Revised: 10/08/2024] [Accepted: 10/10/2024] [Indexed: 10/28/2024] Open
Abstract
It is known that both transcriptional and post-transcriptional mechanisms control messenger RNA (mRNA) levels. Compared to transcriptional regulations, our understanding of how post-transcriptional regulations adapt during fatty liver progression at the whole-transcriptome level is unclear. While traditional RNA-seq analysis uses only reads mapped to exons to determine gene expression, recent studies support the idea that intron-mapped reads can be reliably used to estimate gene transcription. In this study, we analyzed differential gene expression at both the exon and intron levels using two liver RNA-seq datasets from mice that were fed a high-fat diet for seven weeks (mild fatty liver) or thirty weeks (severe fatty liver). We found that the correlation between gene transcription and mature mRNA levels was much lower in mice with mild fatty liver as compared with mice with severe fatty liver. This result indicates broad post-transcriptional regulations for early fatty liver and such regulations are compromised for severe fatty liver. Specifically, gene ontology analysis revealed that genes involved in synapse organization and cell adhesion were transcriptionally upregulated, while their mature mRNAs were unaffected in mild fatty liver. Further characterization of post-transcriptionally suppressed genes in early fatty liver revealed that their mRNAs harbor a significantly longer 3' UTR, one of the major features that may subject RNA transcripts to nonsense-mediated RNA decay (NMD). We further show that the expression of representative genes that were post-transcriptionally suppressed were upregulated in mice with a hepatocyte-specific defect of NMD. Finally, we provide data supporting a time-dependent decrease in NMD activity in the liver of a diet-induced metabolic-dysfunction-associated fatty liver disease mouse model. In summary, our study supports the conclusion that NMD is essential in preventing unwanted/harmful gene expression at the early stage of fatty liver and such a mechanism is lost due to decreased NMD activity in mice with severe fatty liver.
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Affiliation(s)
- Shohei Takaoka
- Division of Endocrinology, Diabetes and Metabolism, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; (S.T.); (M.E.J.-V.)
- Institute for Fundamental Biomedical Research, Johns Hopkins All Children’s Hospital, St. Petersburg, FL 33701, USA
| | - Marcos E. Jaso-Vera
- Division of Endocrinology, Diabetes and Metabolism, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; (S.T.); (M.E.J.-V.)
- Institute for Fundamental Biomedical Research, Johns Hopkins All Children’s Hospital, St. Petersburg, FL 33701, USA
| | - Xiangbo Ruan
- Division of Endocrinology, Diabetes and Metabolism, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; (S.T.); (M.E.J.-V.)
- Institute for Fundamental Biomedical Research, Johns Hopkins All Children’s Hospital, St. Petersburg, FL 33701, USA
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Wai HA, Svobodova E, Herrera NR, Douglas AGL, Holloway JW, Baralle FE, Baralle M, Baralle D. Tailored antisense oligonucleotides designed to correct aberrant splicing reveal actionable groups of mutations for rare genetic disorders. Exp Mol Med 2024; 56:1816-1825. [PMID: 39085356 PMCID: PMC11371919 DOI: 10.1038/s12276-024-01292-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2024] [Revised: 05/09/2024] [Accepted: 05/14/2024] [Indexed: 08/02/2024] Open
Abstract
Effective translation of rare disease diagnosis knowledge into therapeutic applications is achievable within a reasonable timeframe; where mutations are amenable to current antisense oligonucleotide technology. In our study, we identified five distinct types of abnormal splice-causing mutations in patients with rare genetic disorders and developed a tailored antisense oligonucleotide for each mutation type using phosphorodiamidate morpholino oligomers with or without octa-guanidine dendrimers and 2'-O-methoxyethyl phosphorothioate. We observed variations in treatment effects and efficiencies, influenced by both the chosen chemistry and the specific nature of the aberrant splicing patterns targeted for correction. Our study demonstrated the successful correction of all five different types of aberrant splicing. Our findings reveal that effective correction of aberrant splicing can depend on altering the chemical composition of oligonucleotides and suggest a fast, efficient, and feasible approach for developing personalized therapeutic interventions for genetic disorders within short time frames.
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Affiliation(s)
- Htoo A Wai
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Eliska Svobodova
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, UK
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
- Department of Clinical Immunology and Allergology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Natalia Romero Herrera
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Andrew G L Douglas
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, UK
- Oxford Centre for Genomic Medicine, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - John W Holloway
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Francisco E Baralle
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, UK
- Fondazione Fegato, Area Science Park Basovizza, 34149, Trieste, Italy
| | - Marco Baralle
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, UK
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Padriciano 99, 34149, Trieste, Italy
| | - Diana Baralle
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, UK.
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Mura-Escorche G, Perdomo-Ramírez A, Ramos-Trujillo E, Trujillo-Frías CJ, Claverie-Martín F. Characterization of pre-mRNA Splicing Defects Caused by CLCN5 and OCRL Mutations and Identification of Novel Variants Associated with Dent Disease. Biomedicines 2023; 11:3082. [PMID: 38002082 PMCID: PMC10669864 DOI: 10.3390/biomedicines11113082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 11/08/2023] [Accepted: 11/13/2023] [Indexed: 11/26/2023] Open
Abstract
Dent disease (DD) is an X-linked renal tubulopathy characterized by low-molecular-weight proteinuria, hypercalciuria, nephrocalcinosis, nephrolithiasis and progressive renal failure. Two-thirds of cases are associated with inactivating variants in the CLCN5 gene (Dent disease 1, DD1) and a few present variants in the OCRL gene (Dent disease 2, DD2). The aim of the present study was to test the effect on the pre-mRNA splicing process of DD variants, described here or in the literature, and describe the clinical and genotypic features of thirteen unrelated patients with suspected DD. All patients presented tubular proteinuria, ten presented hypercalciuria and five had nephrolithiasis or nephrocalcinosis. CLCN5 and OCRL genes were analyzed by Sanger sequencing. Nine patients showed variants in CLCN5 and four in OCRL; eight of these were new. Bioinformatics tools were used to select fifteen variants with a potential effect on pre-mRNA splicing from our patients' group and from the literature, and were experimentally tested using minigene assays. Results showed that three exonic missense mutations and two intronic variants affect the mRNA splicing process. Our findings widen the genotypic spectrum of DD and provide insight into the impact of variants causing DD.
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Affiliation(s)
- Glorián Mura-Escorche
- Unidad de Investigación, Grupo RenalTube, Hospital Universitario Nuestra Señora de Candelaria, 38010 Santa Cruz de Tenerife, Spain; (G.M.-E.); (A.P.-R.); (C.J.T.-F.)
- Departamento de Medicina Interna, Dermatología y Psiquiatría, Facultad de Medicina, Universidad de la Laguna, 38071 Santa Cruz de Tenerife, Spain
| | - Ana Perdomo-Ramírez
- Unidad de Investigación, Grupo RenalTube, Hospital Universitario Nuestra Señora de Candelaria, 38010 Santa Cruz de Tenerife, Spain; (G.M.-E.); (A.P.-R.); (C.J.T.-F.)
| | - Elena Ramos-Trujillo
- Unidad de Investigación, Grupo RenalTube, Hospital Universitario Nuestra Señora de Candelaria, 38010 Santa Cruz de Tenerife, Spain; (G.M.-E.); (A.P.-R.); (C.J.T.-F.)
- Departamento de Medicina Física y Farmacología, Facultad de Medicina, Universidad de la Laguna, 38071 Santa Cruz de Tenerife, Spain
| | - Carmen Jane Trujillo-Frías
- Unidad de Investigación, Grupo RenalTube, Hospital Universitario Nuestra Señora de Candelaria, 38010 Santa Cruz de Tenerife, Spain; (G.M.-E.); (A.P.-R.); (C.J.T.-F.)
| | - Félix Claverie-Martín
- Unidad de Investigación, Grupo RenalTube, Hospital Universitario Nuestra Señora de Candelaria, 38010 Santa Cruz de Tenerife, Spain; (G.M.-E.); (A.P.-R.); (C.J.T.-F.)
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Yang JY, Wang WQ, Han MY, Huang SS, Wang GJ, Su Y, Xu JC, Fu Y, Kang DY, Yang K, Zhang X, Liu X, Gao X, Yuan YY, Dai P. Addition of an affected family member to a previously ascertained autosomal recessive nonsyndromic hearing loss pedigree and systematic phenotype-genotype analysis of splice-site variants in MYO15A. BMC Med Genomics 2022; 15:241. [PMCID: PMC9673454 DOI: 10.1186/s12920-022-01368-9] [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: 06/17/2022] [Accepted: 09/29/2022] [Indexed: 11/19/2022] Open
Abstract
Pathogenic variants in MYO15A are known to cause autosomal recessive nonsyndromic hearing loss (ARNSHL), DFNB3. We have previously reported on one ARNSHL family including two affected siblings and identified MYO15A c.5964+3G > A and c.8375 T > C (p.Val2792Ala) as the possible deafness-causing variants. Eight year follow up identified one new affected individual in this family, who also showed congenital, severe to profound sensorineural hearing loss. By whole exome sequencing, we identified a new splice-site variant c.5531+1G > C (maternal allele), in a compound heterozygote with previously identified missense variant c.8375 T > C (p.Val2792Ala) (paternal allele) in MYO15A as the disease-causing variants. The new affected individual underwent unilateral cochlear implantation at the age of 1 year, and 5 year follow-up showed satisfactory speech and language outcomes. Our results further indicate that MYO15A-associated hearing loss is good candidates for cochlear implantation, which is in accordance with previous report. In light of our findings and review of the literatures, 58 splice-site variants in MYO15A are correlated with a severe deafness phenotype, composed of 46 canonical splice-site variants and 12 non-canonical splice-site variants.
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Affiliation(s)
- Jin-Yuan Yang
- grid.488137.10000 0001 2267 2324College of Otolaryngology Head and Neck Surgery, Chinese PLA General Hospital, Chinese PLA Medical School, 28 Fuxing Road, Beijing, 100853 People’s Republic of China ,grid.419897.a0000 0004 0369 313XNational Clinical Research Center for Otolaryngologic Diseases, State Key Lab of Hearing Science, Ministry of Education, Beijing, People’s Republic of China ,Beijing Key Lab of Hearing Impairment Prevention and Treatment, Beijing, People’s Republic of China
| | - Wei-Qian Wang
- grid.488137.10000 0001 2267 2324College of Otolaryngology Head and Neck Surgery, Chinese PLA General Hospital, Chinese PLA Medical School, 28 Fuxing Road, Beijing, 100853 People’s Republic of China ,grid.419897.a0000 0004 0369 313XNational Clinical Research Center for Otolaryngologic Diseases, State Key Lab of Hearing Science, Ministry of Education, Beijing, People’s Republic of China ,Beijing Key Lab of Hearing Impairment Prevention and Treatment, Beijing, People’s Republic of China ,grid.488137.10000 0001 2267 2324Department of Otolaryngology, PLA Rocket Force Characteristic Medical Center, 16# XinWai Da Jie, Beijing, 100088 People’s Republic of China
| | - Ming-Yu Han
- grid.488137.10000 0001 2267 2324College of Otolaryngology Head and Neck Surgery, Chinese PLA General Hospital, Chinese PLA Medical School, 28 Fuxing Road, Beijing, 100853 People’s Republic of China ,grid.419897.a0000 0004 0369 313XNational Clinical Research Center for Otolaryngologic Diseases, State Key Lab of Hearing Science, Ministry of Education, Beijing, People’s Republic of China ,Beijing Key Lab of Hearing Impairment Prevention and Treatment, Beijing, People’s Republic of China
| | - Sha-Sha Huang
- grid.488137.10000 0001 2267 2324College of Otolaryngology Head and Neck Surgery, Chinese PLA General Hospital, Chinese PLA Medical School, 28 Fuxing Road, Beijing, 100853 People’s Republic of China ,grid.419897.a0000 0004 0369 313XNational Clinical Research Center for Otolaryngologic Diseases, State Key Lab of Hearing Science, Ministry of Education, Beijing, People’s Republic of China ,Beijing Key Lab of Hearing Impairment Prevention and Treatment, Beijing, People’s Republic of China
| | - Guo-Jian Wang
- grid.488137.10000 0001 2267 2324College of Otolaryngology Head and Neck Surgery, Chinese PLA General Hospital, Chinese PLA Medical School, 28 Fuxing Road, Beijing, 100853 People’s Republic of China ,grid.419897.a0000 0004 0369 313XNational Clinical Research Center for Otolaryngologic Diseases, State Key Lab of Hearing Science, Ministry of Education, Beijing, People’s Republic of China ,Beijing Key Lab of Hearing Impairment Prevention and Treatment, Beijing, People’s Republic of China
| | - Yu Su
- Department of Otolaryngology, Head and Neck Surgery, Chinese PLA General Hospital Affiliated Hainan Hospital, Jianglin Road, Sanya, 572013 People’s Republic of China ,Hainan Province Clinical Research Center for Otolaryngologic and Head and Neck Diseases, Jianglin Road, Sanya, 572013 People’s Republic of China
| | - Jin-Cao Xu
- grid.488137.10000 0001 2267 2324Department of Otolaryngology, PLA Rocket Force Characteristic Medical Center, 16# XinWai Da Jie, Beijing, 100088 People’s Republic of China
| | - Ying Fu
- grid.27255.370000 0004 1761 1174Department of Otorhinolaryngology, Qilu Hospital (Qingdao), Cheeloo College of Medicine, Shandong University, 758 Hefei Road, Qingdao, 266035 Shandong People’s Republic of China
| | - Dong-Yang Kang
- grid.488137.10000 0001 2267 2324College of Otolaryngology Head and Neck Surgery, Chinese PLA General Hospital, Chinese PLA Medical School, 28 Fuxing Road, Beijing, 100853 People’s Republic of China ,grid.419897.a0000 0004 0369 313XNational Clinical Research Center for Otolaryngologic Diseases, State Key Lab of Hearing Science, Ministry of Education, Beijing, People’s Republic of China ,Beijing Key Lab of Hearing Impairment Prevention and Treatment, Beijing, People’s Republic of China
| | - Kun Yang
- grid.488137.10000 0001 2267 2324Postgraduate Training Base of Jinzhou Medical University, The PLA Rocket Force Characteristic Medical Center, 16# XinWai Da Jie, Beijing, 100088 People’s Republic of China
| | - Xin Zhang
- grid.488137.10000 0001 2267 2324College of Otolaryngology Head and Neck Surgery, Chinese PLA General Hospital, Chinese PLA Medical School, 28 Fuxing Road, Beijing, 100853 People’s Republic of China ,grid.419897.a0000 0004 0369 313XNational Clinical Research Center for Otolaryngologic Diseases, State Key Lab of Hearing Science, Ministry of Education, Beijing, People’s Republic of China ,Beijing Key Lab of Hearing Impairment Prevention and Treatment, Beijing, People’s Republic of China
| | - Xing Liu
- grid.488137.10000 0001 2267 2324Department of Otolaryngology, PLA Rocket Force Characteristic Medical Center, 16# XinWai Da Jie, Beijing, 100088 People’s Republic of China
| | - Xue Gao
- grid.488137.10000 0001 2267 2324College of Otolaryngology Head and Neck Surgery, Chinese PLA General Hospital, Chinese PLA Medical School, 28 Fuxing Road, Beijing, 100853 People’s Republic of China ,grid.419897.a0000 0004 0369 313XNational Clinical Research Center for Otolaryngologic Diseases, State Key Lab of Hearing Science, Ministry of Education, Beijing, People’s Republic of China ,Beijing Key Lab of Hearing Impairment Prevention and Treatment, Beijing, People’s Republic of China ,grid.488137.10000 0001 2267 2324Department of Otolaryngology, PLA Rocket Force Characteristic Medical Center, 16# XinWai Da Jie, Beijing, 100088 People’s Republic of China
| | - Yong-Yi Yuan
- grid.488137.10000 0001 2267 2324College of Otolaryngology Head and Neck Surgery, Chinese PLA General Hospital, Chinese PLA Medical School, 28 Fuxing Road, Beijing, 100853 People’s Republic of China ,grid.419897.a0000 0004 0369 313XNational Clinical Research Center for Otolaryngologic Diseases, State Key Lab of Hearing Science, Ministry of Education, Beijing, People’s Republic of China ,Beijing Key Lab of Hearing Impairment Prevention and Treatment, Beijing, People’s Republic of China
| | - Pu Dai
- grid.488137.10000 0001 2267 2324College of Otolaryngology Head and Neck Surgery, Chinese PLA General Hospital, Chinese PLA Medical School, 28 Fuxing Road, Beijing, 100853 People’s Republic of China ,grid.419897.a0000 0004 0369 313XNational Clinical Research Center for Otolaryngologic Diseases, State Key Lab of Hearing Science, Ministry of Education, Beijing, People’s Republic of China ,Beijing Key Lab of Hearing Impairment Prevention and Treatment, Beijing, People’s Republic of China
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Bryen SJ, Yuen M, Joshi H, Dawes R, Zhang K, Lu JK, Jones KJ, Liang C, Wong WK, Peduto AJ, Waddell LB, Evesson FJ, Cooper ST. Prevalence, parameters, and pathogenic mechanisms for splice-altering acceptor variants that disrupt the AG exclusion zone. HGG ADVANCES 2022; 3:100125. [PMID: 35847480 PMCID: PMC9284458 DOI: 10.1016/j.xhgg.2022.100125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 06/19/2022] [Indexed: 10/26/2022] Open
Abstract
Predicting the pathogenicity of acceptor splice-site variants outside the essential AG is challenging, due to high sequence diversity of the extended splice-site region. Critical analysis of 24,445 intronic extended acceptor splice-site variants reported in ClinVar and the Leiden Open Variation Database (LOVD) demonstrates 41.9% of pathogenic variants create an AG dinucleotide between the predicted branchpoint and acceptor (AG-creating variants in the AG exclusion zone), 28.4% result in loss of a pyrimidine at the -3 position, and 15.1% result in loss of one or more pyrimidines in the polypyrimidine tract. Pathogenicity of AG-creating variants was highly influenced by their position. We define a high-risk zone for pathogenicity: > 6 nucleotides downstream of the predicted branchpoint and >5 nucleotides upstream from the acceptor, where 93.1% of pathogenic AG-creating variants arise and where naturally occurring AG dinucleotides are concordantly depleted (5.8% of natural AGs). SpliceAI effectively predicts pathogenicity of AG-creating variants, achieving 95% sensitivity and 69% specificity. We highlight clinical examples showing contrasting mechanisms for mis-splicing arising from AG variants: (1) cryptic acceptor created; (2) splicing silencer created: an introduced AG silences the acceptor, resulting in exon skipping, intron retention, and/or use of an alternative existing cryptic acceptor; and (3) splicing silencer disrupted: loss of a deep intronic AG activates inclusion of a pseudo-exon. In conclusion, we establish AG-creating variants as a common class of pathogenic extended acceptor variant and outline factors conferring critical risk for mis-splicing for AG-creating variants in the AG exclusion zone, between the branchpoint and acceptor.
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Affiliation(s)
- Samantha J. Bryen
- Kids Neuroscience Centre, Kids Research, The Children’s Hospital at Westmead, Locked Bag 4001, Westmead, NSW 2145, Australia
- Discipline of Child and Adolescent Health, Faculty of Medicine and Health, The University of Sydney, Locked Bag 4001, Westmead, NSW 2145, Australia
- Functional Neuromics, Children’s Medical Research Institute, The University of Sydney, Locked Bag 4001, Westmead, NSW 2145, Australia
| | - Michaela Yuen
- Kids Neuroscience Centre, Kids Research, The Children’s Hospital at Westmead, Locked Bag 4001, Westmead, NSW 2145, Australia
- Discipline of Child and Adolescent Health, Faculty of Medicine and Health, The University of Sydney, Locked Bag 4001, Westmead, NSW 2145, Australia
| | - Himanshu Joshi
- Kids Neuroscience Centre, Kids Research, The Children’s Hospital at Westmead, Locked Bag 4001, Westmead, NSW 2145, Australia
- Functional Neuromics, Children’s Medical Research Institute, The University of Sydney, Locked Bag 4001, Westmead, NSW 2145, Australia
| | - Ruebena Dawes
- Kids Neuroscience Centre, Kids Research, The Children’s Hospital at Westmead, Locked Bag 4001, Westmead, NSW 2145, Australia
- Discipline of Child and Adolescent Health, Faculty of Medicine and Health, The University of Sydney, Locked Bag 4001, Westmead, NSW 2145, Australia
| | - Katharine Zhang
- Kids Neuroscience Centre, Kids Research, The Children’s Hospital at Westmead, Locked Bag 4001, Westmead, NSW 2145, Australia
- Functional Neuromics, Children’s Medical Research Institute, The University of Sydney, Locked Bag 4001, Westmead, NSW 2145, Australia
| | - Jessica K. Lu
- Kids Neuroscience Centre, Kids Research, The Children’s Hospital at Westmead, Locked Bag 4001, Westmead, NSW 2145, Australia
- Discipline of Child and Adolescent Health, Faculty of Medicine and Health, The University of Sydney, Locked Bag 4001, Westmead, NSW 2145, Australia
| | - Kristi J. Jones
- Discipline of Child and Adolescent Health, Faculty of Medicine and Health, The University of Sydney, Locked Bag 4001, Westmead, NSW 2145, Australia
- Department of Clinical Genetics, Children’s Hospital at Westmead, Westmead, NSW 2145, Australia
| | - Christina Liang
- Department of Neurology, Royal North Shore Hospital, St Leonards, NSW 2065, Australia
- Department of Neurogenetics, Northern Clinical School, Kolling Institute, University of Sydney, NSW 2065, Australia
| | - Wui-Kwan Wong
- Kids Neuroscience Centre, Kids Research, The Children’s Hospital at Westmead, Locked Bag 4001, Westmead, NSW 2145, Australia
- Discipline of Child and Adolescent Health, Faculty of Medicine and Health, The University of Sydney, Locked Bag 4001, Westmead, NSW 2145, Australia
| | - Anthony J. Peduto
- Department of Radiology, Westmead Hospital, Western Clinical School, University of Sydney, Westmead, NSW 2145, Australia
| | - Leigh B. Waddell
- Kids Neuroscience Centre, Kids Research, The Children’s Hospital at Westmead, Locked Bag 4001, Westmead, NSW 2145, Australia
- Discipline of Child and Adolescent Health, Faculty of Medicine and Health, The University of Sydney, Locked Bag 4001, Westmead, NSW 2145, Australia
| | - Frances J. Evesson
- Kids Neuroscience Centre, Kids Research, The Children’s Hospital at Westmead, Locked Bag 4001, Westmead, NSW 2145, Australia
- Functional Neuromics, Children’s Medical Research Institute, The University of Sydney, Locked Bag 4001, Westmead, NSW 2145, Australia
| | - Sandra T. Cooper
- Kids Neuroscience Centre, Kids Research, The Children’s Hospital at Westmead, Locked Bag 4001, Westmead, NSW 2145, Australia
- Discipline of Child and Adolescent Health, Faculty of Medicine and Health, The University of Sydney, Locked Bag 4001, Westmead, NSW 2145, Australia
- Functional Neuromics, Children’s Medical Research Institute, The University of Sydney, Locked Bag 4001, Westmead, NSW 2145, Australia
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8
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Blakes AJM, Wai HA, Davies I, Moledina HE, Ruiz A, Thomas T, Bunyan D, Thomas NS, Burren CP, Greenhalgh L, Lees M, Pichini A, Smithson SF, Taylor Tavares AL, O'Donovan P, Douglas AGL, Whiffin N, Baralle D, Lord J. A systematic analysis of splicing variants identifies new diagnoses in the 100,000 Genomes Project. Genome Med 2022; 14:79. [PMID: 35883178 PMCID: PMC9327385 DOI: 10.1186/s13073-022-01087-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 07/13/2022] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Genomic variants which disrupt splicing are a major cause of rare genetic diseases. However, variants which lie outside of the canonical splice sites are difficult to interpret clinically. Improving the clinical interpretation of non-canonical splicing variants offers a major opportunity to uplift diagnostic yields from whole genome sequencing data. METHODS Here, we examine the landscape of splicing variants in whole-genome sequencing data from 38,688 individuals in the 100,000 Genomes Project and assess the contribution of non-canonical splicing variants to rare genetic diseases. We use a variant-level constraint metric (the mutability-adjusted proportion of singletons) to identify constrained functional variant classes near exon-intron junctions and at putative splicing branchpoints. To identify new diagnoses for individuals with unsolved rare diseases in the 100,000 Genomes Project, we identified individuals with de novo single-nucleotide variants near exon-intron boundaries and at putative splicing branchpoints in known disease genes. We identified candidate diagnostic variants through manual phenotype matching and confirmed new molecular diagnoses through clinical variant interpretation and functional RNA studies. RESULTS We show that near-splice positions and splicing branchpoints are highly constrained by purifying selection and harbour potentially damaging non-coding variants which are amenable to systematic analysis in sequencing data. From 258 de novo splicing variants in known rare disease genes, we identify 35 new likely diagnoses in probands with an unsolved rare disease. To date, we have confirmed a new diagnosis for six individuals, including four in whom RNA studies were performed. CONCLUSIONS Overall, we demonstrate the clinical value of examining non-canonical splicing variants in individuals with unsolved rare diseases.
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Affiliation(s)
- Alexander J M Blakes
- Faculty of Medicine, Human Development and Health, University of Southampton, Southampton, UK
- Faculty of Medicine, National Heart and Lung Institute, Imperial College London, London, UK
| | - Htoo A Wai
- Faculty of Medicine, Human Development and Health, University of Southampton, Southampton, UK
| | - Ian Davies
- Cancer Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Hassan E Moledina
- Faculty of Medicine, Human Development and Health, University of Southampton, Southampton, UK
| | - April Ruiz
- Wessex Clinical Genetics Service, Princess Anne Hospital, Southampton, UK
| | - Tessy Thomas
- Wessex Clinical Genetics Service, Princess Anne Hospital, Southampton, UK
| | - David Bunyan
- Wessex Regional Genetics Laboratory, Salisbury District Hospital, Salisbury, UK
- Faculty of Medicine, University of Southampton, Southampton, UK
| | - N Simon Thomas
- Wessex Regional Genetics Laboratory, Salisbury District Hospital, Salisbury, UK
- Faculty of Medicine, University of Southampton, Southampton, UK
| | - Christine P Burren
- Department of Paediatric Endocrinology and Diabetes, University Hospitals Bristol and Weston NHS Foundation Trust, Bristol, UK
- Bristol Medical School, Department of Translational Health Sciences, University of Bristol, Bristol, UK
| | - Lynn Greenhalgh
- Liverpool Centre for Genomic Medicine, Crown Street, Liverpool, UK
| | - Melissa Lees
- North East Thames Regional Genomics Service, Great Ormond Street Hospital, London, UK
| | - Amanda Pichini
- Department of Clinical Genetics, University Hospitals Bristol and Weston Foundation Trust, Bristol, UK
- Genomics England, Dawson Hall, Charterhouse Square, London, UK
| | - Sarah F Smithson
- Department of Clinical Genetics, University Hospitals Bristol and Weston Foundation Trust, Bristol, UK
| | - Ana Lisa Taylor Tavares
- Genomics England, Dawson Hall, Charterhouse Square, London, UK
- Cambridge University Hospitals NHS Foundation Trust, Cambridge Biomedical Campus, Hills Road, Cambridge, UK
| | - Peter O'Donovan
- Genomics England, Dawson Hall, Charterhouse Square, London, UK
| | - Andrew G L Douglas
- Faculty of Medicine, Human Development and Health, University of Southampton, Southampton, UK
- Oxford Centre for Genomic Medicine, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Nicola Whiffin
- Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Diana Baralle
- Faculty of Medicine, Human Development and Health, University of Southampton, Southampton, UK
- Wessex Clinical Genetics Service, Princess Anne Hospital, Southampton, UK
| | - Jenny Lord
- Faculty of Medicine, Human Development and Health, University of Southampton, Southampton, UK.
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9
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Wai HA, Constable M, Drewes C, Davies IC, Svobodova E, Dempsey E, Saggar A, Homfray T, Mansour S, Douzgou S, Barr K, Mercer C, Hunt D, Douglas AGL, Baralle D. Short amplicon reverse transcription-polymerase chain reaction detects aberrant splicing in genes with low expression in blood missed by ribonucleic acid sequencing analysis for clinical diagnosis. Hum Mutat 2022; 43:963-970. [PMID: 35476365 PMCID: PMC9325405 DOI: 10.1002/humu.24378] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 03/28/2022] [Accepted: 03/31/2022] [Indexed: 12/03/2022]
Abstract
Use of blood RNA sequencing (RNA-seq) as a splicing analysis tool for clinical interpretation of variants of uncertain significance (VUSs) found via whole-genome and exome sequencing can be difficult for genes that have low expression in the blood due to insufficient read count coverage aligned to specific genes of interest. Here, we present a short amplicon reverse transcription-polymerase chain reaction(RT-PCR) for the detection of genes with low blood expression. Short amplicon RT-PCR, is designed to span three exons where an exon harboring a variant is flanked by one upstream and one downstream exon. We tested short amplicon RT-PCRs for genes that have median transcripts per million (TPM) values less than one according to the genotype-tissue expression database. Median TPM values of genes analyzed in this study are SYN1 = 0.8549, COL1A1 = 0.6275, TCF4 = 0.4009, DSP = .2894, TTN = 0.2851, COL5A2 = 0.1036, TERT = 0.04452, NTRK2 = 0.0344, ABCA4 = 0.00744, PRPH = 0, and WT1 = 0. All these genes show insufficient exon-spanning read coverage in our RNA-seq data to allow splicing analysis. We successfully detected all genes tested except PRPH and WT1. Aberrant splicing was detected in SYN1, TCF4, NTRK2, TTN, and TERT VUSs. Therefore, our results show short amplicon RT-PCR is a useful alternative for the analysis of splicing events in genes with low TPM in blood RNA for clinical diagnostics.
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Affiliation(s)
- Htoo A. Wai
- Human Development and Health, Faculty of Medicine, Southampton General HospitalUniversity of SouthamptonSouthamptonUK
| | - Matthew Constable
- Human Development and Health, Faculty of Medicine, Southampton General HospitalUniversity of SouthamptonSouthamptonUK
| | - Cosima Drewes
- Human Development and Health, Faculty of Medicine, Southampton General HospitalUniversity of SouthamptonSouthamptonUK
| | - Ian C. Davies
- Human Development and Health, Faculty of Medicine, Southampton General HospitalUniversity of SouthamptonSouthamptonUK
| | - Eliska Svobodova
- Department of Experimental Biology, Faculty of ScienceMasaryk UniversityBrnoCzech Republic
| | - Esther Dempsey
- Department of Clinical GeneticsSt George's University of LondonLondonUK
| | - Anand Saggar
- Department of Clinical GeneticsSt George's University of LondonLondonUK
| | - Tessa Homfray
- Department of Clinical GeneticsSt George's University of LondonLondonUK
| | - Sahar Mansour
- Department of Clinical GeneticsSt George's University of LondonLondonUK
| | - Sofia Douzgou
- Manchester Centre for Genomic Medicine, St Mary's Hospital, Manchester University NHS Foundation TrustHealth Innovation ManchesterManchesterUK,Division of Evolution and Genomic Sciences, Faculty of Biology, Medicine and Health, School of Biological SciencesUniversity of ManchesterManchesterUK
| | - Kate Barr
- Bristol Regional Clinical Genetics ServiceSt Michael's HospitalBristolUK
| | - Catherine Mercer
- Department of Experimental Biology, Faculty of ScienceMasaryk UniversityBrnoCzech Republic
| | - David Hunt
- Human Development and Health, Faculty of Medicine, Southampton General HospitalUniversity of SouthamptonSouthamptonUK,Wessex Clinical Genetics ServiceUniversity Hospital Southampton NHS Foundation TrustSouthamptonUK
| | - Andrew G. L. Douglas
- Human Development and Health, Faculty of Medicine, Southampton General HospitalUniversity of SouthamptonSouthamptonUK,Wessex Clinical Genetics ServiceUniversity Hospital Southampton NHS Foundation TrustSouthamptonUK
| | - Diana Baralle
- Human Development and Health, Faculty of Medicine, Southampton General HospitalUniversity of SouthamptonSouthamptonUK,Wessex Clinical Genetics ServiceUniversity Hospital Southampton NHS Foundation TrustSouthamptonUK
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10
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Wang X, Gardner K, Tegegn MB, Dalgard CL, Alba C, Menzel S, Patel H, Pirooznia M, Fu YP, Seifuddin FT, Thein SL. Genetic variants of PKLR are associated with acute pain in sickle cell disease. Blood Adv 2022; 6:3535-3540. [PMID: 35271708 PMCID: PMC9198922 DOI: 10.1182/bloodadvances.2021006668] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 03/01/2022] [Indexed: 11/20/2022] Open
Abstract
Acute pain, the most prominent complication of sickle cell disease (SCD), results from vaso-occlusion triggered by sickling of deoxygenated red blood cells (RBCs). Concentration of 2,3-diphosphoglycerate (2,3-DPG) in RBCs promotes deoxygenation by preferentially binding to the low-affinity T conformation of HbS. 2,3-DPG is an intermediate substrate in the glycolytic pathway in which pyruvate kinase (gene PKLR, protein PKR) is a rate-limiting enzyme; variants in PKLR may affect PKR activity, 2,3-DPG levels in RBCs, RBC sickling, and acute pain episodes (APEs). We performed a candidate gene association study using 2 cohorts: 242 adult SCD-HbSS patients and 977 children with SCD-HbSS or SCD-HbSβ0 thalassemia. Seven of 47 PKLR variants evaluated in the adult cohort were associated with hospitalization: intron 4, rs2071053; intron 2, rs8177970, rs116244351, rs114455416, rs12741350, rs3020781, and rs8177964. All 7 variants showed consistent effect directions in both cohorts and remained significant in weighted Fisher's meta-analyses of the adult and pediatric cohorts using P < .0071 as threshold to correct for multiple testing. Allele-specific expression analyses in an independent cohort of 52 SCD adults showed that the intronic variants are likely to influence APE by affecting expression of PKLR, although the causal variant and mechanism are not defined.
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Affiliation(s)
- Xunde Wang
- Sickle Cell Branch, National Heart, Lung, and Blood Institute, National Institutes of Health (NIH), Bethesda, MD
| | - Kate Gardner
- School of Cancer & Pharmaceutical Sciences, King’s College London, London, United Kingdom
- Department of Haematology, Guy and St Thomas’ NHS Foundation Trust, London, United Kingdom
| | - Mickias B. Tegegn
- Sickle Cell Branch, National Heart, Lung, and Blood Institute, National Institutes of Health (NIH), Bethesda, MD
| | - Clifton L. Dalgard
- Department of Anatomy, Physiology & Genetics, and
- The American Genome Center, Uniformed Services University of the Health Sciences, Bethesda, MD
| | - Camille Alba
- The American Genome Center, Uniformed Services University of the Health Sciences, Bethesda, MD
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD
| | - Stephan Menzel
- School of Cancer & Pharmaceutical Sciences, King’s College London, London, United Kingdom
| | - Hamel Patel
- Department of Biostatistics and Health Informatics, Institute of Psychiatry, Psychology, and Neuroscience, King’s College London, London, United Kingdom
| | | | - Yi-Ping Fu
- Office of Biostatistics Research, National Heart, Lung, and Blood Institute, NIH, Bethesda, MD
| | | | - Swee Lay Thein
- Sickle Cell Branch, National Heart, Lung, and Blood Institute, National Institutes of Health (NIH), Bethesda, MD
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11
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Marin Rubio LA, Aroca-Aguilar JD, Luis-Hidalgo M, Escribano J, Ontañon J. RNA and protein expression analysis of HLA-DQB1*03:01:01:21Q allele: A null allele renamed as HLA-DQB1*03:01:01:21N. HLA 2022; 99:160-166. [PMID: 34997833 DOI: 10.1111/tan.14537] [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: 10/14/2021] [Revised: 12/03/2021] [Accepted: 01/04/2022] [Indexed: 12/15/2022]
Abstract
The characterization of the expression profile of HLA questionable alleles (Q) is clinically relevant in allogeneic hematopoietic stem cell transplantation (HSTC) because an aberrant expression of these alleles could lead to transplantation-related complications. HLA-DQB1*03:01:01:21Q shows a substitution at the donor splice site of intron 3 that potentially could affect the expression of this allele. In order to determine their expression profile at RNA and protein level, we analyzed the presence of the HLA-DQ7 molecule by complement-dependent cytotoxicity test (CDC) and flow cytometry, and their RNA processing by cDNA analyses and sequencing by Sanger methods. Our results reveal that HLA-DQ7 is not detectable by serological methods, this is confirmed by cDNA methods demonstrating the absence of specific HLA-DQB1*03:01:01:21Q mRNA, probably due to an intron 3 retention that creates a premature TGA stop codon, leading to mRNA degradation via nonsense-mediated decay (NMD). These findings demonstrate that the HLA-DQB1*03:01:01:21Q allele is nonexpressed, thus it has been renamed as DQB1*03:01:01:21N.
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Affiliation(s)
- Luis Alberto Marin Rubio
- Immunology Unit, Clinical Analysis Department, Albacete University Hospital Complex, Albacete, Spain
| | - Jose Daniel Aroca-Aguilar
- Área de Genética, Facultad de Medicina de Albacete/Instituto de Investigación en Discapacidades Neurológicas (IDINE), Universidad de Castilla-La Mancha, Albacete, Spain
| | - Mar Luis-Hidalgo
- Histocompatibilidad, Centro de Transfusión de la Comunidad Valenciana, Valencia, Spain
| | - Julio Escribano
- Área de Genética, Facultad de Medicina de Albacete/Instituto de Investigación en Discapacidades Neurológicas (IDINE), Universidad de Castilla-La Mancha, Albacete, Spain
| | - Jesus Ontañon
- Immunology Unit, Clinical Analysis Department, Albacete University Hospital Complex, Albacete, Spain
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12
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Goldberg Y, Laitman Y, Ben David M, Bazak L, Lidzbarsky G, Salmon LB, Shkedi-Rafid S, Barshack I, Avivi C, Darawshe M, Shomron N, Bruchim R, Vinkler C, Yannoukakos D, Fostira F, Bernstein-Molho R, Friedman E. Re-evaluating the pathogenicity of the c.783+2T>C BAP1 germline variant. Hum Mutat 2021; 42:592-599. [PMID: 33600035 DOI: 10.1002/humu.24189] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 02/09/2021] [Accepted: 02/15/2021] [Indexed: 12/13/2022]
Abstract
BAP1 germline pathogenic sequence variants (PSVs) underlie a unique tumor predisposition syndrome (BAP1-TPDS) associated with an increased lifetime risk for developing primarily pleural and peritoneal mesothelioma and uveal and cutaneous melanoma. Overwhelmingly, BAP1 PSVs are unique, family-specific inactivating variants. We identified seven families, six of Jewish Iraqi origin, harboring an identical BAP1 splice variant (c.783+2T>C), currently assigned a "likely pathogenic" status. Given a nonclassical BAP1-TPDS tumor type clustering and low penetrance in these families, the pathogenicity of this variant was re-evaluated by a combined approach including literature analysis, revised bioinformatics analysis, allelic loss, effect on the transcript, and tumor protein expression patterns. None of the three available tumors showed an allelic loss, there was no discernable effect on alternative splicing based on reverse-transcription polymerase chain reaction, and there was no decrease or loss of somatic protein expression in 2/3 analyzed tumors. This led to assigning a Benign Strong (BS) criteria, BS4, supporting BS3 criteria, and weakening the Pathogenic Supporting (PP) criteria PP5. Combined, these data suggest that this sequence variant should be reclassified as a variant of unknown significance by American College of Medical Genetics (ACMG) criteria.
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Affiliation(s)
- Yael Goldberg
- The Raphael Recanati Genetic Institute, Rabin Medical Center, Beilinson Hospital, Petach Tikva, Israel.,Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Yael Laitman
- Susanne Levy Gertner Oncogenetics Unit, Chaim Sheba Medical Center, Tel-Hashomer, Israel
| | - Merav Ben David
- Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel.,Radiation Oncology Unit, Assuta Medical Center, Tel-Aviv, Israel
| | - Lily Bazak
- The Raphael Recanati Genetic Institute, Rabin Medical Center, Beilinson Hospital, Petach Tikva, Israel
| | - Gabriel Lidzbarsky
- The Raphael Recanati Genetic Institute, Rabin Medical Center, Beilinson Hospital, Petach Tikva, Israel
| | - Lina B Salmon
- The Raphael Recanati Genetic Institute, Rabin Medical Center, Beilinson Hospital, Petach Tikva, Israel.,Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Shiri Shkedi-Rafid
- Department of Genetics, Hadassah-Hebrew University Hospital, Jerusalem, Israel.,Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Iris Barshack
- Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel.,Pathology Institute, Chaim Sheba Medical Center, Tel-Hashomer, Israel
| | - Camila Avivi
- Pathology Institute, Chaim Sheba Medical Center, Tel-Hashomer, Israel
| | - Malak Darawshe
- Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Noam Shomron
- Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Revital Bruchim
- Naot Clinic, Maccabi Health Care Organization, Tel-Aviv, Israel
| | - Chana Vinkler
- Onco Genetis Unit, Institute of Medical Genetics, Wolfson Medical Center, Holon, Israel
| | - Drakoulis Yannoukakos
- Molecular Diagnostics Laboratory, INRASTES, National Centre for Scientific Research "Demokritos", Athens, Greece
| | - Florentia Fostira
- Molecular Diagnostics Laboratory, INRASTES, National Centre for Scientific Research "Demokritos", Athens, Greece
| | - Rinat Bernstein-Molho
- Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel.,Breast Cancer Unit, Institute of Oncology, Chaim Sheba Medical Center, Tel-Hashomer, Israel
| | - Eitan Friedman
- Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel.,Susanne Levy Gertner Oncogenetics Unit, Chaim Sheba Medical Center, Tel-Hashomer, Israel
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13
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Le Tertre M, Ka C, Raud L, Berlivet I, Gourlaouen I, Richard G, Uguen K, Chen JM, Férec C, Fichou Y, Le Gac G. Splicing analysis of SLC40A1 missense variations and contribution to hemochromatosis type 4 phenotypes. Blood Cells Mol Dis 2020; 87:102527. [PMID: 33341511 DOI: 10.1016/j.bcmd.2020.102527] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 11/24/2020] [Accepted: 11/24/2020] [Indexed: 02/09/2023]
Abstract
Hemochromatosis type 4, or ferroportin disease, is considered as the second leading cause of primary iron overload after HFE-related hemochromatosis. The disease, which is predominantly associated with missense variations in the SLC40A1 gene, is characterized by wide clinical heterogeneity. We tested the possibility that some of the reported missense mutations, despite their positions within exons, cause splicing defects. Fifty-eight genetic variants were selected from the literature based on two criteria: a precise description of the nucleotide change and individual evidence of iron overload. The selected variants were investigated by different in silico prediction tools and prioritized for midigene splicing assays. Of the 15 variations tested in vitro, only two were associated with splicing changes. We confirm that the c.1402G>A transition (p.Gly468Ser) disrupts the exon 7 donor site, leading to the use of an exonic cryptic splicing site and the generation of a truncated reading frame. We observed, for the first time, that the p.Gly468Ser substitution has no effect on the ferroportin iron export function. We demonstrate alternative splicing of exon 5 in different cell lines and show that the c.430A>G (p.Asn144Asp) variant promotes exon 5 inclusion. This could be part of a gain-of-function mechanism. We conclude that splicing mutations rarely contribute to hemochromatosis type 4 phenotypes. An in-depth investigation of exon 5 auxiliary splicing sequences may help to elucidate the mechanism by which splicing regulatory proteins regulate the production of the full length SLC40A1 transcript and to clarify its physiological importance.
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Affiliation(s)
- Marlène Le Tertre
- Univ Brest, Inserm, EFS, UMR1078, GGB, F-29200, France; CHRU de Brest, Service de Génétique Médicale et Biologie de la Reproduction, Laboratoire de Génétique Moléculaire et Histocompatibilité, F-29200, France
| | - Chandran Ka
- Univ Brest, Inserm, EFS, UMR1078, GGB, F-29200, France; CHRU de Brest, Service de Génétique Médicale et Biologie de la Reproduction, Laboratoire de Génétique Moléculaire et Histocompatibilité, F-29200, France; Laboratory of Excellence GR-Ex, F-75015, France
| | - Loann Raud
- Univ Brest, Inserm, EFS, UMR1078, GGB, F-29200, France; Association Gaétan Saleün, F-29200, France
| | | | - Isabelle Gourlaouen
- Univ Brest, Inserm, EFS, UMR1078, GGB, F-29200, France; Laboratory of Excellence GR-Ex, F-75015, France
| | | | - Kévin Uguen
- Univ Brest, Inserm, EFS, UMR1078, GGB, F-29200, France; CHRU de Brest, Service de Génétique Médicale et Biologie de la Reproduction, Laboratoire de Génétique Moléculaire et Histocompatibilité, F-29200, France
| | - Jian-Min Chen
- Univ Brest, Inserm, EFS, UMR1078, GGB, F-29200, France
| | - Claude Férec
- Univ Brest, Inserm, EFS, UMR1078, GGB, F-29200, France; CHRU de Brest, Service de Génétique Médicale et Biologie de la Reproduction, Laboratoire de Génétique Moléculaire et Histocompatibilité, F-29200, France; Association Gaétan Saleün, F-29200, France
| | - Yann Fichou
- Univ Brest, Inserm, EFS, UMR1078, GGB, F-29200, France; Laboratory of Excellence GR-Ex, F-75015, France
| | - Gérald Le Gac
- Univ Brest, Inserm, EFS, UMR1078, GGB, F-29200, France; CHRU de Brest, Service de Génétique Médicale et Biologie de la Reproduction, Laboratoire de Génétique Moléculaire et Histocompatibilité, F-29200, France; Laboratory of Excellence GR-Ex, F-75015, France.
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14
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Fukushima S, Farea M, Maeta K, Rani AQM, Fujioka K, Nishio H, Matsuo M. Dual Fluorescence Splicing Reporter Minigene Identifies an Antisense Oligonucleotide to Skip Exon v8 of the CD44 Gene. Int J Mol Sci 2020; 21:9136. [PMID: 33266296 PMCID: PMC7729581 DOI: 10.3390/ijms21239136] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 11/25/2020] [Accepted: 11/29/2020] [Indexed: 12/14/2022] Open
Abstract
Splicing reporter minigenes are used in cell-based in vitro splicing studies. Exon skippable antisense oligonucleotide (ASO) has been identified using minigene splicing assays, but these assays include a time- and cost-consuming step of reverse transcription PCR amplification. To make in vitro splicing assay easier, a ready-made minigene (FMv2) amenable to quantitative splicing analysis by fluorescence microscopy was constructed. FMv2 was designed to encode two fluorescence proteins namely, mCherry, a transfection marker and split eGFP, a marker of splicing reaction. The split eGFP was intervened by an artificial intron containing a multicloning site sequence. Expectedly, FMv2 transfected HeLa cells produced not only red mCherry but also green eGFP signals. Transfection of FMv2CD44v8, a modified clone of FMv2 carrying an insertion of CD44 exon v8 in the multicloning site, that was applied to screen exon v8 skippable ASO, produced only red signals. Among seven different ASOs tested against exon v8, ASO#14 produced the highest index of green signal positive cells. Hence, ASO#14 was the most efficient exon v8 skippable ASO. Notably, the well containing ASO#14 was clearly identified among the 96 wells containing randomly added ASOs, enabling high throughput screening. A ready-made FMv2 is expected to contribute to identify exon skippable ASOs.
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Affiliation(s)
- Sachiyo Fukushima
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan; (S.F.); (K.F.)
- Research Center for Locomotion Biology, Kobe Gakuin University, Kobe 651-2180, Japan; (M.F.); (K.M.); (A.Q.M.R.); (H.N.)
| | - Manal Farea
- Research Center for Locomotion Biology, Kobe Gakuin University, Kobe 651-2180, Japan; (M.F.); (K.M.); (A.Q.M.R.); (H.N.)
| | - Kazuhiro Maeta
- Research Center for Locomotion Biology, Kobe Gakuin University, Kobe 651-2180, Japan; (M.F.); (K.M.); (A.Q.M.R.); (H.N.)
- KNC Department of Nucleic Acid Drug Discovery, Faculty of Rehabilitation, Kobe Gakuin University, Kobe 651-2180, Japan
| | - Abdul Qawee Mahyoob Rani
- Research Center for Locomotion Biology, Kobe Gakuin University, Kobe 651-2180, Japan; (M.F.); (K.M.); (A.Q.M.R.); (H.N.)
- KNC Department of Nucleic Acid Drug Discovery, Faculty of Rehabilitation, Kobe Gakuin University, Kobe 651-2180, Japan
| | - Kazumichi Fujioka
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan; (S.F.); (K.F.)
| | - Hisahide Nishio
- Research Center for Locomotion Biology, Kobe Gakuin University, Kobe 651-2180, Japan; (M.F.); (K.M.); (A.Q.M.R.); (H.N.)
- Department of Occupational Therapy, Faculty of Rehabilitation, Kobe Gakuin University, Kobe 651-2180, Japan
| | - Masafumi Matsuo
- Research Center for Locomotion Biology, Kobe Gakuin University, Kobe 651-2180, Japan; (M.F.); (K.M.); (A.Q.M.R.); (H.N.)
- KNC Department of Nucleic Acid Drug Discovery, Faculty of Rehabilitation, Kobe Gakuin University, Kobe 651-2180, Japan
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15
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Cheng X, Li X, Gu Y, Zhou L, Tang J, Dai X, Jiang H, Huang Y, Zhang Y, Xu T, Liu Z, Zhao Q. Comprehensive Analysis of Alternative Splicing Signature in Gastric Cancer Prognosis Based on The Cancer Genome Atlas (TCGA) and SpliceSeq Databases. Med Sci Monit 2020; 26:e925772. [PMID: 33219199 PMCID: PMC7687027 DOI: 10.12659/msm.925772] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Increasing evidence suggests that the alternative splicing (AS) signature plays a role in the carcinogenesis and prognosis of various cancers. However, the prognostic role of AS in gastric cancer is not clear and needs to be clarified. MATERIAL AND METHODS To identify the differentially expressed AS (DEAS) events, we performed a differential expression analysis between normal and tumor tissue. The DEAS event was further applied to construct a prognostic signature by performing univariate Cox regression analysis and least absolute shrinkage and selection operator (LASSO) analysis. The Kaplan-Meier curve analysis and receiver operating characteristic curve (ROC) analysis were used to evaluate the prognostic value of the AS signature. In addition, the network of the splicing events with splicing factors was constructed using the Cytoscape software. RESULTS A total of 30 005 alternative splicing (AS) events with 372 patients were retrieved from the SpliceSeq database and TCGA database. By performing differential expression analysis, a total of 419 alternative splicing events were screened out, including 56 upregulated and 363 downregulated. We further constructed an AS-related prognostic signature by conducting a series bioinformatics analyses. Moreover, we identified that the AS signature could serve as an independent predictor for the prognosis of GC. We also found that AS signature had a more robust and precise efficacy for prognostic prediction in GC patients. Interestingly, the areas under 3- and 5-year survival curves are similar, both of which are greater than 1-year survival curve, suggesting that the long-term predictive accuracy of our prognostic model built upon AS signature is superior. CONCLUSIONS We performed a comprehensive analysis of overall prognostic-associated AS events concerning GC and constructed a prognostic model to predict the long-term prognostic survival outcomes in GC patients. We also developed a network of splicing events with splicing factors to reveal new potential molecular diagnostic biomarkers and therapeutic targets for GC patients.
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Affiliation(s)
- Xiaohu Cheng
- Department of General Surgery, The Second Hospital of Anhui Medical University, Hefei, Anhui, China (mainland)
| | - Xianghua Li
- Guangzhou Da'an Clinical Test Center Co., Ltd, Guangzhou, Guangdong, China (mainland)
| | - Yimei Gu
- Emergency Intensive Care Unit, First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China (mainland)
| | - Lianbang Zhou
- Department of General Surgery, The Second Hospital of Anhui Medical University, Hefei, Anhui, China (mainland)
| | - Jingjing Tang
- Department of General Surgery, The Second Hospital of Anhui Medical University, Hefei, Anhui, China (mainland)
| | - Xiang Dai
- Department of General Surgery, The Second Hospital of Anhui Medical University, Hefei, Anhui, China (mainland)
| | - Heng Jiang
- Department of General Surgery, The Second Hospital of Anhui Medical University, Hefei, Anhui, China (mainland)
| | - Yang Huang
- Department of General Surgery, The Second Hospital of Anhui Medical University, Hefei, Anhui, China (mainland)
| | - Yingfeng Zhang
- Department of General Surgery, The Second Hospital of Anhui Medical University, Hefei, Anhui, China (mainland)
| | - Tongtong Xu
- Department of General Surgery, The Second Hospital of Anhui Medical University, Hefei, Anhui, China (mainland)
| | - Zhining Liu
- Department of General Surgery, The Second Hospital of Anhui Medical University, Hefei, Anhui, China (mainland)
| | - Qihong Zhao
- School of Public Health, Anhui Medical University, Hefei, Anhui, China (mainland)
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16
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Domingo D, Nawaz U, Corbett M, Espinoza JL, Tatton-Brown K, Coman D, Wilkinson MF, Gecz J, Jolly LA. A synonymous UPF3B variant causing a speech disorder implicates NMD as a regulator of neurodevelopmental disorder gene networks. Hum Mol Genet 2020; 29:2568-2578. [PMID: 32667670 PMCID: PMC10893962 DOI: 10.1093/hmg/ddaa151] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 06/22/2020] [Accepted: 07/11/2020] [Indexed: 11/12/2022] Open
Abstract
Loss-of-function mutations of the X-chromosome gene UPF3B cause male neurodevelopmental disorders (NDDs) via largely unknown mechanisms. We investigated initially by interrogating a novel synonymous UPF3B variant in a male with absent speech. In silico and functional studies using cell lines derived from this individual show altered UPF3B RNA splicing. The resulting mRNA species encodes a frame-shifted protein with a premature termination codon (PTC) predicted to elicit degradation via nonsense-mediated mRNA decay (NMD). UPF3B mRNA was reduced in the cell line, and no UPF3B protein was produced, confirming a loss-of-function allele. UPF3B is itself involved in the NMD mechanism which degrades both PTC-bearing mutant transcripts and also many physiological transcripts. RNAseq analysis showed that ~1.6% of mRNAs exhibited altered expression. These mRNA changes overlapped and correlated with those we identified in additional cell lines obtained from individuals harbouring other UPF3B mutations, permitting us to interrogate pathogenic mechanisms of UPF3B-associated NDDs. We identified 102 genes consistently deregulated across all UPF3B mutant cell lines. Of the 51 upregulated genes, 75% contained an NMD-targeting feature, thus identifying high-confidence direct NMD targets. Intriguingly, 22 of the dysregulated genes encoded known NDD genes, suggesting UPF3B-dependent NMD regulates gene networks critical for cognition and behaviour. Indeed, we show that 78.5% of all NDD genes encode a transcript predicted to be targeted by NMD. These data describe the first synonymous UPF3B mutation in a patient with prominent speech and language disabilities and identify plausible mechanisms of pathology downstream of UPF3B mutations involving the deregulation of NDD-gene networks.
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Affiliation(s)
- Deepti Domingo
- University of Adelaide and Robinson Research Institute, Adelaide, SA 5005, Australia
| | - Urwah Nawaz
- University of Adelaide and Robinson Research Institute, Adelaide, SA 5005, Australia
| | - Mark Corbett
- University of Adelaide and Robinson Research Institute, Adelaide, SA 5005, Australia
| | | | - Katrina Tatton-Brown
- St George’s University of London, London SW17, UK
- Southwest Thames Regional Genetics Centre, St George’s Healthcare NHS Trust, London SW17, UK
| | - David Coman
- School of Medicine, University of Queensland, Brisbane, QLD 4072, Australia
| | - Miles F Wilkinson
- Department of Reproductive Medicine, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
- Institute of Genomic Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Jozef Gecz
- University of Adelaide and Robinson Research Institute, Adelaide, SA 5005, Australia
- South Australian Health and Medical Research Institute, Adelaide, SA 5000, Australia
| | - Lachlan A Jolly
- University of Adelaide and Robinson Research Institute, Adelaide, SA 5005, Australia
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17
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Pathogenic deep intronic MTM1 variant activates a pseudo-exon encoding a nonsense codon resulting in severe X-linked myotubular myopathy. Eur J Hum Genet 2020; 29:61-66. [PMID: 32862205 DOI: 10.1038/s41431-020-00715-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 06/30/2020] [Accepted: 08/21/2020] [Indexed: 12/25/2022] Open
Abstract
X-linked myotubular myopathy (XLMTM) is a severe congenital myopathy characterised by generalised weakness and respiratory insufficiency. XLMTM is associated with pathogenic variants in MTM1; a gene encoding the lipid phosphatase myotubularin. Whole genome sequencing (WGS) of an exome-negative male proband with severe hypotonia, respiratory insufficiency and centralised nuclei on muscle biopsy identified a deep intronic MTM1 variant NG_008199.1(NM_000252.2):c.1468-577A>G, which strengthened a cryptic 5' splice site (A>G substitution at the +5 position). Muscle RNA sequencing was non-diagnostic due to low read depth. Reverse transcription PCR (RT-PCR) of muscle RNA confirmed the c.1468-577A>G variant activates inclusion of a pseudo-exon encoding a premature stop codon into all detected MTM1 transcripts. Western blot analysis establishes deficiency of myotubularin protein, consistent with the severe XLMTM phenotype. We expand the genotypic spectrum of XLMTM and highlight benefits of screening non-coding regions of MTM1 in male probands with phenotypically concordant XLMTM who remain undiagnosed following exome sequencing.
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18
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Maddirevula S, Kuwahara H, Ewida N, Shamseldin HE, Patel N, Alzahrani F, AlSheddi T, AlObeid E, Alenazi M, Alsaif HS, Alqahtani M, AlAli M, Al Ali H, Helaby R, Ibrahim N, Abdulwahab F, Hashem M, Hanna N, Monies D, Derar N, Alsagheir A, Alhashem A, Alsaleem B, Alhebbi H, Wali S, Umarov R, Gao X, Alkuraya FS. Analysis of transcript-deleterious variants in Mendelian disorders: implications for RNA-based diagnostics. Genome Biol 2020; 21:145. [PMID: 32552793 PMCID: PMC7298854 DOI: 10.1186/s13059-020-02053-9] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 05/21/2020] [Indexed: 12/20/2022] Open
Abstract
Background At least 50% of patients with suspected Mendelian disorders remain undiagnosed after whole-exome sequencing (WES), and the extent to which non-coding variants that are not captured by WES contribute to this fraction is unclear. Whole transcriptome sequencing is a promising supplement to WES, although empirical data on the contribution of RNA analysis to the diagnosis of Mendelian diseases on a large scale are scarce. Results Here, we describe our experience with transcript-deleterious variants (TDVs) based on a cohort of 5647 families with suspected Mendelian diseases. We first interrogate all families for which the respective Mendelian phenotype could be mapped to a single locus to obtain an unbiased estimate of the contribution of TDVs at 18.9%. We examine the entire cohort and find that TDVs account for 15% of all “solved” cases. We compare the results of RT-PCR to in silico prediction. Definitive results from RT-PCR are obtained from blood-derived RNA for the overwhelming majority of variants (84.1%), and only a small minority (2.6%) fail analysis on all available RNA sources (blood-, skin fibroblast-, and urine renal epithelial cells-derived), which has important implications for the clinical application of RNA-seq. We also show that RNA analysis can establish the diagnosis in 13.5% of 155 patients who had received “negative” clinical WES reports. Finally, our data suggest a role for TDVs in modulating penetrance even in otherwise highly penetrant Mendelian disorders. Conclusions Our results provide much needed empirical data for the impending implementation of diagnostic RNA-seq in conjunction with genome sequencing.
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Affiliation(s)
- Sateesh Maddirevula
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Hiroyuki Kuwahara
- Computational Bioscience Research Center (CBRC), Computer, Electrical, and Mathematical Sciences and Engineering (CEMSE) Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Nour Ewida
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Hanan E Shamseldin
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Nisha Patel
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Fatema Alzahrani
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Tarfa AlSheddi
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Eman AlObeid
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Mona Alenazi
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Hessa S Alsaif
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Maha Alqahtani
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Maha AlAli
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Hatoon Al Ali
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Rana Helaby
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Niema Ibrahim
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Firdous Abdulwahab
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Mais Hashem
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Nadine Hanna
- Département de génétique, AP-HP, Hôpital Bichat, Université de Paris, LVTS INSERM U1148, Paris, France
| | - Dorota Monies
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Nada Derar
- Deparmtent of Medical Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Afaf Alsagheir
- Department of Pediatrics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Amal Alhashem
- Department of Pediatrics, Prince Sultan Military Medical City, Riyadh, Saudi Arabia.,Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Badr Alsaleem
- Division of Pediatric Gastroenterology, Children's Hospital, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Hamoud Alhebbi
- Department of Pediatrics, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | - Sami Wali
- Department of Pediatrics, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | - Ramzan Umarov
- Computational Bioscience Research Center (CBRC), Computer, Electrical, and Mathematical Sciences and Engineering (CEMSE) Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Xin Gao
- Computational Bioscience Research Center (CBRC), Computer, Electrical, and Mathematical Sciences and Engineering (CEMSE) Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia.
| | - Fowzan S Alkuraya
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia. .,Department of Pediatrics, Prince Sultan Military Medical City, Riyadh, Saudi Arabia. .,Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia.
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19
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Rational Design of an Activatable Reporter for Quantitative Imaging of RNA Aberrant Splicing In Vivo. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2020; 17:904-911. [PMID: 32405512 PMCID: PMC7210378 DOI: 10.1016/j.omtm.2020.04.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 04/13/2020] [Indexed: 02/02/2023]
Abstract
Pre-mRNA splicing, the process of removing introns from pre-mRNA and the arrangement of exons to produce mature transcripts, is a crucial step in the expression of most eukaryote genes. However, the splicing kinetics remain poorly characterized in living cells, mainly because current methods cannot provide the dynamic information of splicing events. Here, we developed a genetically encoded bioluminescence reporter for real-time imaging of the pre-mRNA splicing process in living subjects. We showed that the bioluminescence reporter is able to visualize the pre-mRNA aberrant splicing process in living cells in a dose- and time-dependent manner. Moreover, this reporter could provide quantitative and longitudinal information of splicing activity in response to exogenous splicing inhibitors in living animals. Our data suggest that this activatable reporter could serve as a promising tool for the high-throughput screening of splicing modulators, which would facilitate the drug development for human diseases caused by the abnormal splicing of mRNA.
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20
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Abstract
Next generation DNA sequencing (NGS) has the potential to improve the diagnostic and prognostic utility of newborn screening programmes. This study assesses the feasibility of automating NGS on dried blood spot (DBS) DNA in a United Kingdom National Health Service (UK NHS) laboratory. An NGS panel targeting the entire coding sequence of five genes relevant to disorders currently screened for in newborns in the UK was validated on DBS DNA. An automated process for DNA extraction, NGS and bioinformatics analysis was developed. The process was tested on DBS to determine feasibility, turnaround time and cost. The analytical sensitivity of the assay was 100% and analytical specificity was 99.96%, with a mean 99.5% concordance of variant calls between DBS and venous blood samples in regions with ≥30× coverage (96.8% across all regions; all variant calls were single nucleotide variants (SNVs), with indel performance not assessed). The pipeline enabled processing of up to 1000 samples a week with a turnaround time of four days from receipt of sample to reporting. This study concluded that it is feasible to automate targeted NGS on routine DBS samples in a UK NHS laboratory setting, but it may not currently be cost effective as a first line test.
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21
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Marco-Puche G, Lois S, Benítez J, Trivino JC. RNA-Seq Perspectives to Improve Clinical Diagnosis. Front Genet 2019; 10:1152. [PMID: 31781178 PMCID: PMC6861419 DOI: 10.3389/fgene.2019.01152] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 10/22/2019] [Indexed: 01/22/2023] Open
Abstract
In recent years, high-throughput next-generation sequencing technology has allowed a rapid increase in diagnostic capacity and precision through different bioinformatics processing algorithms, tools, and pipelines. The identification, annotation, and classification of sequence variants within different target regions are now considered a gold standard in clinical genetic diagnosis. However, this procedure lacks the ability to link regulatory events such as differential splicing to diseases. RNA-seq is necessary in clinical routine in order to interpret and detect among others splicing events and splicing variants, as it would increase the diagnostic rate by up to 10-35%. The transcriptome has a very dynamic nature, varying according to tissue type, cellular conditions, and environmental factors that may affect regulatory events such as splicing and the expression of genes or their isoforms. RNA-seq offers a robust technical analysis of this complexity, but it requires a profound knowledge of computational/statistical tools that may need to be adjusted depending on the disease under study. In this article we will cover RNA-seq analyses best practices applied to clinical routine, bioinformatics procedures, and present challenges of this approach.
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Affiliation(s)
| | - Sergio Lois
- Bioinformatics Group, Sistemas Genómicos, Paterna, Spain
| | - Javier Benítez
- Human Genetics Group, Spanish National Cancer Research Center, Madrid, Spain
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22
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Hecker M, Rüge A, Putscher E, Boxberger N, Rommer PS, Fitzner B, Zettl UK. Aberrant expression of alternative splicing variants in multiple sclerosis - A systematic review. Autoimmun Rev 2019; 18:721-732. [PMID: 31059848 DOI: 10.1016/j.autrev.2019.05.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2019] [Accepted: 02/22/2019] [Indexed: 02/07/2023]
Abstract
OBJECTIVE Alternative splicing is an important form of RNA processing that affects nearly all human genes. The differential expression of specific transcript and protein isoforms holds the potential of novel biomarkers for complex diseases. In this systematic review, we compiled the existing literature on aberrant alternative splicing events in multiple sclerosis (MS). METHODS A systematic literature search in the PubMed database was carried out and supplemented by screening the reference lists of the identified articles. We selected only MS-related original research studies which compared the levels of different isoforms of human protein-coding genes. A narrative synthesis of the research findings was conducted. Additionally, we performed a case-control analysis using high-density transcriptome microarray data to reevaluate the genes that were examined in the reviewed studies. RESULTS A total of 160 records were screened. Of those, 36 studies from the last two decades were included. Most commonly, peripheral blood samples were analyzed (32 studies), and PCR-based techniques were usually employed (27 studies) for measuring the expression of selected genes. Two studies used an exploratory genome-wide approach. Overall, 27 alternatively spliced genes were investigated. Nine of these genes appeared in at least two studies (CD40, CFLAR, FOXP3, IFNAR2, IL7R, MOG, PTPRC, SP140 and TNFRSF1A). The microarray data analysis confirmed differential alternative pre-mRNA splicing for 19 genes. CONCLUSIONS An altered RNA processing of genes mediating immune signaling pathways has been repeatedly implicated in MS. The analysis of individual exon-level expression patterns is stimulated by the advancement of transcriptome profiling technologies. In particular, the examination of genes encoded in MS-associated genetic regions may provide important insights into the pathogenesis of the disease and help to identify new biomarkers.
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Affiliation(s)
- Michael Hecker
- University of Rostock, Department of Neurology, Division of Neuroimmunology, Gehlsheimer Str. 20, 18147 Rostock, Germany.
| | - Annelen Rüge
- University of Rostock, Department of Neurology, Division of Neuroimmunology, Gehlsheimer Str. 20, 18147 Rostock, Germany
| | - Elena Putscher
- University of Rostock, Department of Neurology, Division of Neuroimmunology, Gehlsheimer Str. 20, 18147 Rostock, Germany
| | - Nina Boxberger
- University of Rostock, Department of Neurology, Division of Neuroimmunology, Gehlsheimer Str. 20, 18147 Rostock, Germany
| | - Paulus Stefan Rommer
- University of Rostock, Department of Neurology, Division of Neuroimmunology, Gehlsheimer Str. 20, 18147 Rostock, Germany; Medical University of Vienna, Department of Neurology, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Brit Fitzner
- University of Rostock, Department of Neurology, Division of Neuroimmunology, Gehlsheimer Str. 20, 18147 Rostock, Germany
| | - Uwe Klaus Zettl
- University of Rostock, Department of Neurology, Division of Neuroimmunology, Gehlsheimer Str. 20, 18147 Rostock, Germany
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