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Gezdirici A, Kalaycik Şengül Ö, Doğan M, Özgüven BY, Akbulut E. Biallelic Novel USP53 Splicing Variant Disrupting the Gene Function that Causes Cholestasis Phenotype and Review of the Literature. Mol Syndromol 2023; 13:471-484. [PMID: 36660033 PMCID: PMC9843568 DOI: 10.1159/000523937] [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: 08/11/2021] [Accepted: 03/02/2022] [Indexed: 01/22/2023] Open
Abstract
Introduction Hereditary cholestasis is a heterogeneous group of liver diseases that mostly show autosomal recessive inheritance. The phenotype of cholestasis is highly variable. Molecular genetic testing offers an useful approach to differentiate different types of cholestasis because some symptoms and findings overlap. Biallelic variants in USP53 have recently been reported in cholestasis phenotype. Methods In this study, we aimed to characterize clinical findings and biological insights on a novel USP53 splice variant causing cholestasis phenotype and provided a review of the literature. We performed whole-exome sequencing and then confirmed it with Sanger sequencing. In addition, as a result of in silico analyses and cDNA analysis, we showed that the USP53 protein in our patient was shortened. Results We report a novel splice variant (NM_019050.2:c.238-1G>C) in the USP53 gene via whole-exome sequencing in a patient with cholestasis phenotype. This variant was confirmed by Sanger sequencing and was a result of family segregation analysis; it was found to be in a heterozygous state in the parents and the other healthy elder brother of our patient. According to in silico analyses, the change in the splice region resulted in an increase in the length of exon 2, whereas the stop codon after the additional 3 amino acids (VTF) caused the protein to terminate prematurely. Thus, the mature USP53 protein, consisting of 1,073 amino acids, has been reduced to a small protein of 82 amino acids. Conclusion We propose a model for the tertiary structure of USP53 for the first time, and together with all these data, we support the association of biallelic variants of the USP53 gene with cholestasis phenotype. We also present a comparison of previously reported patients with USP53-associated cholestasis phenotype to contribute to the literature.
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Affiliation(s)
- Alper Gezdirici
- Department of Medical Genetics, Basaksehir Cam and Sakura City Hospital, Istanbul, Turkey,*Alper Gezdirici,
| | - Özlem Kalaycik Şengül
- Department of Pediatric Gastroenterology, Hepatology and Nutrition, Kanuni Sultan Suleyman Training and Research Hospital, Istanbul, Turkey
| | - Mustafa Doğan
- Department of Medical Genetics, Basaksehir Cam and Sakura City Hospital, Istanbul, Turkey
| | - Banu Y. Özgüven
- Department of Pathology, Basaksehir Cam and Sakura City Hospital, Istanbul, Turkey
| | - Ekrem Akbulut
- Department of Bioengineering, Malatya Turgut Ozal University, Malatya, Turkey
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2
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Disciglio V, Forte G, Fasano C, Sanese P, Lepore Signorile M, De Marco K, Grossi V, Cariola F, Simone C. APC Splicing Mutations Leading to In-Frame Exon 12 or Exon 13 Skipping Are Rare Events in FAP Pathogenesis and Define the Clinical Outcome. Genes (Basel) 2021; 12:genes12030353. [PMID: 33670833 PMCID: PMC7997234 DOI: 10.3390/genes12030353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 02/22/2021] [Accepted: 02/22/2021] [Indexed: 11/16/2022] Open
Abstract
Familial adenomatous polyposis (FAP) is caused by germline mutations in the tumor suppressor gene APC. To date, nearly 2000 APC mutations have been described in FAP, most of which are predicted to result in truncated protein products. Mutations leading to aberrant APC splicing have rarely been reported. Here, we characterized a novel germline heterozygous splice donor site mutation in APC exon 12 (NM_000038.5: c.1621_1626+7del) leading to exon 12 skipping in an Italian family with the attenuated FAP (AFAP) phenotype. Moreover, we performed a literature meta-analysis of APC splicing mutations. We found that 119 unique APC splicing mutations, including the one described here, have been reported in FAP patients, 69 of which have been characterized at the mRNA level. Among these, only a small proportion (9/69) results in an in-frame protein, with four mutations causing skipping of exon 12 or 13 with loss of armadillo repeat 2 (ARM2) and 3 (ARM3), and five mutations leading to skipping of exon 5, 7, 8, or (partially) 9 with loss of regions not encompassing known functional domains. The APC splicing mutations causing skipping of exon 12 or 13 considered in this study cluster with the AFAP phenotype and reveal a potential molecular mechanism of pathogenesis in FAP disease.
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Affiliation(s)
- Vittoria Disciglio
- Medical Genetics, National Institute of Gastroenterology “S. de Bellis” Research Hospital, Castellana Grotte, 70013 Bari, Italy; (G.F.); (C.F.); (P.S.); (M.L.S.); (K.D.M.); (V.G.); (F.C.)
- Correspondence: (V.D.); (C.S.)
| | - Giovanna Forte
- Medical Genetics, National Institute of Gastroenterology “S. de Bellis” Research Hospital, Castellana Grotte, 70013 Bari, Italy; (G.F.); (C.F.); (P.S.); (M.L.S.); (K.D.M.); (V.G.); (F.C.)
| | - Candida Fasano
- Medical Genetics, National Institute of Gastroenterology “S. de Bellis” Research Hospital, Castellana Grotte, 70013 Bari, Italy; (G.F.); (C.F.); (P.S.); (M.L.S.); (K.D.M.); (V.G.); (F.C.)
| | - Paola Sanese
- Medical Genetics, National Institute of Gastroenterology “S. de Bellis” Research Hospital, Castellana Grotte, 70013 Bari, Italy; (G.F.); (C.F.); (P.S.); (M.L.S.); (K.D.M.); (V.G.); (F.C.)
| | - Martina Lepore Signorile
- Medical Genetics, National Institute of Gastroenterology “S. de Bellis” Research Hospital, Castellana Grotte, 70013 Bari, Italy; (G.F.); (C.F.); (P.S.); (M.L.S.); (K.D.M.); (V.G.); (F.C.)
| | - Katia De Marco
- Medical Genetics, National Institute of Gastroenterology “S. de Bellis” Research Hospital, Castellana Grotte, 70013 Bari, Italy; (G.F.); (C.F.); (P.S.); (M.L.S.); (K.D.M.); (V.G.); (F.C.)
| | - Valentina Grossi
- Medical Genetics, National Institute of Gastroenterology “S. de Bellis” Research Hospital, Castellana Grotte, 70013 Bari, Italy; (G.F.); (C.F.); (P.S.); (M.L.S.); (K.D.M.); (V.G.); (F.C.)
| | - Filomena Cariola
- Medical Genetics, National Institute of Gastroenterology “S. de Bellis” Research Hospital, Castellana Grotte, 70013 Bari, Italy; (G.F.); (C.F.); (P.S.); (M.L.S.); (K.D.M.); (V.G.); (F.C.)
| | - Cristiano Simone
- Medical Genetics, National Institute of Gastroenterology “S. de Bellis” Research Hospital, Castellana Grotte, 70013 Bari, Italy; (G.F.); (C.F.); (P.S.); (M.L.S.); (K.D.M.); (V.G.); (F.C.)
- Department of Biomedical Sciences and Human Oncology (DIMO), Medical Genetics, University of Bari Aldo Moro, 70124 Bari, Italy
- Correspondence: (V.D.); (C.S.)
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3
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Sarkar A, Yang Y, Vihinen M. Variation benchmark datasets: update, criteria, quality and applications. DATABASE-THE JOURNAL OF BIOLOGICAL DATABASES AND CURATION 2020; 2020:5710862. [PMID: 32016318 PMCID: PMC6997940 DOI: 10.1093/database/baz117] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 06/03/2019] [Accepted: 07/01/2019] [Indexed: 02/07/2023]
Abstract
Development of new computational methods and testing their performance has to be carried out using experimental data. Only in comparison to existing knowledge can method performance be assessed. For that purpose, benchmark datasets with known and verified outcome are needed. High-quality benchmark datasets are valuable and may be difficult, laborious and time consuming to generate. VariBench and VariSNP are the two existing databases for sharing variation benchmark datasets used mainly for variation interpretation. They have been used for training and benchmarking predictors for various types of variations and their effects. VariBench was updated with 419 new datasets from 109 papers containing altogether 329 014 152 variants; however, there is plenty of redundancy between the datasets. VariBench is freely available at http://structure.bmc.lu.se/VariBench/. The contents of the datasets vary depending on information in the original source. The available datasets have been categorized into 20 groups and subgroups. There are datasets for insertions and deletions, substitutions in coding and non-coding region, structure mapped, synonymous and benign variants. Effect-specific datasets include DNA regulatory elements, RNA splicing, and protein property for aggregation, binding free energy, disorder and stability. Then there are several datasets for molecule-specific and disease-specific applications, as well as one dataset for variation phenotype effects. Variants are often described at three molecular levels (DNA, RNA and protein) and sometimes also at the protein structural level including relevant cross references and variant descriptions. The updated VariBench facilitates development and testing of new methods and comparison of obtained performances to previously published methods. We compared the performance of the pathogenicity/tolerance predictor PON-P2 to several benchmark studies, and show that such comparisons are feasible and useful, however, there may be limitations due to lack of provided details and shared data. Database URL: http://structure.bmc.lu.se/VariBench
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Affiliation(s)
- Anasua Sarkar
- Department of Experimental Medical Science, BMC B13, Lund University, SE-22 184 Lund, Sweden
| | - Yang Yang
- School of Computer Science and Technology, Soochow University, No1. Shizi Street, Suzhou, 215006 Jiangsu, China.,Provincial Key Laboratory for Computer Information Processing Technology, No1. Shizi Street, Soochow University, Suzhou, 215006 Jiangsu, China
| | - Mauno Vihinen
- Department of Experimental Medical Science, BMC B13, Lund University, SE-22 184 Lund, Sweden
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4
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Rogan PK, Mucaki EJ, Shirley BC. A proposed molecular mechanism for pathogenesis of severe RNA-viral pulmonary infections. F1000Res 2020; 9:943. [PMID: 33299552 PMCID: PMC7676395 DOI: 10.12688/f1000research.25390.1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/23/2020] [Indexed: 12/19/2022] Open
Abstract
Background: Certain riboviruses can cause severe pulmonary complications leading to death in some infected patients. We propose that DNA damage induced-apoptosis accelerates viral release, triggered by depletion of host RNA binding proteins (RBPs) from nuclear RNA bound to replicating viral sequences. Methods: Information theory-based analysis of interactions between RBPs and individual sequences in the Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2), Influenza A (H3N1), HIV-1, and Dengue genomes identifies strong RBP binding sites in these viral genomes. Replication and expression of viral sequences is expected to increasingly sequester RBPs - SRSF1 and RNPS1. Ordinarily, RBPs bound to nascent host transcripts prevents their annealing to complementary DNA. Their depletion induces destabilizing R-loops. Chromosomal breakage occurs when an excess of unresolved R-loops collide with incoming replication forks, overwhelming the DNA repair machinery. We estimated stoichiometry of inhibition of RBPs in host nuclear RNA by counting competing binding sites in replicating viral genomes and host RNA. Results: Host RBP binding sites are frequent and conserved among different strains of RNA viral genomes. Similar binding motifs of SRSF1 and RNPS1 explain why DNA damage resulting from SRSF1 depletion is complemented by expression of RNPS1. Clustering of strong RBP binding sites coincides with the distribution of RNA-DNA hybridization sites across the genome. SARS-CoV-2 replication is estimated to require 32.5-41.8 hours to effectively compete for binding of an equal proportion of SRSF1 binding sites in host encoded nuclear RNAs. Significant changes in expression of transcripts encoding DNA repair and apoptotic proteins were found in an analysis of influenza A and Dengue-infected cells in some individuals. Conclusions: R-loop-induced apoptosis indirectly resulting from viral replication could release significant quantities of membrane-associated virions into neighboring alveoli. These could infect adjacent pneumocytes and other tissues, rapidly compromising lung function, causing multiorgan system failure and other described symptoms.
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Affiliation(s)
- Peter K. Rogan
- Biochemistry, University of Western Ontario, London, Ontario, N6A 2C8, Canada
- CytoGnomix Inc, London, Ontario, N5X 3X5, Canada
| | - Eliseos J. Mucaki
- Biochemistry, University of Western Ontario, London, Ontario, N6A 2C8, Canada
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5
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Rogan PK, Mucaki EJ, Shirley BC. A proposed molecular mechanism for pathogenesis of severe RNA-viral pulmonary infections. F1000Res 2020; 9:943. [PMID: 33299552 PMCID: PMC7676395 DOI: 10.12688/f1000research.25390.2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/16/2020] [Indexed: 12/19/2022] Open
Abstract
Background: Certain riboviruses can cause severe pulmonary complications leading to death in some infected patients. We propose that DNA damage induced-apoptosis accelerates viral release, triggered by depletion of host RNA binding proteins (RBPs) from nuclear RNA bound to replicating viral sequences. Methods: Information theory-based analysis of interactions between RBPs and individual sequences in the Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2), Influenza A (H3N2), HIV-1, and Dengue genomes identifies strong RBP binding sites in these viral genomes. Replication and expression of viral sequences is expected to increasingly sequester RBPs - SRSF1 and RNPS1. Ordinarily, RBPs bound to nascent host transcripts prevents their annealing to complementary DNA. Their depletion induces destabilizing R-loops. Chromosomal breakage occurs when an excess of unresolved R-loops collide with incoming replication forks, overwhelming the DNA repair machinery. We estimated stoichiometry of inhibition of RBPs in host nuclear RNA by counting competing binding sites in replicating viral genomes and host RNA. Results: Host RBP binding sites are frequent and conserved among different strains of RNA viral genomes. Similar binding motifs of SRSF1 and RNPS1 explain why DNA damage resulting from SRSF1 depletion is complemented by expression of RNPS1. Clustering of strong RBP binding sites coincides with the distribution of RNA-DNA hybridization sites across the genome. SARS-CoV-2 replication is estimated to require 32.5-41.8 hours to effectively compete for binding of an equal proportion of SRSF1 binding sites in host encoded nuclear RNAs. Significant changes in expression of transcripts encoding DNA repair and apoptotic proteins were found in an analysis of influenza A and Dengue-infected cells in some individuals. Conclusions: R-loop-induced apoptosis indirectly resulting from viral replication could release significant quantities of membrane-associated virions into neighboring alveoli. These could infect adjacent pneumocytes and other tissues, rapidly compromising lung function, causing multiorgan system failure and other described symptoms.
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Affiliation(s)
- Peter K. Rogan
- Biochemistry, University of Western Ontario, London, Ontario, N6A 2C8, Canada
- CytoGnomix Inc, London, Ontario, N5X 3X5, Canada
| | - Eliseos J. Mucaki
- Biochemistry, University of Western Ontario, London, Ontario, N6A 2C8, Canada
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6
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Corbin LJ, Pope J, Sanson J, Antczak DF, Miller D, Sadeghi R, Brooks SA. An Independent Locus Upstream of ASIP Controls Variation in the Shade of the Bay Coat Colour in Horses. Genes (Basel) 2020; 11:E606. [PMID: 32486210 PMCID: PMC7349280 DOI: 10.3390/genes11060606] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 05/20/2020] [Accepted: 05/27/2020] [Indexed: 01/09/2023] Open
Abstract
Novel coat colour phenotypes often emerge during domestication, and there is strong evidence of genetic selection for the two main genes that control base coat colour in horses-ASIP and MC1R. These genes direct the type of pigment produced, red pheomelanin (MC1R) or black eumelanin (ASIP), as well as the relative concentration and the temporal-spatial distribution of melanin pigment deposits in the skin and hair coat. Here, we describe a genome-wide association study (GWAS) to identify novel genic regions involved in the determination of the shade of bay. In total, 126 horses from five different breeds were ranked according to the extent of the distribution of eumelanin: spanning variation in phenotype from black colour restricted only to the extremities to the presence of some black pigment across nearly all the body surface. We identified a single region associated with the shade of bay ranking spanning approximately 0.5 MB on ECA22, just upstream of the ASIP gene (p = 9.76 × 10-15). This candidate region encompasses the distal 5' end of the ASIP transcript (as predicted from other species) as well as the RALY gene. Both loci are viable candidates based on the presence of similar alleles in other species. These results contribute to the growing understanding of coat colour genetics in the horse and to the mapping of genetic determinants of pigmentation on a molecular level. Given pleiotropic phenotypes in behaviour and obesity for ASIP alleles, especially those in the 5' regulatory region, improved understanding of this new Shade allele may have implications for health management in the horse.
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Affiliation(s)
- Laura J. Corbin
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol BS8 2BN, UK;
- MRC Integrative Epidemiology Unit at University of Bristol, Bristol BS8 2BN, UK
| | - Jessica Pope
- Bristol Veterinary School, University of Bristol, Bristol BS8 1QU, UK;
| | - Jacqueline Sanson
- Department of Animal Sciences, University of Florida, Gainesville, FL 32610, USA;
| | - Douglas F. Antczak
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA; (D.F.A.); (D.M.); (R.S.)
| | - Donald Miller
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA; (D.F.A.); (D.M.); (R.S.)
| | - Raheleh Sadeghi
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA; (D.F.A.); (D.M.); (R.S.)
| | - Samantha A. Brooks
- Department of Animal Sciences, University of Florida, Gainesville, FL 32610, USA;
- UF Genetics Institute, University of Florida, Gainesville, FL 32611, USA
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7
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Mucaki EJ, Shirley BC, Rogan PK. Expression Changes Confirm Genomic Variants Predicted to Result in Allele-Specific, Alternative mRNA Splicing. Front Genet 2020; 11:109. [PMID: 32211018 PMCID: PMC7066660 DOI: 10.3389/fgene.2020.00109] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Accepted: 01/30/2020] [Indexed: 12/11/2022] Open
Abstract
Splice isoform structure and abundance can be affected by either noncoding or masquerading coding variants that alter the structure or abundance of transcripts. When these variants are common in the population, these nonconstitutive transcripts are sufficiently frequent so as to resemble naturally occurring, alternative mRNA splicing. Prediction of the effects of such variants has been shown to be accurate using information theory-based methods. Single nucleotide polymorphisms (SNPs) predicted to significantly alter natural and/or cryptic splice site strength were shown to affect gene expression. Splicing changes for known SNP genotypes were confirmed in HapMap lymphoblastoid cell lines with gene expression microarrays and custom designed q-RT-PCR or TaqMan assays. The majority of these SNPs (15 of 22) as well as an independent set of 24 variants were then subjected to RNAseq analysis using the ValidSpliceMut web beacon (http://validsplicemut.cytognomix.com), which is based on data from the Cancer Genome Atlas and International Cancer Genome Consortium. SNPs from different genes analyzed with gene expression microarray and q-RT-PCR exhibited significant changes in affected splice site use. Thirteen SNPs directly affected exon inclusion and 10 altered cryptic site use. Homozygous SNP genotypes resulting in stronger splice sites exhibited higher levels of processed mRNA than alleles associated with weaker sites. Four SNPs exhibited variable expression among individuals with the same genotypes, masking statistically significant expression differences between alleles. Genome-wide information theory and expression analyses (RNAseq) in tumor exomes and genomes confirmed splicing effects for 7 of the HapMap SNP and 14 SNPs identified from tumor genomes. q-RT-PCR resolved rare splice isoforms with read abundance too low for statistical significance in ValidSpliceMut. Nevertheless, the web-beacon provides evidence of unanticipated splicing outcomes, for example, intron retention due to compromised recognition of constitutive splice sites. Thus, ValidSpliceMut and q-RT-PCR represent complementary resources for identification of allele-specific, alternative splicing.
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Affiliation(s)
- Eliseos J Mucaki
- Department of Biochemistry, University of Western Ontario, London, ON, Canada
| | | | - Peter K Rogan
- Department of Biochemistry, University of Western Ontario, London, ON, Canada.,CytoGnomix, London, ON, Canada.,Department of Oncology University of Western Ontario, London, ON, Canada.,Department of Computer Science, University of Western Ontario, London, ON, Canada
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8
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Shirley BC, Mucaki EJ, Rogan PK. Pan-cancer repository of validated natural and cryptic mRNA splicing mutations. F1000Res 2019; 7:1908. [PMID: 31275557 DOI: 10.12688/f1000research.17204.1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/30/2018] [Indexed: 12/26/2022] Open
Abstract
We present a major public resource of mRNA splicing mutations validated according to multiple lines of evidence of abnormal gene expression. Likely mutations present in all tumor types reported in the Cancer Genome Atlas (TCGA) and the International Cancer Genome Consortium (ICGC) were identified based on the comparative strengths of splice sites in tumor versus normal genomes, and then validated by respectively comparing counts of splice junction spanning and abundance of transcript reads in RNA-Seq data from matched tissues and tumors lacking these mutations. The comprehensive resource features 341,486 of these validated mutations, the majority of which (69.9%) are not present in the Single Nucleotide Polymorphism Database (dbSNP 150). There are 131,347 unique mutations which weaken or abolish natural splice sites, and 222,071 mutations which strengthen cryptic splice sites (11,932 affect both simultaneously). 28,812 novel or rare flagged variants (with <1% population frequency in dbSNP) were observed in multiple tumor tissue types. An algorithm was developed to classify variants into splicing molecular phenotypes that integrates germline heterozygosity, degree of information change and impact on expression. The classification thresholds were calibrated against the ClinVar clinical database phenotypic assignments. Variants are partitioned into allele-specific alternative splicing, likely aberrant and aberrant splicing phenotypes. Single variants or chromosome ranges can be queried using a Global Alliance for Genomics and Health (GA4GH)-compliant, web-based Beacon "Validated Splicing Mutations" either separately or in aggregate alongside other Beacons through the public Beacon Network, as well as through our website. The website provides additional information, such as a visual representation of supporting RNAseq results, gene expression in the corresponding normal tissues, and splicing molecular phenotypes.
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Affiliation(s)
| | - Eliseos J Mucaki
- Biochemistry, University of Western Ontario, London, Ontario, N6A 2C1, Canada
| | - Peter K Rogan
- CytoGnomix Inc., London, Ontario, N5X 3X5, Canada.,Biochemistry, University of Western Ontario, London, Ontario, N6A 2C1, Canada.,Computer Science, University of Western Ontario, London, Ontario, N6A 2C1, Canada.,Oncology, University of Western Ontario, London, Ontario, N6A 2C1, Canada
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9
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Shirley BC, Mucaki EJ, Rogan PK. Pan-cancer repository of validated natural and cryptic mRNA splicing mutations. F1000Res 2018; 7:1908. [PMID: 31275557 PMCID: PMC6544075 DOI: 10.12688/f1000research.17204.3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/27/2019] [Indexed: 11/20/2022] Open
Abstract
We present a major public resource of mRNA splicing mutations validated according to multiple lines of evidence of abnormal gene expression. Likely mutations present in all tumor types reported in the Cancer Genome Atlas (TCGA) and the International Cancer Genome Consortium (ICGC) were identified based on the comparative strengths of splice sites in tumor versus normal genomes, and then validated by respectively comparing counts of splice junction spanning and abundance of transcript reads in RNA-Seq data from matched tissues and tumors lacking these mutations. The comprehensive resource features 341,486 of these validated mutations, the majority of which (69.9%) are not present in the Single Nucleotide Polymorphism Database (dbSNP 150). There are 131,347 unique mutations which weaken or abolish natural splice sites, and 222,071 mutations which strengthen cryptic splice sites (11,932 affect both simultaneously). 28,812 novel or rare flagged variants (with <1% population frequency in dbSNP) were observed in multiple tumor tissue types. An algorithm was developed to classify variants into splicing molecular phenotypes that integrates germline heterozygosity, degree of information change and impact on expression. The classification thresholds were calibrated against the ClinVar clinical database phenotypic assignments. Variants are partitioned into allele-specific alternative splicing, likely aberrant and aberrant splicing phenotypes. Single variants or chromosome ranges can be queried using a Global Alliance for Genomics and Health (GA4GH)-compliant, web-based Beacon "Validated Splicing Mutations" either separately or in aggregate alongside other Beacons through the public Beacon Network, as well as through our website. The website provides additional information, such as a visual representation of supporting RNAseq results, gene expression in the corresponding normal tissues, and splicing molecular phenotypes.
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Affiliation(s)
| | - Eliseos J Mucaki
- Biochemistry, University of Western Ontario, London, Ontario, N6A 2C1, Canada
| | - Peter K Rogan
- CytoGnomix Inc., London, Ontario, N5X 3X5, Canada.,Biochemistry, University of Western Ontario, London, Ontario, N6A 2C1, Canada.,Computer Science, University of Western Ontario, London, Ontario, N6A 2C1, Canada.,Oncology, University of Western Ontario, London, Ontario, N6A 2C1, Canada
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10
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Dron JS, Wang J, Low-Kam C, Khetarpal SA, Robinson JF, McIntyre AD, Ban MR, Cao H, Rhainds D, Dubé MP, Rader DJ, Lettre G, Tardif JC, Hegele RA. Polygenic determinants in extremes of high-density lipoprotein cholesterol. J Lipid Res 2017; 58:2162-2170. [PMID: 28870971 PMCID: PMC5665671 DOI: 10.1194/jlr.m079822] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 08/31/2017] [Indexed: 11/24/2022] Open
Abstract
HDL cholesterol (HDL-C) remains a superior biochemical predictor of CVD risk, but its genetic basis is incompletely defined. In patients with extreme HDL-C concentrations, we concurrently evaluated the contributions of multiple large- and small-effect genetic variants. In a discovery cohort of 255 unrelated lipid clinic patients with extreme HDL-C levels, we used a targeted next-generation sequencing panel to evaluate rare variants in known HDL metabolism genes, simultaneously with common variants bundled into a polygenic trait score. Two additional cohorts were used for validation and included 1,746 individuals from the Montréal Heart Institute Biobank and 1,048 individuals from the University of Pennsylvania. Findings were consistent between cohorts: we found rare heterozygous large-effect variants in 18.7% and 10.9% of low- and high-HDL-C patients, respectively. We also found common variant accumulation, indicated by extreme polygenic trait scores, in an additional 12.8% and 19.3% of overall cases of low- and high-HDL-C extremes, respectively. Thus, the genetic basis of extreme HDL-C concentrations encountered clinically is frequently polygenic, with contributions from both rare large-effect and common small-effect variants. Multiple types of genetic variants should be considered as contributing factors in patients with extreme dyslipidemia.
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Affiliation(s)
- Jacqueline S Dron
- Department of Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
- Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Jian Wang
- Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Cécile Low-Kam
- Montréal Heart Institute et Faculté de Médecine, Université de Montréal, Montréal, Québec, Canada
| | - Sumeet A Khetarpal
- Departments of Genetics and Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - John F Robinson
- Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Adam D McIntyre
- Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Matthew R Ban
- Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Henian Cao
- Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - David Rhainds
- Montréal Heart Institute et Faculté de Médecine, Université de Montréal, Montréal, Québec, Canada
| | - Marie-Pierre Dubé
- Montréal Heart Institute et Faculté de Médecine, Université de Montréal, Montréal, Québec, Canada
| | - Daniel J Rader
- Departments of Genetics, Medicine, and Pediatrics, the Cardiovascular Institute, and the Institute for Translational Medicine and Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Guillaume Lettre
- Montréal Heart Institute et Faculté de Médecine, Université de Montréal, Montréal, Québec, Canada
| | - Jean-Claude Tardif
- Montréal Heart Institute et Faculté de Médecine, Université de Montréal, Montréal, Québec, Canada
| | - Robert A Hegele
- Department of Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
- Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
- Department of Medicine, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
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11
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Khetarpal SA, Zeng X, Millar JS, Vitali C, Somasundara AVH, Zanoni P, Landro JA, Barucci N, Zavadoski WJ, Sun Z, de Haard H, Toth IV, Peloso GM, Natarajan P, Cuchel M, Lund-Katz S, Phillips MC, Tall AR, Kathiresan S, DaSilva-Jardine P, Yates NA, Rader DJ. A human APOC3 missense variant and monoclonal antibody accelerate apoC-III clearance and lower triglyceride-rich lipoprotein levels. Nat Med 2017; 23:1086-1094. [PMID: 28825717 PMCID: PMC5669375 DOI: 10.1038/nm.4390] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 07/25/2017] [Indexed: 12/22/2022]
Abstract
Recent large-scale genetic sequencing efforts have identified rare coding variants in genes in the triglyceride-rich lipoprotein (TRL) clearance pathway that are protective against coronary heart disease (CHD), independently of LDL cholesterol (LDL-C) levels. Insight into the mechanisms of protection of these variants may facilitate the development of new therapies for lowering TRL levels. The gene APOC3 encodes apoC-III, a critical inhibitor of triglyceride (TG) lipolysis and remnant TRL clearance. Here we report a detailed interrogation of the mechanism of TRL lowering by the APOC3 Ala43Thr (A43T) variant, the only missense (rather than protein-truncating) variant in APOC3 reported to be TG lowering and protective against CHD. We found that both human APOC3 A43T heterozygotes and mice expressing human APOC3 A43T display markedly reduced circulating apoC-III levels. In mice, this reduction is due to impaired binding of A43T apoC-III to lipoproteins and accelerated renal catabolism of free apoC-III. Moreover, the reduced content of apoC-III in TRLs resulted in accelerated clearance of circulating TRLs. On the basis of this protective mechanism, we developed a monoclonal antibody targeting lipoprotein-bound human apoC-III that promotes circulating apoC-III clearance in mice expressing human APOC3 and enhances TRL catabolism in vivo. These data reveal the molecular mechanism by which a missense variant in APOC3 causes reduced circulating TG levels and, hence, protects from CHD. This protective mechanism has the potential to be exploited as a new therapeutic approach to reduce apoC-III levels and circulating TRL burden.
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Affiliation(s)
- Sumeet A Khetarpal
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Xuemei Zeng
- Biomedical Mass Spectrometry Center, Schools of the Health Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - John S Millar
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Cecilia Vitali
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Amritha Varshini Hanasoge Somasundara
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Paolo Zanoni
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | | | | | | | - Zhiyuan Sun
- Biomedical Mass Spectrometry Center, Schools of the Health Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | | | | | - Gina M Peloso
- Department of Biostatistics, Boston University School of Public Health, Boston, Massachusetts, USA
| | - Pradeep Natarajan
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, Massachusetts, USA
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
- Program in Medical and Population Genetics, Broad Institute, Cambridge, Massachusetts, USA
| | - Marina Cuchel
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Sissel Lund-Katz
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Michael C Phillips
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Alan R Tall
- Division of Molecular Medicine, Department of Medicine, Columbia University, New York, New York, USA
| | - Sekar Kathiresan
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, Massachusetts, USA
- Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA
- Program in Medical and Population Genetics, Broad Institute, Cambridge, Massachusetts, USA
| | | | - Nathan A Yates
- Biomedical Mass Spectrometry Center, Schools of the Health Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Cell Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Daniel J Rader
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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12
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Castro-Sánchez S, Álvarez-Satta M, Tohamy MA, Beltran S, Derdak S, Valverde D. Whole exome sequencing as a diagnostic tool for patients with ciliopathy-like phenotypes. PLoS One 2017; 12:e0183081. [PMID: 28800606 PMCID: PMC5553726 DOI: 10.1371/journal.pone.0183081] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 07/29/2017] [Indexed: 12/13/2022] Open
Abstract
Ciliopathies are a group of rare disorders characterized by a high genetic and phenotypic variability, which complicates their molecular diagnosis. Hence the need to use the latest powerful approaches to faster identify the genetic defect in these patients. We applied whole exome sequencing to six consanguineous families clinically diagnosed with ciliopathy-like disease, and for which mutations in predominant Bardet-Biedl syndrome (BBS) genes had previously been excluded. Our strategy, based on first applying several filters to ciliary variants and using many of the bioinformatics tools available, allowed us to identify causal mutations in BBS2, ALMS1 and CRB1 genes in four families, thus confirming the molecular diagnosis of ciliopathy. In the remaining two families, after first rejecting the presence of pathogenic variants in common cilia-related genes, we adopted a new filtering strategy combined with prioritisation tools to rank the final candidate genes for each case. Thus, we propose CORO2B, LMO7 and ZNF17 as novel candidate ciliary genes, but further functional studies will be needed to confirm their role. Our data show the usefulness of this strategy to diagnose patients with unclear phenotypes, and therefore the success of applying such technologies to achieve a rapid and reliable molecular diagnosis, improving genetic counselling for these patients. In addition, the described pipeline also highlights the common pitfalls associated to the large volume of data we have to face and the difficulty of assigning a functional role to these changes, hence the importance of designing the most appropriate strategy according to each case.
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Affiliation(s)
- Sheila Castro-Sánchez
- Departamento de Bioquímica, Genética e Inmunología, Facultad de Biología, Universidad de Vigo, Vigo, Spain
- Research Group of Rare Diseases & Pediatric Medicine, Instituto de Investigación Sanitaria Galicia Sur (IISGS), SERGAS-UVIGO, Hospital Álvaro Cunqueiro, Vigo, Spain
- Centro de Investigaciones Biomédicas (CINBIO) (Centro Singular de Investigación de Galicia), Universidad de Vigo, Vigo, Spain
| | - María Álvarez-Satta
- Departamento de Bioquímica, Genética e Inmunología, Facultad de Biología, Universidad de Vigo, Vigo, Spain
- Research Group of Rare Diseases & Pediatric Medicine, Instituto de Investigación Sanitaria Galicia Sur (IISGS), SERGAS-UVIGO, Hospital Álvaro Cunqueiro, Vigo, Spain
- Centro de Investigaciones Biomédicas (CINBIO) (Centro Singular de Investigación de Galicia), Universidad de Vigo, Vigo, Spain
| | - Mohamed A. Tohamy
- Departamento de Bioquímica, Genética e Inmunología, Facultad de Biología, Universidad de Vigo, Vigo, Spain
| | - Sergi Beltran
- CNAG-CRG, Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Sophia Derdak
- CNAG-CRG, Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Diana Valverde
- Departamento de Bioquímica, Genética e Inmunología, Facultad de Biología, Universidad de Vigo, Vigo, Spain
- Research Group of Rare Diseases & Pediatric Medicine, Instituto de Investigación Sanitaria Galicia Sur (IISGS), SERGAS-UVIGO, Hospital Álvaro Cunqueiro, Vigo, Spain
- Centro de Investigaciones Biomédicas (CINBIO) (Centro Singular de Investigación de Galicia), Universidad de Vigo, Vigo, Spain
- * E-mail:
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13
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Yang XR, Devi BCR, Sung H, Guida J, Mucaki EJ, Xiao Y, Best A, Garland L, Xie Y, Hu N, Rodriguez-Herrera M, Wang C, Jones K, Luo W, Hicks B, Tang TS, Moitra K, Rogan PK, Dean M. Prevalence and spectrum of germline rare variants in BRCA1/2 and PALB2 among breast cancer cases in Sarawak, Malaysia. Breast Cancer Res Treat 2017; 165:687-697. [PMID: 28664506 DOI: 10.1007/s10549-017-4356-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2017] [Accepted: 06/23/2017] [Indexed: 12/29/2022]
Abstract
PURPOSE To characterize the spectrum of germline mutations in BRCA1, BRCA2, and PALB2 in population-based unselected breast cancer cases in an Asian population. METHODS Germline DNA from 467 breast cancer patients in Sarawak General Hospital, Malaysia, where 93% of the breast cancer patients in Sarawak are treated, was sequenced for the entire coding region of BRCA1; BRCA2; PALB2; Exons 6, 7, and 8 of TP53; and Exons 7 and 8 of PTEN. Pathogenic variants included known pathogenic variants in ClinVar, loss of function variants, and variants that disrupt splice site. RESULTS We found 27 pathogenic variants (11 BRCA1, 10 BRCA2, 4 PALB2, and 2 TP53) in 34 patients, which gave a prevalence of germline mutations of 2.8, 3.23, and 0.86% for BRCA1, BRCA2, and PALB2, respectively. Compared to mutation non-carriers, BRCA1 mutation carriers were more likely to have an earlier age at onset, triple-negative subtype, and lower body mass index, whereas BRCA2 mutation carriers were more likely to have a positive family history. Mutation carrier cases had worse survival compared to non-carriers; however, the association was mostly driven by stage and tumor subtype. We also identified 19 variants of unknown significance, and some of them were predicted to alter splicing or transcription factor binding sites. CONCLUSION Our data provide insight into the genetics of breast cancer in this understudied group and suggest the need for modifying genetic testing guidelines for this population with a much younger age at diagnosis and more limited resources compared with Caucasian populations.
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Affiliation(s)
- Xiaohong R Yang
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, NCI/NIH, Bethesda, Rockville, MD, USA.
| | - Beena C R Devi
- Department of Radiotherapy, Oncology and Palliative Care, Sarawak General Hospital, Kuching, Sarawak, Malaysia
| | - Hyuna Sung
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, NCI/NIH, Bethesda, Rockville, MD, USA
| | - Jennifer Guida
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, NCI/NIH, Bethesda, Rockville, MD, USA
| | - Eliseos J Mucaki
- Department of Biochemistry, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, Canada
| | - Yanzi Xiao
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, NCI/NIH, Bethesda, Rockville, MD, USA
| | - Ana Best
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, NCI/NIH, Bethesda, Rockville, MD, USA
| | - Lisa Garland
- Cancer Genomics Research Laboratory, Leidos Biomedical Research, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Yi Xie
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, NCI/NIH, Bethesda, Rockville, MD, USA
| | - Nan Hu
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, NCI/NIH, Bethesda, Rockville, MD, USA
| | - Maria Rodriguez-Herrera
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, NCI/NIH, Bethesda, Rockville, MD, USA
| | - Chaoyu Wang
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, NCI/NIH, Bethesda, Rockville, MD, USA
| | - Kristine Jones
- Cancer Genomics Research Laboratory, Leidos Biomedical Research, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Wen Luo
- Cancer Genomics Research Laboratory, Leidos Biomedical Research, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Belynda Hicks
- Cancer Genomics Research Laboratory, Leidos Biomedical Research, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Tieng Swee Tang
- Department of Radiotherapy, Oncology and Palliative Care, Sarawak General Hospital, Kuching, Sarawak, Malaysia
| | - Karobi Moitra
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, NCI/NIH, Bethesda, Rockville, MD, USA.,Department of Biology, Trinity Washington University, Washington, DC, USA
| | - Peter K Rogan
- Department of Biochemistry, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, Canada
| | - Michael Dean
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, NCI/NIH, Bethesda, Rockville, MD, USA
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14
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Álvarez-Satta M, Castro-Sánchez S, Pousada G, Valverde D. Functional analysis by minigene assay of putative splicing variants found in Bardet-Biedl syndrome patients. J Cell Mol Med 2017; 21:2268-2275. [PMID: 28502102 PMCID: PMC5618670 DOI: 10.1111/jcmm.13147] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 01/30/2017] [Indexed: 01/05/2023] Open
Abstract
Bardet–Biedl syndrome (BBS) and Alström syndrome (ALMS) are rare diseases belonging to the group of ciliopathies. Although mutational screening studies of BBS/ALMS cohorts have been extensively reported, little is known about the functional effect of those changes. Thus, splicing variants are estimated to represent 15% of disease‐causing mutations, and there is growing evidence that many exonic changes are really splicing variants misclassified. In this study, we aimed to analyse for the first time several variants in BBS2,ARL6/BBS3,BBS4 and ALMS1 genes predicted to produce aberrant splicing by minigene assay. We found discordance between bioinformatics analysis and experimental data when comparing wild‐type and mutant constructs. Remarkably, we identified nonsense variants presumably resistant to nonsense‐mediated decay, even when a premature termination codon would be introduced in the second amino acid (p.(G2*) mutation in ARL6/BBS3 gene). As a whole, we report one of the first functional studies of BBS/ALMS1 variants using minigene assay, trying to elucidate their role in disease. Functional studies of variants identified in BBS and ALMS patients are essential for their proper classification and subsequent genetic counselling and could also be the start point for new therapeutic approaches, currently based only on symptomatic treatment.
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Affiliation(s)
- María Álvarez-Satta
- Grupo de Biomarcadores Moleculares (BB1), Departamento de Bioquímica, Genética e Inmunología, Facultad de Biología, Universidad de Vigo, Vigo, Spain.,Instituto de Investigación Sanitaria Galicia Sur (IISGS), Vigo, Spain
| | - Sheila Castro-Sánchez
- Grupo de Biomarcadores Moleculares (BB1), Departamento de Bioquímica, Genética e Inmunología, Facultad de Biología, Universidad de Vigo, Vigo, Spain.,Instituto de Investigación Sanitaria Galicia Sur (IISGS), Vigo, Spain
| | - Guillermo Pousada
- Grupo de Biomarcadores Moleculares (BB1), Departamento de Bioquímica, Genética e Inmunología, Facultad de Biología, Universidad de Vigo, Vigo, Spain.,Instituto de Investigación Sanitaria Galicia Sur (IISGS), Vigo, Spain
| | - Diana Valverde
- Grupo de Biomarcadores Moleculares (BB1), Departamento de Bioquímica, Genética e Inmunología, Facultad de Biología, Universidad de Vigo, Vigo, Spain.,Instituto de Investigación Sanitaria Galicia Sur (IISGS), Vigo, Spain
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15
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Mucaki EJ, Caminsky NG, Perri AM, Lu R, Laederach A, Halvorsen M, Knoll JHM, Rogan PK. A unified analytic framework for prioritization of non-coding variants of uncertain significance in heritable breast and ovarian cancer. BMC Med Genomics 2016; 9:19. [PMID: 27067391 PMCID: PMC4828881 DOI: 10.1186/s12920-016-0178-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 03/15/2016] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Sequencing of both healthy and disease singletons yields many novel and low frequency variants of uncertain significance (VUS). Complete gene and genome sequencing by next generation sequencing (NGS) significantly increases the number of VUS detected. While prior studies have emphasized protein coding variants, non-coding sequence variants have also been proven to significantly contribute to high penetrance disorders, such as hereditary breast and ovarian cancer (HBOC). We present a strategy for analyzing different functional classes of non-coding variants based on information theory (IT) and prioritizing patients with large intragenic deletions. METHODS We captured and enriched for coding and non-coding variants in genes known to harbor mutations that increase HBOC risk. Custom oligonucleotide baits spanning the complete coding, non-coding, and intergenic regions 10 kb up- and downstream of ATM, BRCA1, BRCA2, CDH1, CHEK2, PALB2, and TP53 were synthesized for solution hybridization enrichment. Unique and divergent repetitive sequences were sequenced in 102 high-risk, anonymized patients without identified mutations in BRCA1/2. Aside from protein coding and copy number changes, IT-based sequence analysis was used to identify and prioritize pathogenic non-coding variants that occurred within sequence elements predicted to be recognized by proteins or protein complexes involved in mRNA splicing, transcription, and untranslated region (UTR) binding and structure. This approach was supplemented by in silico and laboratory analysis of UTR structure. RESULTS 15,311 unique variants were identified, of which 245 occurred in coding regions. With the unified IT-framework, 132 variants were identified and 87 functionally significant VUS were further prioritized. An intragenic 32.1 kb interval in BRCA2 that was likely hemizygous was detected in one patient. We also identified 4 stop-gain variants and 3 reading-frame altering exonic insertions/deletions (indels). CONCLUSIONS We have presented a strategy for complete gene sequence analysis followed by a unified framework for interpreting non-coding variants that may affect gene expression. This approach distills large numbers of variants detected by NGS to a limited set of variants prioritized as potential deleterious changes.
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Affiliation(s)
- Eliseos J Mucaki
- Department of Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, ON, N6A 2C1, Canada
| | - Natasha G Caminsky
- Department of Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, ON, N6A 2C1, Canada
| | - Ami M Perri
- Department of Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, ON, N6A 2C1, Canada
| | - Ruipeng Lu
- Department of Computer Science, Faculty of Science, Western University, London, N6A 2C1, Canada
| | - Alain Laederach
- Department of Biology, University of North Carolina, Chapel Hill, NC, 27599-3290, USA
| | - Matthew Halvorsen
- Institute for Genomic Medicine, Columbia University Medical Center, New York, NY, 10032, USA
| | - Joan H M Knoll
- Department of Pathology and Laboratory Medicine, Schulich School of Medicine and Dentistry, Western University, London, N6A 2C1, Canada
- Cytognomix Inc., London, Canada
| | - Peter K Rogan
- Department of Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, ON, N6A 2C1, Canada.
- Department of Computer Science, Faculty of Science, Western University, London, N6A 2C1, Canada.
- Cytognomix Inc., London, Canada.
- Department of Oncology, Schulich School of Medicine and Dentistry, Western University, London, N6A 2C1, Canada.
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16
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Peterlongo P, Catucci I, Colombo M, Caleca L, Mucaki E, Bogliolo M, Marin M, Damiola F, Bernard L, Pensotti V, Volorio S, Dall'Olio V, Meindl A, Bartram C, Sutter C, Surowy H, Sornin V, Dondon MG, Eon-Marchais S, Stoppa-Lyonnet D, Andrieu N, Sinilnikova OM, Mitchell G, James PA, Thompson E, Marchetti M, Verzeroli C, Tartari C, Capone GL, Putignano AL, Genuardi M, Medici V, Marchi I, Federico M, Tognazzo S, Matricardi L, Agata S, Dolcetti R, Della Puppa L, Cini G, Gismondi V, Viassolo V, Perfumo C, Mencarelli MA, Baldassarri M, Peissel B, Roversi G, Silvestri V, Rizzolo P, Spina F, Vivanet C, Tibiletti MG, Caligo MA, Gambino G, Tommasi S, Pilato B, Tondini C, Corna C, Bonanni B, Barile M, Osorio A, Benitez J, Balestrino L, Ottini L, Manoukian S, Pierotti MA, Renieri A, Varesco L, Couch FJ, Wang X, Devilee P, Hilbers FS, van Asperen CJ, Viel A, Montagna M, Cortesi L, Diez O, Balmaña J, Hauke J, Schmutzler RK, Papi L, Pujana MA, Lázaro C, Falanga A, Offit K, Vijai J, Campbell I, Burwinkel B, Kvist A, Ehrencrona H, Mazoyer S, Pizzamiglio S, Verderio P, Surralles J, Rogan PK, Radice P. FANCM c.5791C>T nonsense mutation (rs144567652) induces exon skipping, affects DNA repair activity and is a familial breast cancer risk factor. Hum Mol Genet 2015; 24:5345-55. [PMID: 26130695 DOI: 10.1093/hmg/ddv251] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 06/25/2015] [Indexed: 11/15/2022] Open
Abstract
Numerous genetic factors that influence breast cancer risk are known. However, approximately two-thirds of the overall familial risk remain unexplained. To determine whether some of the missing heritability is due to rare variants conferring high to moderate risk, we tested for an association between the c.5791C>T nonsense mutation (p.Arg1931*; rs144567652) in exon 22 of FANCM gene and breast cancer. An analysis of genotyping data from 8635 familial breast cancer cases and 6625 controls from different countries yielded an association between the c.5791C>T mutation and breast cancer risk [odds ratio (OR) = 3.93 (95% confidence interval (CI) = 1.28-12.11; P = 0.017)]. Moreover, we performed two meta-analyses of studies from countries with carriers in both cases and controls and of all available data. These analyses showed breast cancer associations with OR = 3.67 (95% CI = 1.04-12.87; P = 0.043) and OR = 3.33 (95% CI = 1.09-13.62; P = 0.032), respectively. Based on information theory-based prediction, we established that the mutation caused an out-of-frame deletion of exon 22, due to the creation of a binding site for the pre-mRNA processing protein hnRNP A1. Furthermore, genetic complementation analyses showed that the mutation influenced the DNA repair activity of the FANCM protein. In summary, we provide evidence for the first time showing that the common p.Arg1931* loss-of-function variant in FANCM is a risk factor for familial breast cancer.
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Affiliation(s)
- Paolo Peterlongo
- IFOM, the FIRC Institute of Molecular Oncology, Milan, Italy, Unit of Molecular Bases of Genetic Risk and Genetic Testing, Department of Preventive and Predictive Medicine,
| | - Irene Catucci
- IFOM, the FIRC Institute of Molecular Oncology, Milan, Italy, Unit of Molecular Bases of Genetic Risk and Genetic Testing, Department of Preventive and Predictive Medicine
| | - Mara Colombo
- Unit of Molecular Bases of Genetic Risk and Genetic Testing, Department of Preventive and Predictive Medicine
| | - Laura Caleca
- Unit of Molecular Bases of Genetic Risk and Genetic Testing, Department of Preventive and Predictive Medicine
| | - Eliseos Mucaki
- Department of Biochemistry, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Massimo Bogliolo
- Genome Instability and DNA Repair Group, Department of Genetics and Microbiology, Universitat Autònoma de Barcelona and Center for Biomedical Network Research on Rare Diseases (CIBERER), Barcelona, Spain
| | - Maria Marin
- Genome Instability and DNA Repair Group, Department of Genetics and Microbiology, Universitat Autònoma de Barcelona and Center for Biomedical Network Research on Rare Diseases (CIBERER), Barcelona, Spain
| | - Francesca Damiola
- Cancer Research Centre of Lyon, CNRS UMR5286, INSERM U1052, Université Claude Bernard Lyon 1, Centre Léon Bérard, Lyon, France
| | - Loris Bernard
- Department of Experimental Oncology and Cogentech, Cancer Genetic Test Laboratory, Milan, Italy
| | - Valeria Pensotti
- IFOM, the FIRC Institute of Molecular Oncology, Milan, Italy, Cogentech, Cancer Genetic Test Laboratory, Milan, Italy
| | - Sara Volorio
- IFOM, the FIRC Institute of Molecular Oncology, Milan, Italy, Cogentech, Cancer Genetic Test Laboratory, Milan, Italy
| | - Valentina Dall'Olio
- IFOM, the FIRC Institute of Molecular Oncology, Milan, Italy, Cogentech, Cancer Genetic Test Laboratory, Milan, Italy
| | - Alfons Meindl
- Division of Gynaecology and Obstetrics, Technische Universität München, Munich, Germany
| | - Claus Bartram
- Institute of Human Genetics, University of Heidelberg, Heidelberg, Germany
| | - Christian Sutter
- Institute of Human Genetics, University of Heidelberg, Heidelberg, Germany
| | - Harald Surowy
- Molecular Biology of Breast Cancer, Department of Obstetrics and Gynecology, University Hospital Heidelberg, Heidelberg, Germany, Molecular Epidemiology Group, C080, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Valérie Sornin
- Cancer Research Centre of Lyon, CNRS UMR5286, INSERM U1052, Université Claude Bernard Lyon 1, Centre Léon Bérard, Lyon, France
| | - Marie-Gabrielle Dondon
- INSERM, U900, Paris, France, Institut Curie, Paris, France, Mines ParisTech, Fontainebleau, France
| | - Séverine Eon-Marchais
- INSERM, U900, Paris, France, Institut Curie, Paris, France, Mines ParisTech, Fontainebleau, France
| | - Dominique Stoppa-Lyonnet
- Service de Génétique Oncologique, Institut Curie, Paris, France, INSERM, U830, Paris, France, Université Paris-Descartes, Paris, France
| | - Nadine Andrieu
- INSERM, U900, Paris, France, Institut Curie, Paris, France, Mines ParisTech, Fontainebleau, France
| | - Olga M Sinilnikova
- Cancer Research Centre of Lyon, CNRS UMR5286, INSERM U1052, Université Claude Bernard Lyon 1, Centre Léon Bérard, Lyon, France, Unité Mixte de Génétique Constitutionnelle des Cancers Fréquents, Centre Hospitalier Universitaire de Lyon/Centre Léon Bérard, Lyon, France
| | | | - Gillian Mitchell
- Familial Cancer Centre, Sir Peter MacCallum Department of Oncology and
| | - Paul A James
- Familial Cancer Centre, Sir Peter MacCallum Department of Oncology and
| | - Ella Thompson
- Cancer Genetics Laboratory and Sir Peter MacCallum Department of Oncology and
| | | | | | | | - Cristina Verzeroli
- Kathleen Cunningham Foundation Consortium for Research into Familial Breast Cancer (kConFab), Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia
| | - Carmen Tartari
- Department of Immunohematology and Transfusion Medicine and
| | - Gabriele Lorenzo Capone
- Dipartimento di Scienze Biomediche Sperimentali e Cliniche, Università di Firenze, Firenze, Italy, FiorGen Foundation for Pharmacogenomics, Sesto Fiorentino, Italy
| | - Anna Laura Putignano
- Dipartimento di Scienze Biomediche Sperimentali e Cliniche, Università di Firenze, Firenze, Italy, FiorGen Foundation for Pharmacogenomics, Sesto Fiorentino, Italy
| | - Maurizio Genuardi
- Dipartimento di Scienze Biomediche Sperimentali e Cliniche, Università di Firenze, Firenze, Italy, FiorGen Foundation for Pharmacogenomics, Sesto Fiorentino, Italy, Institute of Medical Genetics, 'A. Gemelli' School of Medicine, Catholic University, Rome, Italy
| | - Veronica Medici
- Dipartimento di Oncologia, Ematologia e Malattie dell'Apparato Respiratorio, Università di Modena e Reggio Emilia, Modena, Italy
| | - Isabella Marchi
- Dipartimento di Oncologia, Ematologia e Malattie dell'Apparato Respiratorio, Università di Modena e Reggio Emilia, Modena, Italy
| | - Massimo Federico
- Dipartimento di Oncologia, Ematologia e Malattie dell'Apparato Respiratorio, Università di Modena e Reggio Emilia, Modena, Italy
| | - Silvia Tognazzo
- Immunology and Molecular Oncology Unit, Istituto Oncologico Veneto IOV - IRCCS, Padua, Italy
| | - Laura Matricardi
- Immunology and Molecular Oncology Unit, Istituto Oncologico Veneto IOV - IRCCS, Padua, Italy
| | - Simona Agata
- Immunology and Molecular Oncology Unit, Istituto Oncologico Veneto IOV - IRCCS, Padua, Italy
| | | | - Lara Della Puppa
- Unit of Experimental Oncology 1, CRO Aviano National Cancer Institute, Aviano (PN), Italy
| | - Giulia Cini
- Unit of Experimental Oncology 1, CRO Aviano National Cancer Institute, Aviano (PN), Italy
| | - Viviana Gismondi
- Unit of Hereditary Cancers, IRCCS AOU San Martino - IST, Genoa, Italy
| | - Valeria Viassolo
- Unit of Hereditary Cancers, IRCCS AOU San Martino - IST, Genoa, Italy
| | - Chiara Perfumo
- Unit of Hereditary Cancers, IRCCS AOU San Martino - IST, Genoa, Italy
| | - Maria Antonietta Mencarelli
- Medical Genetics, University of Siena, Siena, Italy, Genetica Medica, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Margherita Baldassarri
- Medical Genetics, University of Siena, Siena, Italy, Genetica Medica, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Bernard Peissel
- Unit of Medical Genetics, Department of Preventive and Predictive Medicine
| | - Gaia Roversi
- Unit of Medical Genetics, Department of Preventive and Predictive Medicine
| | | | - Piera Rizzolo
- Department of Molecular Medicine, Sapienza University of Rome, Rome, Italy
| | | | | | | | - Maria Adelaide Caligo
- Section of Genetic Oncology, University Hospital and University of Pisa, Pisa, Italy
| | - Gaetana Gambino
- Section of Genetic Oncology, University Hospital and University of Pisa, Pisa, Italy
| | - Stefania Tommasi
- IRCCS Istituto Tumori 'Giovanni Paolo II', Molecular Genetics Laboratory, Bari, Italy
| | - Brunella Pilato
- IRCCS Istituto Tumori 'Giovanni Paolo II', Molecular Genetics Laboratory, Bari, Italy
| | - Carlo Tondini
- Unit of Medical Oncology, Azienda Ospedaliera Papa Giovanni XXIII, Bergamo, Italy
| | - Chiara Corna
- Unit of Medical Oncology, Azienda Ospedaliera Papa Giovanni XXIII, Bergamo, Italy
| | - Bernardo Bonanni
- Division of Cancer Prevention and Genetics, Istituto Europeo di Oncologia, Milan, Italy
| | - Monica Barile
- Division of Cancer Prevention and Genetics, Istituto Europeo di Oncologia, Milan, Italy
| | - Ana Osorio
- Human Cancer Genetics Programme, Spanish National Cancer Centre (CNIO), Madrid, Spain, Spanish Genotyping Centre (CEGEN), Madrid, Spain
| | - Javier Benitez
- Human Cancer Genetics Programme, Spanish National Cancer Centre (CNIO), Madrid, Spain, Spanish Genotyping Centre (CEGEN), Madrid, Spain
| | | | - Laura Ottini
- Department of Molecular Medicine, Sapienza University of Rome, Rome, Italy
| | | | | | - Alessandra Renieri
- Medical Genetics, University of Siena, Siena, Italy, Genetica Medica, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Liliana Varesco
- Unit of Hereditary Cancers, IRCCS AOU San Martino - IST, Genoa, Italy
| | - Fergus J Couch
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
| | - Xianshu Wang
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
| | - Peter Devilee
- Department of Human Genetics, Department of Pathology and
| | | | - Christi J van Asperen
- Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Alessandra Viel
- Unit of Experimental Oncology 1, CRO Aviano National Cancer Institute, Aviano (PN), Italy
| | - Marco Montagna
- Immunology and Molecular Oncology Unit, Istituto Oncologico Veneto IOV - IRCCS, Padua, Italy
| | - Laura Cortesi
- Dipartimento di Oncologia, Ematologia e Malattie dell'Apparato Respiratorio, Università di Modena e Reggio Emilia, Modena, Italy
| | - Orland Diez
- Oncogenetics Group, Hospital Universitari de la Vall d'Hebron, Barcelona, Spain, Vall d́Hebron Institute of Oncology (VHIO), Barcelona, Spain, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Judith Balmaña
- Vall d́Hebron Institute of Oncology (VHIO), Barcelona, Spain, Department of Medical Oncology, Hospital Universitari de la Vall d́Hebron, Barcelona, Spain
| | - Jan Hauke
- Center for Familial Breast and Ovarian Cancer, University Hospital of Cologne, Cologne, Germany
| | - Rita K Schmutzler
- Center for Familial Breast and Ovarian Cancer, University Hospital of Cologne, Cologne, Germany
| | - Laura Papi
- Dipartimento di Scienze Biomediche Sperimentali e Cliniche, Università di Firenze, Firenze, Italy
| | | | - Conxi Lázaro
- Catalan Institute of Oncology - IDIBELL, Barcelona, Spain
| | - Anna Falanga
- Department of Immunohematology and Transfusion Medicine and
| | - Kenneth Offit
- Clinical Genetics Service, Department of Medicine and Department of Cancer Biology and Genetics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Joseph Vijai
- Clinical Genetics Service, Department of Medicine and Department of Cancer Biology and Genetics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Ian Campbell
- Cancer Genetics Laboratory and Sir Peter MacCallum Department of Oncology and Department of Pathology, University of Melbourne, Parkville, Victoria, Australia
| | - Barbara Burwinkel
- Molecular Biology of Breast Cancer, Department of Obstetrics and Gynecology, University Hospital Heidelberg, Heidelberg, Germany, Molecular Epidemiology Group, C080, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Anders Kvist
- Division of Oncology, Department of Clinical Sciences
| | - Hans Ehrencrona
- Department of Clinical Genetics, Laboratory Medicine, Office for Medical Services and Department of Clinical Genetics, Lund University, Lund, Sweden
| | - Sylvie Mazoyer
- Cancer Research Centre of Lyon, CNRS UMR5286, INSERM U1052, Université Claude Bernard Lyon 1, Centre Léon Bérard, Lyon, France
| | - Sara Pizzamiglio
- Unit of Medical Statistics, Biometry and Bioinformatics, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
| | - Paolo Verderio
- Unit of Medical Statistics, Biometry and Bioinformatics, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
| | - Jordi Surralles
- Genome Instability and DNA Repair Group, Department of Genetics and Microbiology, Universitat Autònoma de Barcelona and Center for Biomedical Network Research on Rare Diseases (CIBERER), Barcelona, Spain
| | - Peter K Rogan
- Department of Biochemistry, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Paolo Radice
- IFOM, the FIRC Institute of Molecular Oncology, Milan, Italy, Unit of Molecular Bases of Genetic Risk and Genetic Testing, Department of Preventive and Predictive Medicine
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17
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Caminsky NG, Mucaki EJ, Rogan PK. Interpretation of mRNA splicing mutations in genetic disease: review of the literature and guidelines for information-theoretical analysis. F1000Res 2015. [DOI: 10.12688/f1000research.5654.2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The interpretation of genomic variants has become one of the paramount challenges in the post-genome sequencing era. In this review we summarize nearly 20 years of research on the applications of information theory (IT) to interpret coding and non-coding mutations that alter mRNA splicing in rare and common diseases. We compile and summarize the spectrum of published variants analyzed by IT, to provide a broad perspective of the distribution of deleterious natural and cryptic splice site variants detected, as well as those affecting splicing regulatory sequences. Results for natural splice site mutations can be interrogated dynamically with Splicing Mutation Calculator, a companion software program that computes changes in information content for any splice site substitution, linked to corresponding publications containing these mutations. The accuracy of IT-based analysis was assessed in the context of experimentally validated mutations. Because splice site information quantifies binding affinity, IT-based analyses can discern the differences between variants that account for the observed reduced (leaky) versus abolished mRNA splicing. We extend this principle by comparing predicted mutations in natural, cryptic, and regulatory splice sites with observed deleterious phenotypic and benign effects. Our analysis of 1727 variants revealed a number of general principles useful for ensuring portability of these analyses and accurate input and interpretation of mutations. We offer guidelines for optimal use of IT software for interpretation of mRNA splicing mutations.
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18
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Bonini J, Varilh J, Raynal C, Thèze C, Beyne E, Audrezet MP, Ferec C, Bienvenu T, Girodon E, Tuffery-Giraud S, Des Georges M, Claustres M, Taulan-Cadars M. Small-scale high-throughput sequencing-based identification of new therapeutic tools in cystic fibrosis. Genet Med 2015; 17:796-806. [PMID: 25569440 DOI: 10.1038/gim.2014.194] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 11/24/2014] [Indexed: 12/23/2022] Open
Abstract
PURPOSE Although 97-99% of CFTR mutations have been identified, great efforts must be made to detect yet-unidentified mutations. METHODS We developed a small-scale next-generation sequencing approach for reliably and quickly scanning the entire gene, including noncoding regions, to identify new mutations. We applied this approach to 18 samples from patients suffering from cystic fibrosis (CF) in whom only one mutation had hitherto been identified. RESULTS Using an in-house bioinformatics pipeline, we could rapidly identify a second disease-causing CFTR mutation for 16 of 18 samples. Of them, c.1680-883A>G was found in three unrelated CF patients. Analysis of minigenes and patients' transcripts showed that this mutation results in aberrantly spliced transcripts because of the inclusion of a pseudoexon. It is located only three base pairs from the c.1680-886A>G mutation (1811+1.6kbA>G), the fourth most frequent mutation in southwestern Europe. We next tested the effect of antisense oligonucleotides targeting splice sites on these two mutations on pseudoexon skipping. Oligonucleotide transfection resulted in the restoration of the full-length, in-frame CFTR transcript, demonstrating the effect of antisense oligonucleotide-induced pseudoexon skipping in CF. CONCLUSION Our data confirm the importance of analyzing noncoding regions to find unidentified mutations, which is essential to designing targeted therapeutic approaches.
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Affiliation(s)
- Jennifer Bonini
- INSERM U827, Laboratoire de Génétique de Maladies Rares, Montpellier, France.,Université Montpellier I, UFR de Médecine, Montpellier, France
| | - Jessica Varilh
- INSERM U827, Laboratoire de Génétique de Maladies Rares, Montpellier, France.,Laboratoire de Génétique Moléculaire, CHU Montpellier, Montpellier, France
| | - Caroline Raynal
- INSERM U827, Laboratoire de Génétique de Maladies Rares, Montpellier, France.,Laboratoire de Génétique Moléculaire, CHU Montpellier, Montpellier, France
| | - Corinne Thèze
- INSERM U827, Laboratoire de Génétique de Maladies Rares, Montpellier, France.,Laboratoire de Génétique Moléculaire, CHU Montpellier, Montpellier, France
| | - Emmanuelle Beyne
- INSERM U827, Laboratoire de Génétique de Maladies Rares, Montpellier, France.,Laboratoire de Génétique Moléculaire, CHU Montpellier, Montpellier, France
| | | | - Claude Ferec
- Laboratoire de Génétique Moléculaire et d'Histocompatibilité, CHRU, Brest, France
| | - Thierry Bienvenu
- AP-HP, Service de Biochimie et Génétique Moléculaires, Groupe Hospitalier Cochin Broca Hôtel Dieu, Paris, France
| | - Emmanuelle Girodon
- AP-HP, Service de Biochimie et Génétique Moléculaires, Groupe Hospitalier Cochin Broca Hôtel Dieu, Paris, France
| | - Sylvie Tuffery-Giraud
- INSERM U827, Laboratoire de Génétique de Maladies Rares, Montpellier, France.,Université Montpellier I, UFR de Médecine, Montpellier, France
| | - Marie Des Georges
- INSERM U827, Laboratoire de Génétique de Maladies Rares, Montpellier, France.,Laboratoire de Génétique Moléculaire, CHU Montpellier, Montpellier, France
| | - Mireille Claustres
- INSERM U827, Laboratoire de Génétique de Maladies Rares, Montpellier, France.,Université Montpellier I, UFR de Médecine, Montpellier, France
| | - Magali Taulan-Cadars
- INSERM U827, Laboratoire de Génétique de Maladies Rares, Montpellier, France.,Université Montpellier I, UFR de Médecine, Montpellier, France
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19
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Caminsky N, Mucaki EJ, Rogan PK. Interpretation of mRNA splicing mutations in genetic disease: review of the literature and guidelines for information-theoretical analysis. F1000Res 2014; 3:282. [PMID: 25717368 PMCID: PMC4329672 DOI: 10.12688/f1000research.5654.1] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/10/2014] [Indexed: 12/14/2022] Open
Abstract
The interpretation of genomic variants has become one of the paramount challenges in the post-genome sequencing era. In this review we summarize nearly 20 years of research on the applications of information theory (IT) to interpret coding and non-coding mutations that alter mRNA splicing in rare and common diseases. We compile and summarize the spectrum of published variants analyzed by IT, to provide a broad perspective of the distribution of deleterious natural and cryptic splice site variants detected, as well as those affecting splicing regulatory sequences. Results for natural splice site mutations can be interrogated dynamically with Splicing Mutation Calculator, a companion software program that computes changes in information content for any splice site substitution, linked to corresponding publications containing these mutations. The accuracy of IT-based analysis was assessed in the context of experimentally validated mutations. Because splice site information quantifies binding affinity, IT-based analyses can discern the differences between variants that account for the observed reduced (leaky) versus abolished mRNA splicing. We extend this principle by comparing predicted mutations in natural, cryptic, and regulatory splice sites with observed deleterious phenotypic and benign effects. Our analysis of 1727 variants revealed a number of general principles useful for ensuring portability of these analyses and accurate input and interpretation of mutations. We offer guidelines for optimal use of IT software for interpretation of mRNA splicing mutations.
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Affiliation(s)
- Natasha Caminsky
- Department of Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, ON, N6A 2C1, Canada
| | - Eliseos J Mucaki
- Department of Biochemistry, Schulich School of Medicine and Dentistry, Western University, London, ON, N6A 2C1, Canada
| | - Peter K Rogan
- Departments of Biochemistry and Computer Science, Western University, London, ON, N6A 2C1, Canada
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20
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Splicing mutation analysis reveals previously unrecognized pathways in lymph node-invasive breast cancer. Sci Rep 2014; 4:7063. [PMID: 25394353 PMCID: PMC4231324 DOI: 10.1038/srep07063] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Accepted: 10/29/2014] [Indexed: 12/22/2022] Open
Abstract
Somatic mutations reported in large-scale breast cancer (BC) sequencing studies primarily consist of protein coding mutations. mRNA splicing mutation analyses have been limited in scope, despite their prevalence in Mendelian genetic disorders. We predicted splicing mutations in 442 BC tumour and matched normal exomes from The Cancer Genome Atlas Consortium (TCGA). These splicing defects were validated by abnormal expression changes in these tumours. Of the 5,206 putative mutations identified, exon skipping, leaky or cryptic splicing was confirmed for 988 variants. Pathway enrichment analysis of the mutated genes revealed mutations in 9 NCAM1-related pathways, which were significantly increased in samples with evidence of lymph node metastasis, but not in lymph node-negative tumours. We suggest that comprehensive reporting of DNA sequencing data should include non-trivial splicing analyses to avoid missing clinically-significant deleterious splicing mutations, which may reveal novel mutated pathways present in genetic disorders.
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21
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Paganini I, Chang VY, Capone GL, Vitte J, Benelli M, Barbetti L, Sestini R, Trevisson E, Hulsebos TJ, Giovannini M, Nelson SF, Papi L. Expanding the mutational spectrum of LZTR1 in schwannomatosis. Eur J Hum Genet 2014; 23:963-8. [PMID: 25335493 DOI: 10.1038/ejhg.2014.220] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 08/21/2014] [Accepted: 09/16/2014] [Indexed: 02/07/2023] Open
Abstract
Schwannomatosis is characterized by the development of multiple non-vestibular, non-intradermal schwannomas. Constitutional inactivating variants in two genes, SMARCB1 and, very recently, LZTR1, have been reported. We performed exome sequencing of 13 schwannomatosis patients from 11 families without SMARCB1 deleterious variants. We identified four individuals with heterozygous loss-of-function variants in LZTR1. Sequencing of the germline of 60 additional patients identified 18 additional heterozygous variants in LZTR1. We identified LZTR1 variants in 43% and 30% of familial (three of the seven families) and sporadic patients, respectively. In addition, we tested LZTR1 protein immunostaining in 22 tumors from nine unrelated patients with and without LZTR1 deleterious variants. Tumors from individuals with LZTR1 variants lost the protein expression in at least a subset of tumor cells, consistent with a tumor suppressor mechanism. In conclusion, our study demonstrates that molecular analysis of LZTR1 may contribute to the molecular characterization of schwannomatosis patients, in addition to NF2 mutational analysis and the detection of chromosome 22 losses in tumor tissue. It will be especially useful in differentiating schwannomatosis from mosaic Neurofibromatosis type 2 (NF2). However, the role of LZTR1 in the pathogenesis of schwannomatosis needs further elucidation.
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Affiliation(s)
- Irene Paganini
- Department of Biomedical Experimental and Clinical Sciences, Medical Genetics, University of Florence, Florence, Italy
| | - Vivian Y Chang
- Division of Hematology-Oncology, Department of Pediatrics, University of California Los Angeles, Los Angeles, CA, USA
| | - Gabriele L Capone
- 1] Department of Biomedical Experimental and Clinical Sciences, Medical Genetics, University of Florence, Florence, Italy [2] FIORGEN Fondazione Farmacogenomica Polo Scientifico, Sesto Fiorentino, Florence, Italy
| | - Jeremie Vitte
- Department of Head and Neck Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Matteo Benelli
- Diagnostic Genetics Unit, Azienda Ospedaliero-Universitaria 'Careggi', Florence, Italy
| | - Lorenzo Barbetti
- Department of Biomedical Experimental and Clinical Sciences, Medical Genetics, University of Florence, Florence, Italy
| | - Roberta Sestini
- Department of Biomedical Experimental and Clinical Sciences, Medical Genetics, University of Florence, Florence, Italy
| | - Eva Trevisson
- Department of Woman and Child Health, Clinical Genetics Unit, University of Padua, Padua, Italy
| | - Theo Jm Hulsebos
- Department of Genome Analysis, Academic Medical Center, Amsterdam, The Netherlands
| | - Marco Giovannini
- Department of Head and Neck Surgery, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Stanley F Nelson
- Department of Human Genetics, Pathology and Laboratory Medicine, and Psychiatry, University of California, Los Angeles, CA, USA
| | - Laura Papi
- Department of Biomedical Experimental and Clinical Sciences, Medical Genetics, University of Florence, Florence, Italy
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22
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Sharma N, Sosnay PR, Ramalho AS, Douville C, Franca A, Gottschalk LB, Park J, Lee M, Vecchio-Pagan B, Raraigh KS, Amaral MD, Karchin R, Cutting GR. Experimental assessment of splicing variants using expression minigenes and comparison with in silico predictions. Hum Mutat 2014; 35:1249-59. [PMID: 25066652 DOI: 10.1002/humu.22624] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 07/13/2014] [Indexed: 12/28/2022]
Abstract
Assessment of the functional consequences of variants near splice sites is a major challenge in the diagnostic laboratory. To address this issue, we created expression minigenes (EMGs) to determine the RNA and protein products generated by splice site variants (n = 10) implicated in cystic fibrosis (CF). Experimental results were compared with the splicing predictions of eight in silico tools. EMGs containing the full-length Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) coding sequence and flanking intron sequences generated wild-type transcript and fully processed protein in Human Embryonic Kidney (HEK293) and CF bronchial epithelial (CFBE41o-) cells. Quantification of variant induced aberrant mRNA isoforms was concordant using fragment analysis and pyrosequencing. The splicing patterns of c.1585-1G>A and c.2657+5G>A were comparable to those reported in primary cells from individuals bearing these variants. Bioinformatics predictions were consistent with experimental results for 9/10 variants (MES), 8/10 variants (NNSplice), and 7/10 variants (SSAT and Sroogle). Programs that estimate the consequences of mis-splicing predicted 11/16 (HSF and ASSEDA) and 10/16 (Fsplice and SplicePort) experimentally observed mRNA isoforms. EMGs provide a robust experimental approach for clinical interpretation of splice site variants and refinement of in silico tools.
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Affiliation(s)
- Neeraj Sharma
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
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23
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Viner C, Dorman SN, Shirley BC, Rogan PK. Validation of predicted mRNA splicing mutations using high-throughput transcriptome data. F1000Res 2014; 3:8. [PMID: 24741438 PMCID: PMC3983938 DOI: 10.12688/f1000research.3-8.v2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/03/2014] [Indexed: 01/20/2023] Open
Abstract
Interpretation of variants present in complete genomes or exomes reveals numerous sequence changes, only a fraction of which are likely to be pathogenic. Mutations have been traditionally inferred from allele frequencies and inheritance patterns in such data. Variants predicted to alter mRNA splicing can be validated by manual inspection of transcriptome sequencing data, however this approach is intractable for large datasets. These abnormal mRNA splicing patterns are characterized by reads demonstrating either exon skipping, cryptic splice site use, and high levels of intron inclusion, or combinations of these properties. We present, Veridical, an
in silico method for the automatic validation of DNA sequencing variants that alter mRNA splicing. Veridical performs statistically valid comparisons of the normalized read counts of abnormal RNA species in mutant versus non-mutant tissues. This leverages large numbers of control samples to corroborate the consequences of predicted splicing variants in complete genomes and exomes.
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Affiliation(s)
- Coby Viner
- Department of Computer Science, University of Western Ontario, London, Ontario, N6A 5B7, Canada
| | - Stephanie N Dorman
- Department of Biochemistry, University of Western Ontario, London, Ontario, N6A 5C1, Canada
| | | | - Peter K Rogan
- Department of Computer Science, University of Western Ontario, London, Ontario, N6A 5B7, Canada ; Department of Biochemistry, University of Western Ontario, London, Ontario, N6A 5C1, Canada ; Cytognomix, Inc., London, Ontario, N6G 4X8, Canada
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24
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Abstract
Interpretation of variants present in complete genomes or exomes reveals numerous sequence changes, only a fraction of which are likely to be pathogenic. Mutations have been traditionally inferred from allele frequencies and inheritance patterns in such data. Variants predicted to alter mRNA splicing can be validated by manual inspection of transcriptome sequencing data, however this approach is intractable for large datasets. These abnormal mRNA splicing patterns are characterized by reads demonstrating either exon skipping, cryptic splice site use, and high levels of intron inclusion, or combinations of these properties. We present, Veridical, an in silico method for the automatic validation of DNA sequencing variants that alter mRNA splicing. Veridical performs statistically valid comparisons of the normalized read counts of abnormal RNA species in mutant versus non-mutant tissues. This leverages large numbers of control samples to corroborate the consequences of predicted splicing variants in complete genomes and exomes.
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Affiliation(s)
- Coby Viner
- Department of Computer Science, University of Western Ontario, London, Ontario, N6A 5B7, Canada
| | - Stephanie N Dorman
- Department of Biochemistry, University of Western Ontario, London, Ontario, N6A 5C1, Canada
| | | | - Peter K Rogan
- Department of Computer Science, University of Western Ontario, London, Ontario, N6A 5B7, Canada ; Department of Biochemistry, University of Western Ontario, London, Ontario, N6A 5C1, Canada ; Cytognomix, Inc., London, Ontario, N6G 4X8, Canada
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