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Wayhelova M, Vallova V, Broz P, Mikulasova A, Smetana J, Dynkova Filkova H, Machackova D, Handzusova K, Gaillyova R, Kuglik P. Exome sequencing improves the molecular diagnostics of paediatric unexplained neurodevelopmental disorders. Orphanet J Rare Dis 2024; 19:41. [PMID: 38321498 PMCID: PMC10845791 DOI: 10.1186/s13023-024-03056-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Accepted: 01/29/2024] [Indexed: 02/08/2024] Open
Abstract
BACKGROUND Neurodevelopmental disorders (NDDs) and/or associated multiple congenital abnormalities (MCAs) represent a genetically heterogeneous group of conditions with an adverse prognosis for the quality of intellectual and social abilities and common daily functioning. The rapid development of exome sequencing (ES) techniques, together with trio-based analysis, nowadays leads to up to 50% diagnostic yield. Therefore, it is considered as the state-of-the-art approach in these diagnoses. RESULTS In our study, we present the results of ES in a cohort of 85 families with 90 children with severe NDDs and MCAs. The interconnection of the in-house bioinformatic pipeline and a unique algorithm for variant prioritization resulted in a diagnostic yield of up to 48.9% (44/90), including rare and novel causative variants (41/90) and intragenic copy-number variations (CNVs) (3/90). Of the total number of 47 causative variants, 53.2% (25/47) were novel, highlighting the clinical benefit of ES for unexplained NDDs. Moreover, trio-based ES was verified as a reliable tool for the detection of rare CNVs, ranging from intragenic exon deletions (GRIN2A, ZC4H2 genes) to a 6-Mb duplication. The functional analysis using PANTHER Gene Ontology confirmed the involvement of genes with causative variants in a wide spectrum of developmental processes and molecular pathways, which form essential structural and functional components of the central nervous system. CONCLUSION Taken together, we present one of the first ES studies of this scale from the central European region. Based on the high diagnostic yield for paediatric NDDs in this study, 48.9%, we confirm trio-based ES as an effective and reliable first-tier diagnostic test in the genetic evaluation of children with NDDs.
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Affiliation(s)
- Marketa Wayhelova
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic.
- Centre of Molecular Biology and Genetics, University Hospital Brno, Brno, Czech Republic.
| | - Vladimira Vallova
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
- Centre of Molecular Biology and Genetics, University Hospital Brno, Brno, Czech Republic
| | - Petr Broz
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
- Department of Biology and Medical Genetics, 2nd Faculty of Medicine, Charles University Prague and University Hospital Motol, Prague, Czech Republic
| | - Aneta Mikulasova
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle Upon Tyne, UK
| | - Jan Smetana
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Hana Dynkova Filkova
- Centre of Molecular Biology and Genetics, University Hospital Brno, Brno, Czech Republic
| | - Dominika Machackova
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Kristina Handzusova
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Renata Gaillyova
- Department of Medical Genetics and Genomics, University Hospital Brno, Brno, Czech Republic
| | - Petr Kuglik
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
- Centre of Molecular Biology and Genetics, University Hospital Brno, Brno, Czech Republic
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Sun KY, Bai X, Chen S, Bao S, Kapoor M, Zhang C, Backman J, Joseph T, Maxwell E, Mitra G, Gorovits A, Mansfield A, Boutkov B, Gokhale S, Habegger L, Marcketta A, Locke A, Kessler MD, Sharma D, Staples J, Bovijn J, Gelfman S, Gioia AD, Rajagopal V, Lopez A, Varela JR, Alegre J, Berumen J, Tapia-Conyer R, Kuri-Morales P, Torres J, Emberson J, Collins R, Cantor M, Thornton T, Kang HM, Overton J, Shuldiner AR, Cremona ML, Nafde M, Baras A, Abecasis G, Marchini J, Reid JG, Salerno W, Balasubramanian S. A deep catalog of protein-coding variation in 985,830 individuals. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.09.539329. [PMID: 37214792 PMCID: PMC10197621 DOI: 10.1101/2023.05.09.539329] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Coding variants that have significant impact on function can provide insights into the biology of a gene but are typically rare in the population. Identifying and ascertaining the frequency of such rare variants requires very large sample sizes. Here, we present the largest catalog of human protein-coding variation to date, derived from exome sequencing of 985,830 individuals of diverse ancestry to serve as a rich resource for studying rare coding variants. Individuals of African, Admixed American, East Asian, Middle Eastern, and South Asian ancestry account for 20% of this Exome dataset. Our catalog of variants includes approximately 10.5 million missense (54% novel) and 1.1 million predicted loss-of-function (pLOF) variants (65% novel, 53% observed only once). We identified individuals with rare homozygous pLOF variants in 4,874 genes, and for 1,838 of these this work is the first to document at least one pLOF homozygote. Additional insights from the RGC-ME dataset include 1) improved estimates of selection against heterozygous loss-of-function and identification of 3,459 genes intolerant to loss-of-function, 83 of which were previously assessed as tolerant to loss-of-function and 1,241 that lack disease annotations; 2) identification of regions depleted of missense variation in 457 genes that are tolerant to loss-of-function; 3) functional interpretation for 10,708 variants of unknown or conflicting significance reported in ClinVar as cryptic splice sites using splicing score thresholds based on empirical variant deleteriousness scores derived from RGC-ME; and 4) an observation that approximately 3% of sequenced individuals carry a clinically actionable genetic variant in the ACMG SF 3.1 list of genes. We make this important resource of coding variation available to the public through a variant allele frequency browser. We anticipate that this report and the RGC-ME dataset will serve as a valuable reference for understanding rare coding variation and help advance precision medicine efforts.
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Affiliation(s)
| | | | - Siying Chen
- Regeneron Genetics Center, Tarrytown, NY, USA
| | - Suying Bao
- Regeneron Genetics Center, Tarrytown, NY, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | - Adam Locke
- Regeneron Genetics Center, Tarrytown, NY, USA
| | | | | | | | | | | | | | | | | | | | - Jesus Alegre
- Experimental Research Unit from the Faculty of Medicine (UIME), National Autonomous University of Mexico (UNAM)
| | - Jaime Berumen
- Experimental Research Unit from the Faculty of Medicine (UIME), National Autonomous University of Mexico (UNAM)
| | - Roberto Tapia-Conyer
- Experimental Research Unit from the Faculty of Medicine (UIME), National Autonomous University of Mexico (UNAM)
| | - Pablo Kuri-Morales
- Experimental Research Unit from the Faculty of Medicine (UIME), National Autonomous University of Mexico (UNAM)
| | - Jason Torres
- Clinical Trial Service Unit & Epidemiological Studies Unit, Nuffield Department of Population Health, University of Oxford, Oxford, UK
| | - Jonathan Emberson
- Clinical Trial Service Unit & Epidemiological Studies Unit, Nuffield Department of Population Health, University of Oxford, Oxford, UK
- MRC Population Health Research Unit, Nuffield Department of Population Health, University of Oxford, Oxford, UK
| | - Rory Collins
- Clinical Trial Service Unit & Epidemiological Studies Unit, Nuffield Department of Population Health, University of Oxford, Oxford, UK
| | | | | | | | | | | | | | | | | | - Mona Nafde
- Regeneron Genetics Center, Tarrytown, NY, USA
| | - Aris Baras
- Regeneron Genetics Center, Tarrytown, NY, USA
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Avnat E, Shapira G, Shoval S, Israel-Elgali I, Alkelai A, Shuldiner AR, Gonzaga-Jauregui C, Zidan J, Maray T, Shomron N, Friedman E. Comprehensive Genetic Analysis of Druze Provides Insights into Carrier Screening. Genes (Basel) 2023; 14:genes14040937. [PMID: 37107695 PMCID: PMC10137689 DOI: 10.3390/genes14040937] [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: 02/18/2023] [Revised: 03/24/2023] [Accepted: 04/14/2023] [Indexed: 04/29/2023] Open
Abstract
BACKGROUND Druze individuals, like many genetically homogeneous and isolated populations, harbor recurring pathogenic variants (PV) in autosomal recessive (AR) disorders. METHODS Variant calling of whole-genome sequencing (WGS) of 40 Druze from the Human Genome Diversity Project (HGDP) was performed (HGDP-cohort). Additionally, we performed whole exome sequencing (WES) of 118 Druze individuals: 38 trios and 2 couples, representing geographically distinct clans (WES-cohort). Rates of validated PV were compared with rates in worldwide and Middle Eastern populations, from the gnomAD and dbSNP datasets. RESULTS Overall, 34 PVs were identified: 30 PVs in genes underlying AR disorders, 3 additional PVs were associated with autosomal dominant (AD) disorders, and 1 PV with X-linked-dominant inherited disorder in the WES cohort. CONCLUSIONS The newly identified PVs associated with AR conditions should be considered for incorporation into prenatal-screening options offered to Druze individuals after an extension and validation of the results in a larger study.
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Affiliation(s)
- Eden Avnat
- Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Guy Shapira
- Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
- Edmond J. Safra Center for Bioinformatics, Tel Aviv University, Tel Aviv 69978, Israel
| | - Shelly Shoval
- The Susanne Levy Gertner Oncogenetics Unit, Institute of Human Genetics, Sheba Medical Center, Ramat Gan 52621, Israel
| | - Ifat Israel-Elgali
- Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
- Sagol School of Neuroscience, Tel-Aviv University, Tel Aviv 69978, Israel
| | - Anna Alkelai
- Regeneron Genetics Center, Tarrytown, NY 10591, USA
| | | | - Claudia Gonzaga-Jauregui
- Regeneron Genetics Center, Tarrytown, NY 10591, USA
- International Laboratory for Human Genome Research, Laboratorio Internacional de Investigación sobre el Genoma Humano, Universidad Nacional Autónoma de México, Juriquilla 04510, Querétaro, Mexico
| | - Jamal Zidan
- The Oncology Department, Ziv Medical Center, and the Azrieli Faculty of Medicine, Bar-Ilan University, Zefat 13206, Israel
| | - Taiseer Maray
- Golan for Development, Majdal Shams 1243800, Golan Heights
| | - Noam Shomron
- Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
- Edmond J. Safra Center for Bioinformatics, Tel Aviv University, Tel Aviv 69978, Israel
- Sagol School of Neuroscience, Tel-Aviv University, Tel Aviv 69978, Israel
| | - Eitan Friedman
- Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
- The Meirav High Risk Clinic, Chaim Sheba Medical Center, Tel-Hashomer, Ramat Gan 52621, Israel
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