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Johansson J, Lidéus S, Frykholm C, Gunnarsson C, Mihalic F, Gudmundsson S, Ekvall S, Molin AM, Pham M, Vihinen M, Lagerstedt-Robinson K, Nordgren A, Jemth P, Ameur A, Annerén G, Wilbe M, Bondeson ML. Gustavson syndrome is caused by an in-frame deletion in RBMX associated with potentially disturbed SH3 domain interactions. Eur J Hum Genet 2024; 32:333-341. [PMID: 37277488 PMCID: PMC10923852 DOI: 10.1038/s41431-023-01392-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Revised: 03/07/2023] [Accepted: 05/12/2023] [Indexed: 06/07/2023] Open
Abstract
RNA binding motif protein X-linked (RBMX) encodes the heterogeneous nuclear ribonucleoprotein G (hnRNP G) that regulates splicing, sister chromatid cohesion and genome stability. RBMX knock down experiments in various model organisms highlight the gene's importance for brain development. Deletion of the RGG/RG motif in hnRNP G has previously been associated with Shashi syndrome, however involvement of other hnRNP G domains in intellectual disability remain unknown. In the current study, we present the underlying genetic and molecular cause of Gustavson syndrome. Gustavson syndrome was first reported in 1993 in a large Swedish five-generation family presented with profound X-linked intellectual disability and an early death. Extensive genomic analyses of the family revealed hemizygosity for a novel in-frame deletion in RBMX in affected individuals (NM_002139.4; c.484_486del, p.(Pro162del)). Carrier females were asymptomatic and presented with skewed X-chromosome inactivation, indicating silencing of the pathogenic allele. Affected individuals presented minor phenotypic overlap with Shashi syndrome, indicating a different disease-causing mechanism. Investigation of the variant effect in a neuronal cell line (SH-SY5Y) revealed differentially expressed genes enriched for transcription factors involved in RNA polymerase II transcription. Prediction tools and a fluorescence polarization assay imply a novel SH3-binding motif of hnRNP G, and potentially a reduced affinity to SH3 domains caused by the deletion. In conclusion, we present a novel in-frame deletion in RBMX segregating with Gustavson syndrome, leading to disturbed RNA polymerase II transcription, and potentially reduced SH3 binding. The results indicate that disruption of different protein domains affects the severity of RBMX-associated intellectual disabilities.
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Affiliation(s)
- Josefin Johansson
- Department of Immunology, Genetics and Pathology, Biomedical Centre, Uppsala University, Uppsala, Sweden
| | - Sarah Lidéus
- Department of Immunology, Genetics and Pathology, Biomedical Centre, Uppsala University, Uppsala, Sweden
| | - Carina Frykholm
- Department of Immunology, Genetics and Pathology, Biomedical Centre, Uppsala University, Uppsala, Sweden
| | - Cecilia Gunnarsson
- Department of Clinical Genetics, and Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
- Centre for Rare Diseases in South East Region of Sweden, Linköping University, Linköping, Sweden
| | - Filip Mihalic
- Department of Medical Biochemistry and Microbiology, Uppsala University, Box 582, Husargatan 3, 751 23, Uppsala, Sweden
| | - Sanna Gudmundsson
- Department of Immunology, Genetics and Pathology, Biomedical Centre, Uppsala University, Uppsala, Sweden
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, USA
| | - Sara Ekvall
- Department of Immunology, Genetics and Pathology, Biomedical Centre, Uppsala University, Uppsala, Sweden
| | - Anna-Maja Molin
- Department of Immunology, Genetics and Pathology, Biomedical Centre, Uppsala University, Uppsala, Sweden
| | - Mai Pham
- Department of Immunology, Genetics and Pathology, Biomedical Centre, Uppsala University, Uppsala, Sweden
| | - Mauno Vihinen
- Department of Experimental Medical Science, BMC B13, Lund University, SE-22 184, Lund, Sweden
| | - Kristina Lagerstedt-Robinson
- Clinical Genetics, Karolinska University Hospital, Solna, Sweden
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Ann Nordgren
- Clinical Genetics, Karolinska University Hospital, Solna, Sweden
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
- Department of Clinical Genetics and Genomics, Sahlgrenska University Hospital, Gothenburg, Sweden
- Institute of Biomedicine, Department of Laboratory Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Per Jemth
- Department of Medical Biochemistry and Microbiology, Uppsala University, Box 582, Husargatan 3, 751 23, Uppsala, Sweden
| | - Adam Ameur
- Department of Immunology, Genetics and Pathology, Biomedical Centre, Uppsala University, Uppsala, Sweden
| | - Göran Annerén
- Department of Immunology, Genetics and Pathology, Biomedical Centre, Uppsala University, Uppsala, Sweden
| | - Maria Wilbe
- Department of Immunology, Genetics and Pathology, Biomedical Centre, Uppsala University, Uppsala, Sweden
| | - Marie-Louise Bondeson
- Department of Immunology, Genetics and Pathology, Biomedical Centre, Uppsala University, Uppsala, Sweden.
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Baliakas P, Munters AR, Kämpe A, Tesi B, Bondeson ML, Ladenvall C, Eriksson D. Integrating a Polygenic Risk Score into a clinical setting would impact risk predictions in familial breast cancer. J Med Genet 2024; 61:150-154. [PMID: 37580114 PMCID: PMC10850617 DOI: 10.1136/jmg-2023-109311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Accepted: 07/28/2023] [Indexed: 08/16/2023]
Abstract
BACKGROUND Low-impact genetic variants identified in population-based genetic studies are not routinely measured as part of clinical genetic testing in familial breast cancer (BC). We studied the consequences of integrating an established Polygenic Risk Score (PRS) (BCAC 313, PRS313) into clinical sequencing of women with familial BC in Sweden. METHODS We developed an add-on sequencing panel to capture 313 risk variants in addition to the clinical screening of hereditary BC genes. Index patients with no pathogenic variant from 87 families, and 1000 population controls, were included in comparative PRS calculations. Including detailed family history, sequencing results and tumour pathology information, we used BOADICEA (Breast and Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm) V.6 to estimate contralateral and lifetime risks without and with PRS313. RESULTS Women with BC but no pathogenic variants in hereditary BC genes have a higher PRS313 compared with population controls (mean+0.78 SD, p<3e-9). Implementing PRS313 in the clinical risk estimation before their BC diagnosis would have changed the recommended follow-up in 24%-45% of women. CONCLUSIONS Our results show the potential impact of incorporating PRS313 directly in the clinical genomic investigation of women with familial BC.
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Affiliation(s)
- Panagiotis Baliakas
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Arielle R Munters
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Anders Kämpe
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
- Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden
| | - Bianca Tesi
- Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden
- Department of Clinical Genetics, Karolinska Institutet, Stockholm, Sweden
| | - Marie-Louise Bondeson
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Claes Ladenvall
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Daniel Eriksson
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
- Department of Clinical Genetics, Akademiska Sjukhuset, Uppsala, Sweden
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Johansson J, Lidéus S, Höijer I, Ameur A, Gudmundsson S, Annerén G, Bondeson ML, Wilbe M. A novel quantitative targeted analysis of X-chromosome inactivation (XCI) using nanopore sequencing. Sci Rep 2023; 13:12856. [PMID: 37553382 PMCID: PMC10409790 DOI: 10.1038/s41598-023-34413-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 04/29/2023] [Indexed: 08/10/2023] Open
Abstract
X-chromosome inactivation (XCI) analyses often assist in diagnostics of X-linked traits, however accurate assessment remains challenging with current methods. We developed a novel strategy using amplification-free Cas9 enrichment and Oxford nanopore technologies sequencing called XCI-ONT, to investigate and rigorously quantify XCI in human androgen receptor gene (AR) and human X-linked retinitis pigmentosa 2 gene (RP2). XCI-ONT measures methylation over 116 CpGs in AR and 58 CpGs in RP2, and separate parental X-chromosomes without PCR bias. We show the usefulness of the XCI-ONT strategy over the PCR-based golden standard XCI technique that only investigates one or two CpGs per gene. The results highlight the limitations of using the golden standard technique when the XCI pattern is partially skewed and the advantages of XCI-ONT to rigorously quantify XCI. This study provides a universal XCI-method on DNA, which is highly valuable in clinical and research framework of X-linked traits.
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Affiliation(s)
- Josefin Johansson
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Husargatan 3, Box 815, SE-751 08, Uppsala, Sweden
| | - Sarah Lidéus
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Husargatan 3, Box 815, SE-751 08, Uppsala, Sweden
| | - Ida Höijer
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Husargatan 3, Box 815, SE-751 08, Uppsala, Sweden
| | - Adam Ameur
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Husargatan 3, Box 815, SE-751 08, Uppsala, Sweden
| | - Sanna Gudmundsson
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Division of Genetics and Genomics, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Göran Annerén
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Husargatan 3, Box 815, SE-751 08, Uppsala, Sweden
| | - Marie-Louise Bondeson
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Husargatan 3, Box 815, SE-751 08, Uppsala, Sweden
| | - Maria Wilbe
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Husargatan 3, Box 815, SE-751 08, Uppsala, Sweden.
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Höijer I, Johansson J, Gudmundsson S, Chin CS, Bunikis I, Häggqvist S, Emmanouilidou A, Wilbe M, den Hoed M, Bondeson ML, Feuk L, Gyllensten U, Ameur A. Amplification-free long-read sequencing reveals unforeseen CRISPR-Cas9 off-target activity. Genome Biol 2020; 21:290. [PMID: 33261648 PMCID: PMC7706270 DOI: 10.1186/s13059-020-02206-w] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 11/17/2020] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND One ongoing concern about CRISPR-Cas9 genome editing is that unspecific guide RNA (gRNA) binding may induce off-target mutations. However, accurate prediction of CRISPR-Cas9 off-target activity is challenging. Here, we present SMRT-OTS and Nano-OTS, two novel, amplification-free, long-read sequencing protocols for detection of gRNA-driven digestion of genomic DNA by Cas9 in vitro. RESULTS The methods are assessed using the human cell line HEK293, re-sequenced at 18x coverage using highly accurate HiFi SMRT reads. SMRT-OTS and Nano-OTS are first applied to three different gRNAs targeting HEK293 genomic DNA, resulting in a set of 55 high-confidence gRNA cleavage sites identified by both methods. Twenty-five of these sites are not reported by off-target prediction software, either because they contain four or more single nucleotide mismatches or insertion/deletion mismatches, as compared with the human reference. Additional experiments reveal that 85% of Cas9 cleavage sites are also found by other in vitro-based methods and that on- and off-target sites are detectable in gene bodies where short-reads fail to uniquely align. Even though SMRT-OTS and Nano-OTS identify several sites with previously validated off-target editing activity in cells, our own CRISPR-Cas9 editing experiments in human fibroblasts do not give rise to detectable off-target mutations at the in vitro-predicted sites. However, indel and structural variation events are enriched at the on-target sites. CONCLUSIONS Amplification-free long-read sequencing reveals Cas9 cleavage sites in vitro that would have been difficult to predict using computational tools, including in dark genomic regions inaccessible by short-read sequencing.
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Affiliation(s)
- Ida Höijer
- Science for Life Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Josefin Johansson
- Science for Life Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Sanna Gudmundsson
- Science for Life Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
- Program in Medical and Population Genetics, Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA USA
- Division of Genetics and Genomics, Boston Children’s Hospital, Boston, MA USA
| | | | - Ignas Bunikis
- Science for Life Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Susana Häggqvist
- Science for Life Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Anastasia Emmanouilidou
- Science for Life Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
- The Beijer laboratory and Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Maria Wilbe
- Science for Life Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Marcel den Hoed
- Science for Life Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
- The Beijer laboratory and Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Marie-Louise Bondeson
- Science for Life Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Lars Feuk
- Science for Life Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Ulf Gyllensten
- Science for Life Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Adam Ameur
- Science for Life Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
- Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia
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Körberg I, Nowinski D, Bondeson ML, Melin M, Kölby L, Stattin EL. A progressive and complex clinical course in two family members with ERF-related craniosynostosis: a case report. BMC Med Genet 2020; 21:90. [PMID: 32370745 PMCID: PMC7201657 DOI: 10.1186/s12881-020-01015-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 03/29/2020] [Indexed: 01/08/2023]
Abstract
Background ERF-related craniosynostosis are a rare, complex, premature trisutural fusion associated with a broad spectrum of clinical features and heterogeneous aetiology. Here we describe two cases with the same pathogenic variant and a detailed description of their clinical course. Case presentation Two subjects; a boy with a BLSS requiring repeated skull expansions and his mother who had been operated once for sagittal synostosis. Both developed intracranial hypertension at some point during the course, which was for both verified by formal invasive intracranial pressure monitoring. Exome sequencing revealed a pathogenic truncating frame shift variant in the ERF gene. Conclusions Here we describe a boy and his mother with different craniosynostosis patterns, but both with verified intracranial hypertension and heterozygosity for a truncating variant of ERF c.1201_1202delAA (p.Lys401Glufs*10). Our work provides supplementary evidence in support of previous phenotypic descriptions of ERF-related craniosynostosis, particularly late presentation, an evolving synostotic pattern and variable expressivity even among affected family members.
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Affiliation(s)
- Izabella Körberg
- Department of Immunology, Genetics and Pathology, Uppsala University, Science for Life Laboratory, Uppsala, Sweden.
| | - Daniel Nowinski
- Department of Surgical Sciences, Plastic Surgery, Uppsala University, Uppsala, Sweden
| | - Marie-Louise Bondeson
- Department of Immunology, Genetics and Pathology, Uppsala University, Science for Life Laboratory, Uppsala, Sweden
| | - Malin Melin
- Department of Immunology, Genetics and Pathology, Uppsala University, Science for Life Laboratory, Uppsala, Sweden
| | - Lars Kölby
- Department of Plastic Surgery, Institute for Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Eva-Lena Stattin
- Department of Immunology, Genetics and Pathology, Uppsala University, Science for Life Laboratory, Uppsala, Sweden
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Gudmundsson S, Wilbe M, Filipek-Górniok B, Molin AM, Ekvall S, Johansson J, Allalou A, Gylje H, Kalscheuer VM, Ledin J, Annerén G, Bondeson ML. TAF1, associated with intellectual disability in humans, is essential for embryogenesis and regulates neurodevelopmental processes in zebrafish. Sci Rep 2019; 9:10730. [PMID: 31341187 PMCID: PMC6656882 DOI: 10.1038/s41598-019-46632-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 07/01/2019] [Indexed: 11/22/2022] Open
Abstract
The TATA-box binding protein associated factor 1 (TAF1) protein is a key unit of the transcription factor II D complex that serves a vital function during transcription initiation. Variants of TAF1 have been associated with neurodevelopmental disorders, but TAF1's molecular functions remain elusive. In this study, we present a five-generation family affected with X-linked intellectual disability that co-segregated with a TAF1 c.3568C>T, p.(Arg1190Cys) variant. All affected males presented with intellectual disability and dysmorphic features, while heterozygous females were asymptomatic and had completely skewed X-chromosome inactivation. We investigated the role of TAF1 and its association to neurodevelopment by creating the first complete knockout model of the TAF1 orthologue in zebrafish. A crucial function of human TAF1 during embryogenesis can be inferred from the model, demonstrating that intact taf1 is essential for embryonic development. Transcriptome analysis of taf1 zebrafish knockout revealed enrichment for genes associated with neurodevelopmental processes. In conclusion, we propose that functional TAF1 is essential for embryonic development and specifically neurodevelopmental processes.
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Affiliation(s)
- Sanna Gudmundsson
- Department of Immunology, Genetics and Pathology, Uppsala University, Science for Life Laboratory, Uppsala, 751 08, Sweden.
| | - Maria Wilbe
- Department of Immunology, Genetics and Pathology, Uppsala University, Science for Life Laboratory, Uppsala, 751 08, Sweden
| | - Beata Filipek-Górniok
- Department of Organismal Biology, Genome Engineering Zebrafish, Science for Life Laboratory, Uppsala University, Uppsala, 752 36, Sweden
| | - Anna-Maja Molin
- Department of Immunology, Genetics and Pathology, Uppsala University, Science for Life Laboratory, Uppsala, 751 08, Sweden
| | - Sara Ekvall
- Department of Immunology, Genetics and Pathology, Uppsala University, Science for Life Laboratory, Uppsala, 751 08, Sweden
| | - Josefin Johansson
- Department of Immunology, Genetics and Pathology, Uppsala University, Science for Life Laboratory, Uppsala, 751 08, Sweden
| | - Amin Allalou
- Department of Information Technology, Uppsala University, Sweden and Science for Life Laboratory, Uppsala, 751 05, Sweden
| | - Hans Gylje
- Department of Paediatrics, Central Hospital, Västerås, 721 89, Sweden
| | - Vera M Kalscheuer
- Research Group Development and Disease, Max Planck Institute for Molecular Genetics, Berlin, 141 95, Germany
| | - Johan Ledin
- Department of Organismal Biology, Genome Engineering Zebrafish, Science for Life Laboratory, Uppsala University, Uppsala, 752 36, Sweden
| | - Göran Annerén
- Department of Immunology, Genetics and Pathology, Uppsala University, Science for Life Laboratory, Uppsala, 751 08, Sweden.
| | - Marie-Louise Bondeson
- Department of Immunology, Genetics and Pathology, Uppsala University, Science for Life Laboratory, Uppsala, 751 08, Sweden.
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Gudmundsson S, Annerén G, Marcos-Alcalde Í, Wilbe M, Melin M, Gómez-Puertas P, Bondeson ML. A novel RAD21 p.(Gln592del) variant expands the clinical description of Cornelia de Lange syndrome type 4 - Review of the literature. Eur J Med Genet 2018; 62:103526. [PMID: 30125677 DOI: 10.1016/j.ejmg.2018.08.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 08/14/2018] [Accepted: 08/15/2018] [Indexed: 11/18/2022]
Abstract
Cornelia de Lange syndrome (CdLS) is a heterogeneous developmental disorder where 70% of clinically diagnosed patients harbor a variant in one of five CdLS associated cohesin proteins. Around 500 variants have been identified to cause CdLS, however only eight different alterations have been identified in the RAD21 gene, encoding the RAD21 cohesin complex component protein that constitute the link between SMC1A and SMC3 within the cohesin ring. We report a 15-month-old boy presenting with developmental delay, distinct CdLS-like facial features, gastrointestinal reflux in early infancy, testis retention, prominent digit pads and diaphragmatic hernia. Exome sequencing revealed a novel RAD21 variant, c.1774_1776del, p.(Gln592del), suggestive of CdLS type 4. Segregation analysis of the two healthy parents confirmed the variant as de novo and bioinformatic analysis predicted the variant as disease-causing. Assessment by in silico structural model predicted that the p.Gln592del variant results in a discontinued contact between RAD21-Lys591 and the SMC1A residues Glu1191 and Glu1192, causing changes in the RAD21-SMC1A interface. In conclusion, we report a patient that expands the clinical description of CdLS type 4 and presents with a novel RAD21 p.(Glu592del) variant that causes a disturbed RAD21-SMC1A interface according to in silco structural modeling.
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Affiliation(s)
- Sanna Gudmundsson
- Department of Immunology, Genetics and Pathology, Uppsala University, Science for Life Laboratory, 75108, Uppsala, Sweden.
| | - Göran Annerén
- Department of Immunology, Genetics and Pathology, Uppsala University, Science for Life Laboratory, 75108, Uppsala, Sweden
| | - Íñigo Marcos-Alcalde
- Centro de Biología Molecular "Severo Ochoa" (CSIC-UAM), 28049, Madrid, Spain; Faculty of Experimental Sciences, Francisco de Vitoria University, Pozuelo de Alarcón, 28223, Madrid, Spain
| | - Maria Wilbe
- Department of Immunology, Genetics and Pathology, Uppsala University, Science for Life Laboratory, 75108, Uppsala, Sweden
| | - Malin Melin
- Department of Immunology, Genetics and Pathology, Uppsala University, Science for Life Laboratory, 75108, Uppsala, Sweden
| | | | - Marie-Louise Bondeson
- Department of Immunology, Genetics and Pathology, Uppsala University, Science for Life Laboratory, 75108, Uppsala, Sweden.
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Stattin EL, Johansson J, Gudmundsson S, Ameur A, Lundberg S, Bondeson ML, Wilbe M. A novel ECEL1 mutation expands the phenotype of distal arthrogryposis multiplex congenita type 5D to include pretibial vertical skin creases. Am J Med Genet A 2018; 176:1405-1410. [PMID: 29663639 DOI: 10.1002/ajmg.a.38691] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 02/20/2018] [Accepted: 03/11/2018] [Indexed: 12/11/2022]
Abstract
Arthrogryposis multiplex congenita (AMC) is a heterogeneous disorder characterized by multiple joint contractures often in association with other congenital abnormalities. Pretibial linear vertical creases are a rare finding associated with arthrogryposis, and the etiology of the specific condition is unknown. We aimed to genetically and clinically characterize a boy from a consanguineous family, presenting with AMC and pretibial vertical linear creases on the shins. Whole exome sequencing and variant analysis revealed homozygous novel missense variants of ECEL1 (c.1163T > C, p.Leu388Pro, NM_004826) and MUSK (c.2572C > T, p.Arg858Cys, NM_005592). Both variants are predicted to have deleterious effects on the protein function, with amino acid positions highly conserved among species. The variants segregated in the family, with healthy mother, father, and sister being heterozygous carriers and the index patient being homozygous for both mutations. We report on a unique patient with a novel ECEL1 homozygous mutation, expanding the phenotypic spectrum of Distal AMC Type 5D to include vertical linear skin creases. The homozygous mutation in MUSK is of unknown clinical significance. MUSK mutations have previously shown to cause congenital myasthenic syndrome, a neuromuscular disorder with defects in the neuromuscular junction.
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Affiliation(s)
- Eva-Lena Stattin
- Science for Life Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Josefin Johansson
- Science for Life Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Sanna Gudmundsson
- Science for Life Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Adam Ameur
- Science for Life Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Staffan Lundberg
- Department of Women's and Children's Health, Uppsala University, Uppsala, Sweden
| | - Marie-Louise Bondeson
- Science for Life Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Maria Wilbe
- Science for Life Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
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Olsson KS, Wålinder O, Jansson U, Wilbe M, Bondeson ML, Stattin EL, Raha-Chowdhury R, Williams R. Common founder effects of hereditary hemochromatosis, Wilson´s disease, the long QT syndrome and autosomal recessive deafness caused by two novel mutations in the WHRN and TMC1 genes. Hereditas 2017; 154:16. [PMID: 29270100 PMCID: PMC5735936 DOI: 10.1186/s41065-017-0052-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Accepted: 11/19/2017] [Indexed: 11/22/2022] Open
Abstract
Background Genealogy and molecular genetic studies of a Swedish river valley population resulted in a large pedigree, showing that the hereditary hemochromatosis (HH) HFE/p.C282Y mutation is inherited with other recessive disorders such as Wilson´s disease (WND), a rare recessive disorder of copper overload. The population also contain individuals with the Swedish long QT syndrome (LQTS1) founder mutation (KCNQ1/p.Y111C) which in homozygotes causes the Jervell & Lange Nielsen syndrome (JLNS) and hearing loss (HL). Aims of the study were to test whether the Swedish long QT founder mutation originated in an ancestral HFE family and if carriers had an increased risk for hemochromatosis (HH), a treatable disorder. We also aimed to identify the pathogenic mutation causing the hearing loss disorder segregating in the pedigree. Methods LQTS patients were asked about their ancestry and possible origin in a HH family. They were also offered a predictive testing for the HFE genotype. Church books were screened for families with hearing loss. One HH family had two members with hearing loss, who underwent molecular genetic analysis of the LQTS founder mutation, connexin 26 and thereafter exome sequencing. Another family with hearing loss in repeat generations was also analyzed for connexin 26 and underwent exome sequencing. Results Of nine LQTS patients studied, four carried a HFE mutation (two p.C282Y, two p.H63D), none was homozygous. Three LQTS patients confirmed origin in a female founder ( b 1694, identical to AJ b 1694, a HFE pedigree member from the Fax river. Her descent of 44 HH families, included also 29 families with hearing loss (HL) suggesting JLNS. Eleven LQTS probands confirmed origin in a second founder couple (b 1614/1605) in which the woman b 1605 was identical to a HFE pedigree member from the Fjällsjö river. In her descent there were not only 64 HH, six WND families, one JLNS, but also 48 hearing loss families. Most hearing loss was non syndromic and caused by founder effects of the late 16th century. One was of Swedish origin carrying the WHRN, c.1977delC, (p.S660Afs*30) mutation, the other was a TMC1(NM_138691),c.1814T>C,(p.L605P) mutation, possibly of Finnish origin. Conclusions Deep human HFE genealogies show HFE to be associated with other genetic disorders like Wilson´s disease, LQTS, JLNS, and autosomal recessive hearing loss. Two new homozygous HL mutations in WHRN/p.S660Afs*30 and TMC1/p.L605P were identified,none of them previously reported from Scandinavia. The rarity of JLNS was possibly caused by miscarriage or intrauterine death. Most hearing loss (81.7%) was seen after 1844 when first cousin marriages were permitted. However, only 10 (10.3%) came from 1st cousin unions and only 2 (2.0 %) was born out of wedlock. Electronic supplementary material The online version of this article (10.1186/s41065-017-0052-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- K Sigvard Olsson
- Section of Hematology and Coagulation, Department of Medicine, Sahlgrenska Academy, University of Göteborg, S 413 45 Göteborg, Sweden
| | - Olof Wålinder
- Department of Medicine, Östersund Hospital, Östersund, Sweden
| | - Ulf Jansson
- Department of Clinical Chemistry, Sundsvall Hospital, Sundsvall, Sweden
| | - Maria Wilbe
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Marie-Louise Bondeson
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Eva-Lena Stattin
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Ruma Raha-Chowdhury
- John van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Roger Williams
- Institute of Hepatology London, Foundation for Liver Research, London,SE5 9NT and Faculty of Life Sciences & Medicine, King´s College London, London, UK
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Wilbe M, Gudmundsson S, Johansson J, Ameur A, Stattin EL, Annerén G, Malmgren H, Frykholm C, Bondeson ML. A novel approach using long-read sequencing and ddPCR to investigate gonadal mosaicism and estimate recurrence risk in two families with developmental disorders. Prenat Diagn 2017; 37:1146-1154. [PMID: 28921562 PMCID: PMC5725701 DOI: 10.1002/pd.5156] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 09/04/2017] [Accepted: 09/06/2017] [Indexed: 12/17/2022]
Abstract
Objective De novo mutations contribute significantly to severe early‐onset genetic disorders. Even if the mutation is apparently de novo, there is a recurrence risk due to parental germ line mosaicism, depending on in which gonadal generation the mutation occurred. Methods We demonstrate the power of using SMRT sequencing and ddPCR to determine parental origin and allele frequencies of de novo mutations in germ cells in two families whom had undergone assisted reproduction. Results In the first family, a TCOF1 variant c.3156C>T was identified in the proband with Treacher Collins syndrome. The variant affects splicing and was determined to be of paternal origin. It was present in <1% of the paternal germ cells, suggesting a very low recurrence risk. In the second family, the couple had undergone several unsuccessful pregnancies where a de novo mutation PTPN11 c.923A>C causing Noonan syndrome was identified. The variant was present in 40% of the paternal germ cells suggesting a high recurrence risk. Conclusions Our findings highlight a successful strategy to identify the parental origin of mutations and to investigate the recurrence risk in couples that have undergone assisted reproduction with an unknown donor or in couples with gonadal mosaicism that will undergo preimplantation genetic diagnosis. What's already known about this topic?
De novo mutations contribute significantly to severe early‐onset genetic disorders.
what does this study add?
A novel successful strategy to identify the parental origin of de novo mutations and to investigate the recurrence risk by SMRT sequencing and ddPCR.
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Affiliation(s)
- Maria Wilbe
- Department of Immunology, Genetics, and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Sanna Gudmundsson
- Department of Immunology, Genetics, and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Josefin Johansson
- Department of Immunology, Genetics, and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Adam Ameur
- Department of Immunology, Genetics, and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Eva-Lena Stattin
- Department of Immunology, Genetics, and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Göran Annerén
- Department of Immunology, Genetics, and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Helena Malmgren
- Department of Molecular Medicine and Surgery, Karolinska Institute, Stockholm, Sweden
| | - Carina Frykholm
- Department of Immunology, Genetics, and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Marie-Louise Bondeson
- Department of Immunology, Genetics, and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
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12
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Gudmundsson S, Wilbe M, Ekvall S, Ameur A, Cahill N, Alexandrov LB, Virtanen M, Hellström Pigg M, Vahlquist A, Törmä H, Bondeson ML. Revertant mosaicism repairs skin lesions in a patient with keratitis-ichthyosis-deafness syndrome by second-site mutations in connexin 26. Hum Mol Genet 2017; 26:1070-1077. [PMID: 28158657 PMCID: PMC5409067 DOI: 10.1093/hmg/ddx017] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 12/30/2016] [Indexed: 01/21/2023] Open
Abstract
Revertant mosaicism (RM) is a naturally occurring phenomenon where the pathogenic effect of a germline mutation is corrected by a second somatic event. Development of healthy-looking skin due to RM has been observed in patients with various inherited skin disorders, but not in connexin-related disease. We aimed to clarify the underlying molecular mechanisms of suspected RM in the skin of a patient with keratitis-ichthyosis-deafness (KID) syndrome. The patient was diagnosed with KID syndrome due to characteristic skin lesions, hearing deficiency and keratitis. Investigation of GJB2 encoding connexin (Cx) 26 revealed heterozygosity for the recurrent de novo germline mutation, c.148G > A, p.Asp50Asn. At age 20, the patient developed spots of healthy-looking skin that grew in size and number within widespread erythrokeratodermic lesions. Ultra-deep sequencing of two healthy-looking skin biopsies identified five somatic nonsynonymous mutations, independently present in cis with the p.Asp50Asn mutation. Functional studies of Cx26 in HeLa cells revealed co-expression of Cx26-Asp50Asn and wild-type Cx26 in gap junction channel plaques. However, Cx26-Asp50Asn with the second-site mutations identified in the patient displayed no formation of gap junction channel plaques. We argue that the second-site mutations independently inhibit Cx26-Asp50Asn expression in gap junction channels, reverting the dominant negative effect of the p.Asp50Asn mutation. To our knowledge, this is the first time RM has been reported to result in the development of healthy-looking skin in a patient with KID syndrome.
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Affiliation(s)
- Sanna Gudmundsson
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Maria Wilbe
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Sara Ekvall
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Adam Ameur
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Nicola Cahill
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Ludmil B Alexandrov
- Theoretical Biology and Biophysics (T-6), Los Alamos National Laboratory, Los Alamos, NM, USA and
| | - Marie Virtanen
- Department of Medical Sciences, Dermatology, Uppsala University, Uppsala, Sweden
| | - Maritta Hellström Pigg
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Anders Vahlquist
- Department of Medical Sciences, Dermatology, Uppsala University, Uppsala, Sweden
| | - Hans Törmä
- Department of Medical Sciences, Dermatology, Uppsala University, Uppsala, Sweden
| | - Marie-Louise Bondeson
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
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13
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Wilbe M, Ekvall S, Eurenius K, Ericson K, Casar-Borota O, Klar J, Dahl N, Ameur A, Annerén G, Bondeson ML. MuSK: a new target for lethal fetal akinesia deformation sequence (FADS). J Med Genet 2015; 52:195-202. [PMID: 25612909 DOI: 10.1136/jmedgenet-2014-102730] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND Fetal akinesia deformation sequence syndrome (FADS, OMIM 208150) is characterised by decreased fetal movement (fetal akinesia) as well as intrauterine growth restriction, arthrogryposis, and developmental anomalies (eg, cystic hygroma, pulmonary hypoplasia, cleft palate, and cryptorchidism). Mutations in components of the acetylcholine receptor (AChR) pathway have previously been associated with FADS. METHODS AND RESULTS We report on a family with recurrent fetal loss, where the parents had five affected fetuses/children with FADS and one healthy child. The fetuses displayed no fetal movements from the gestational age of 17 weeks, extended knee joints, flexed hips and elbows, and clenched hands. Whole exome sequencing of one affected fetus and the parents was performed. A novel homozygous frameshift mutation was identified in muscle, skeletal receptor tyrosine kinase (MuSK), c.40dupA, which segregated with FADS in the family. Haplotype analysis revealed a conserved haplotype block suggesting a founder mutation. MuSK (muscle-specific tyrosine kinase receptor), a component of the AChR pathway, is a main regulator of neuromuscular junction formation and maintenance. Missense mutations in MuSK have previously been reported to cause congenital myasthenic syndrome (CMS) associated with AChR deficiency. CONCLUSIONS To our knowledge, this is the first report showing that a mutation in MuSK is associated with FADS. The results support previous findings that CMS and/or FADS are caused by complete or severe functional disruption of components located in the AChR pathway. We propose that whereas milder mutations of MuSK will cause a CMS phenotype, a complete loss is lethal and will cause FADS.
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Affiliation(s)
- Maria Wilbe
- Science for Life Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Sara Ekvall
- Science for Life Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Karin Eurenius
- Department of Women's and Children's Health, Uppsala University, Uppsala, Sweden
| | - Katharina Ericson
- Science for Life Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden Department of Pathology and Cytology, Uppsala University Hospital, Uppsala, Sweden
| | - Olivera Casar-Borota
- Science for Life Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden Department of Pathology and Cytology, Uppsala University Hospital, Uppsala, Sweden
| | - Joakim Klar
- Science for Life Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Niklas Dahl
- Science for Life Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Adam Ameur
- Science for Life Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Göran Annerén
- Science for Life Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Marie-Louise Bondeson
- Science for Life Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
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14
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Flex E, Jaiswal M, Pantaleoni F, Martinelli S, Strullu M, Fansa EK, Caye A, De Luca A, Lepri F, Dvorsky R, Pannone L, Paolacci S, Zhang SC, Fodale V, Bocchinfuso G, Rossi C, Burkitt-Wright EMM, Farrotti A, Stellacci E, Cecchetti S, Ferese R, Bottero L, Castro S, Fenneteau O, Brethon B, Sanchez M, Roberts AE, Yntema HG, Van Der Burgt I, Cianci P, Bondeson ML, Cristina Digilio M, Zampino G, Kerr B, Aoki Y, Loh ML, Palleschi A, Di Schiavi E, Carè A, Selicorni A, Dallapiccola B, Cirstea IC, Stella L, Zenker M, Gelb BD, Cavé H, Ahmadian MR, Tartaglia M. Activating mutations in RRAS underlie a phenotype within the RASopathy spectrum and contribute to leukaemogenesis. Hum Mol Genet 2014; 23:4315-27. [PMID: 24705357 PMCID: PMC4103678 DOI: 10.1093/hmg/ddu148] [Citation(s) in RCA: 105] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Accepted: 03/04/2014] [Indexed: 12/29/2022] Open
Abstract
RASopathies, a family of disorders characterized by cardiac defects, defective growth, facial dysmorphism, variable cognitive deficits and predisposition to certain malignancies, are caused by constitutional dysregulation of RAS signalling predominantly through the RAF/MEK/ERK (MAPK) cascade. We report on two germline mutations (p.Gly39dup and p.Val55Met) in RRAS, a gene encoding a small monomeric GTPase controlling cell adhesion, spreading and migration, underlying a rare (2 subjects among 504 individuals analysed) and variable phenotype with features partially overlapping Noonan syndrome, the most common RASopathy. We also identified somatic RRAS mutations (p.Gly39dup and p.Gln87Leu) in 2 of 110 cases of non-syndromic juvenile myelomonocytic leukaemia, a childhood myeloproliferative/myelodysplastic disease caused by upregulated RAS signalling, defining an atypical form of this haematological disorder rapidly progressing to acute myeloid leukaemia. Two of the three identified mutations affected known oncogenic hotspots of RAS genes and conferred variably enhanced RRAS function and stimulus-dependent MAPK activation. Expression of an RRAS mutant homolog in Caenorhabditis elegans enhanced RAS signalling and engendered protruding vulva, a phenotype previously linked to the RASopathy-causing SHOC2(S2G) mutant. Overall, these findings provide evidence of a functional link between RRAS and MAPK signalling and reveal an unpredicted role of enhanced RRAS function in human disease.
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Affiliation(s)
- Elisabetta Flex
- Dipartimento di Ematologia, Oncologia e Medicina Molecolare and
| | - Mamta Jaiswal
- Institut für Biochemie und Molekularbiologie II, Medizinische Fakultät der Heinrich-Heine Universitat, Düsseldorf 40225, Germany
| | | | | | - Marion Strullu
- Genetics Department, INSERM UMR_S940, Institut Universitaire D'Hématologie (IUH), Université Paris-Diderot Sorbonne-Paris-Cité, Paris 75010, France
| | - Eyad K Fansa
- Institut für Biochemie und Molekularbiologie II, Medizinische Fakultät der Heinrich-Heine Universitat, Düsseldorf 40225, Germany
| | - Aurélie Caye
- Genetics Department, INSERM UMR_S940, Institut Universitaire D'Hématologie (IUH), Université Paris-Diderot Sorbonne-Paris-Cité, Paris 75010, France
| | - Alessandro De Luca
- Laboratorio Mendel, Istituto di Ricovero e Cura a Carattere Scientifico-Casa Sollievo Della Sofferenza, Rome 00198, Italy
| | | | - Radovan Dvorsky
- Institut für Biochemie und Molekularbiologie II, Medizinische Fakultät der Heinrich-Heine Universitat, Düsseldorf 40225, Germany
| | - Luca Pannone
- Dipartimento di Ematologia, Oncologia e Medicina Molecolare and
| | | | - Si-Cai Zhang
- Institut für Biochemie und Molekularbiologie II, Medizinische Fakultät der Heinrich-Heine Universitat, Düsseldorf 40225, Germany
| | | | - Gianfranco Bocchinfuso
- Dipartimento di Scienze e Tecnologie Chimiche, Università 'Tor Vergata', Rome 00133, Italy
| | - Cesare Rossi
- UO Genetica Medica, Policlinico S.Orsola-Malpighi, Bologna 40138, Italy
| | - Emma M M Burkitt-Wright
- Genetic Medicine, Academic Health Science Centre, Central Manchester University Hospitals NHS Foundation Trust, Manchester M13 9WL, UK
| | - Andrea Farrotti
- Dipartimento di Scienze e Tecnologie Chimiche, Università 'Tor Vergata', Rome 00133, Italy
| | | | - Serena Cecchetti
- Dipartimento di Biologia Cellulare e Neuroscienze, Istituto Superiore di Sanità, Rome 00161, Italy
| | - Rosangela Ferese
- Laboratorio Mendel, Istituto di Ricovero e Cura a Carattere Scientifico-Casa Sollievo Della Sofferenza, Rome 00198, Italy
| | | | - Silvana Castro
- Istituto di Genetica e Biofisica 'A. Buzzati Traverso', Consiglio Nazionale Delle Ricerche, Naples 80131, Italy
| | | | - Benoît Brethon
- Pediatric Hematology Department, Robert Debré Hospital, Paris 75019, France
| | - Massimo Sanchez
- Dipartimento di Biologia Cellulare e Neuroscienze, Istituto Superiore di Sanità, Rome 00161, Italy
| | - Amy E Roberts
- Department of Cardiology and Division of Genetics, and Department of Medicine, Boston Children's Hospital, Boston, MA 02115, USA
| | - Helger G Yntema
- Department of Human Genetics, Radboud University Medical Centre, and Nijmegen Centre for Molecular Life Sciences, Radboud University, Nijmegen 6500, The Netherlands
| | - Ineke Van Der Burgt
- Department of Human Genetics, Radboud University Medical Centre, and Nijmegen Centre for Molecular Life Sciences, Radboud University, Nijmegen 6500, The Netherlands
| | - Paola Cianci
- Genetica Clinica Pediatrica, Clinica Pediatrica Università Milano Bicocca, Fondazione MBBM, A.O. S. Gerardo, Monza 20900, Italy
| | - Marie-Louise Bondeson
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala 75237, Sweden
| | | | - Giuseppe Zampino
- Istituto di Clinica Pediatrica, Università Cattolica del Sacro Cuore, Rome 00168, Italy
| | - Bronwyn Kerr
- Genetic Medicine, Academic Health Science Centre, Central Manchester University Hospitals NHS Foundation Trust, Manchester M13 9WL, UK
| | - Yoko Aoki
- Department of Medical Genetics, Tohoku University School of Medicine, Sendai 980-8574, Japan
| | - Mignon L Loh
- Department of Pediatrics, Benioff Children's Hospital, University of California School of Medicine, and the Helen Diller Family Comprehensive Cancer Center, San Francisco, CA, 94143, USA
| | - Antonio Palleschi
- Dipartimento di Scienze e Tecnologie Chimiche, Università 'Tor Vergata', Rome 00133, Italy
| | - Elia Di Schiavi
- Istituto di Genetica e Biofisica 'A. Buzzati Traverso', Consiglio Nazionale Delle Ricerche, Naples 80131, Italy
| | - Alessandra Carè
- Dipartimento di Ematologia, Oncologia e Medicina Molecolare and
| | - Angelo Selicorni
- Genetica Clinica Pediatrica, Clinica Pediatrica Università Milano Bicocca, Fondazione MBBM, A.O. S. Gerardo, Monza 20900, Italy
| | | | - Ion C Cirstea
- Institut für Biochemie und Molekularbiologie II, Medizinische Fakultät der Heinrich-Heine Universitat, Düsseldorf 40225, Germany, Leibniz Institute for Age Research, Jena 07745, Germany
| | - Lorenzo Stella
- Dipartimento di Scienze e Tecnologie Chimiche, Università 'Tor Vergata', Rome 00133, Italy
| | - Martin Zenker
- Institute of Human Genetics, University Hospital of Magdeburg, Otto-von-Guericke-University, Magdeburg 39120, Germany
| | - Bruce D Gelb
- Department of Pediatrics and Department of Genetics and Department of Genomic Sciences, Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Hélène Cavé
- Genetics Department, INSERM UMR_S940, Institut Universitaire D'Hématologie (IUH), Université Paris-Diderot Sorbonne-Paris-Cité, Paris 75010, France
| | - Mohammad R Ahmadian
- Institut für Biochemie und Molekularbiologie II, Medizinische Fakultät der Heinrich-Heine Universitat, Düsseldorf 40225, Germany
| | - Marco Tartaglia
- Dipartimento di Ematologia, Oncologia e Medicina Molecolare and
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Holmström G, Bondeson ML, Eriksson U, Åkerblom H, Larsson E. 'Congenital' nystagmus may hide various ophthalmic diagnoses. Acta Ophthalmol 2014; 92:412-6. [PMID: 23889849 DOI: 10.1111/aos.12250] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Accepted: 06/29/2013] [Indexed: 01/23/2023]
Abstract
PURPOSE To investigate whether patients registered at a low-vision centre with 'nystagmus' had any underlying, but so far unknown, ophthalmic diagnosis. METHODS All patients registered at the low-vision centre of Uppsala county with nystagmus as their major diagnosis were identified. Their medical records were studied to exclude those with other general diagnoses that could explain the nystagmus. The remaining group of patients underwent an ophthalmic examination, refraction and optical coherence tomography (OCT). Electroretinogram and genetic analyses were performed when indicated. RESULTS Sixty-two patients with nystagmus as their main diagnosis were registered at the low-vision centre, Uppsala, and 43 of them had a major diagnosis other than nystagmus. Nystagmus was the major diagnosis in 19 patients, 15 of whom, aged 6-76 years, participated in the study. Two of the patients had foveal hypoplasia and albinism, four a seemingly isolated foveal hypoplasia, three achromatopsia, one rod-cone dystrophy, one degenerative high myopia, and two could not be evaluated. Only two patients appeared to have 'congenital' nystagmus. Eleven of the patients underwent a comprehensive genetic investigation of the PAX 6 gene. In addition, four of the patients were analysed for mutations in FOXC1 and PITX2 and one in FRMD7. No mutations were found in any of the patients analysed. CONCLUSION The study illustrates that many patients in our study group with nystagmus had underlying ophthalmic diagnoses. Early diagnosis is important to facilitate habilitation and to provide genetic counselling and, in the future, possibly also gene therapy.
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Affiliation(s)
- Gerd Holmström
- Department of Neuroscience/Ophthalmology, Uppsala University, Uppsala, Sweden
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16
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Ekvall S, Sjörs K, Jonzon A, Vihinen M, Annerén G, Bondeson ML. Novel association of neurofibromatosis type 1-causing mutations in families with neurofibromatosis-Noonan syndrome. Am J Med Genet A 2013; 164A:579-87. [PMID: 24357598 DOI: 10.1002/ajmg.a.36313] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Accepted: 09/29/2013] [Indexed: 11/10/2022]
Abstract
Neurofibromatosis-Noonan syndrome (NFNS) is a rare condition with clinical features of both neurofibromatosis type 1 (NF1) and Noonan syndrome (NS). All three syndromes belong to the RASopathies, which are caused by dysregulation of the RAS-MAPK pathway. The major gene involved in NFNS is NF1, but co-occurring NF1 and PTPN11 mutations in NFNS have been reported. Knowledge about possible involvement of additional RASopathy-associated genes in NFNS is, however, very limited. We present a comprehensive clinical and molecular analysis of eight affected individuals from three unrelated families displaying features of NF1 and NFNS. The genetic etiology of the clinical phenotypes was investigated by mutation analysis, including NF1, PTPN11, SOS1, KRAS, NRAS, BRAF, RAF1, SHOC2, SPRED1, MAP2K1, MAP2K2, and CBL. All three families harbored a heterozygous NF1 variant, where the first family had a missense variant, c.5425C>T;p.R1809C, the second family a recurrent 4bp-deletion, c.6789_6792delTTAC;p.Y2264Tfs*6, and the third family a splice-site variant, c.2991-1G>A, resulting in skipping of exon 18 and an in-frame deletion of 41 amino acids. These NF1 variants have all previously been reported in NF1 patients. Surprisingly, both c.6789_6792delTTAC and c.2991-1G>A are frequently associated with NF1, but association to NFNS has, to our knowledge, not previously been reported. Our results support the notion that NFNS represents a variant of NF1, genetically distinct from NS, and is caused by mutations in NF1, some of which also cause classical NF1. Due to phenotypic overlap between NFNS and NS, we propose screening for NF1 mutations in NS patients, preferentially when café-au-lait spots are present.
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Affiliation(s)
- Sara Ekvall
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
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Ekvall S, Hagenäs L, Allanson J, Annerén G, Bondeson ML. Co-occurring SHOC2 and PTPN11 mutations in a patient with severe/complex Noonan syndrome-like phenotype. Am J Med Genet A 2011; 155A:1217-24. [DOI: 10.1002/ajmg.a.33987] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2010] [Accepted: 02/07/2011] [Indexed: 12/17/2022]
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Allanson JE, Annerén G, Aoki Y, Armour CM, Bondeson ML, Cave H, Gripp KW, Kerr B, Nystrom AM, Sol-Church K, Verloes A, Zenker M. Cardio-facio-cutaneous syndrome: does genotype predict phenotype? Am J Med Genet C Semin Med Genet 2011; 157C:129-35. [PMID: 21495173 DOI: 10.1002/ajmg.c.30295] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Cardio-facio-cutaneous (CFC) syndrome is a sporadic multiple congenital anomalies/mental retardation condition principally caused by mutations in BRAF, MEK1, and MEK2. Mutations in KRAS and SHOC2 lead to a phenotype with overlapping features. In approximately 10–30% of individuals with a clinical diagnosis of CFC, a mutation in one of these causative genes is not found. Cardinal features of CFC include congenital heart defects, a characteristic facial appearance, and ectodermal abnormalities. Additional features include failure to thrive with severe feeding problems, moderate to severe intellectual disability and short stature with relative macrocephaly. First described in 1986, more than 100 affected individuals are reported. Following the discovery of the causative genes, more information has emerged on the breadth of clinical features. Little, however, has been published on genotype–phenotype correlations. This clinical study of 186 children and young adults with mutation-proven CFC syndrome is the largest reported to date. BRAF mutations are documented in 140 individuals (approximately 75%), while 46 (approximately 25%) have a mutation in MEK 1 or MEK 2. The age range is 6 months to 32 years, the oldest individual being a female from the original report [Reynolds et al. (1986); Am J Med Genet 25:413–427]. While some clinical data on 136 are in the literature, 50 are not previously published. We provide new details of the breadth of phenotype and discuss the frequency of particular features in each genotypic group. Pulmonary stenosis is the only anomaly that demonstrates a statistically significant genotype–phenotype correlation, being more common in individuals with a BRAF mutation.
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Wittström E, Ponjavic V, Bondeson ML, Andréasson S. Anterior Segment Abnormalities and Angle-Closure Glaucoma in a Family with a Mutation in theBEST1Gene and Best Vitelliform Macular Dystrophy. Ophthalmic Genet 2011; 32:217-27. [DOI: 10.3109/13816810.2011.567884] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Wittström E, Ekvall S, Schatz P, Bondeson ML, Ponjavic V, Andréasson S. Morphological and functional changes in multifocal vitelliform retinopathy and biallelic mutations in BEST1. Ophthalmic Genet 2010; 32:83-96. [PMID: 21192766 DOI: 10.3109/13816810.2010.535890] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE To describe morphological and functional changes in a single patient with multifocal Best vitelliform macular dystrophy (BVMD) and to perform a genotype/phenotype correlation. METHODS The proband with multifocal BVMD and three of her family members were examined with electrooculography (EOG), full-field electroretinography (full-field ERG), multifocal electroretinography (mfERG) and optical coherence tomography (OCT). Genomic DNA was screened for mutation in the BEST1 gene by DNA sequencing analysis. RESULTS The proband was observed regularly during a follow-up period of 4 years. Full-field ERG demonstrated reduced and delayed responses of both rods and cones. OCT demonstrated intra- and subretinal fluid which seemed to fluctuate with periods of stress, similar to that seen in chronic central serous chorioretinopathy. Two distinct heterozygous BEST1 mutations were identified in the proband, the recurrent p.R141H mutation and the p.P233A mutation. Heterozygous p.R141H mutations were also identified in two family members, while p.P233A was a de novo mutation. Abnormal EOG findings were observed in both the proband and in the carriers of p.R141H. Heterozygous carriers showed delayed implicit times in a- and b-waves of combined total rod and cone full-field ERG responses. CONCLUSIONS The p.R141H mutation is frequently seen together with multifocal vitelliform retinopathy and biallelic mutations in BEST1. Our results show that carriers of the p.R141H mutation are clinically unaffected but present with abnormal EOG and full-field ERG findings. A patient with biallelic mutations of the BEST1 gene, causing multifocal BVMD with progressive, widespread functional disturbance of the retina, confirmed by full-field and mfERG is described.
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21
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Winberg J, Gustavsson P, Lagerstedt-Robinson K, Blennow E, Lundin J, Iwarsson E, Nordenström A, Anderlid BM, Bondeson ML, Nordenskjöld A, Nordgren A. Chimerism resulting from parthenogenetic activation and dispermic fertilization. Am J Med Genet A 2010; 152A:2277-86. [DOI: 10.1002/ajmg.a.33594] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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22
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Nyström AM, Ekvall S, Allanson J, Edeby C, Elinder M, Holmström G, Bondeson ML, Annerén G. Noonan syndrome and neurofibromatosis type I in a family with a novel mutation inNF1. Clin Genet 2009; 76:524-34. [DOI: 10.1111/j.1399-0004.2009.01233.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Carlsson PI, Fransen E, Stenberg E, Bondeson ML. The influence of genetic factors, smoking and cardiovascular diseases on human noise susceptibility. ACTA ACUST UNITED AC 2009. [DOI: 10.1080/16513860701194683] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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24
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Nyström AM, Ekvall S, Strömberg B, Holmström G, Thuresson AC, Annerén G, Bondeson ML. A severe form of Noonan syndrome and autosomal dominant café-au-lait spots - evidence for different genetic origins. Acta Paediatr 2009; 98:693-8. [PMID: 19120036 DOI: 10.1111/j.1651-2227.2008.01170.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
AIM The clinical overlap among Noonan syndrome (NS), cardio-facio-cutaneous (CFC), LEOPARD and Costello syndromes as well as Neurofibromatosis type 1 is extensive, which complicates the process of diagnosis. Further genotype-phenotype correlations are required to facilitate future diagnosis of these patients. Therefore, investigations of the genetic cause of a severe phenotype in a patient with NS and the presence of multiple café-au-lait spots (CAL) spots in the patient and four members of the family were performed. METHODS Mutation analyses of candidate genes, PTPN11, NF1, SPRED1 and SPRED2, associated with these syndromes, were conducted using DNA sequencing. RESULTS A previously identified de novo mutation, PTPN11 F285L and an inherited NF1 R1809C substitution in the index patient were found. However, neither PTPN11 F285L, NF1 R1809C, SPRED1 nor SPRED2 segregated with CAL spots in the family. The results indicate that the familial CAL spots trait in this family is caused by a mutation in another gene, distinct from previous genes associated with CAL spots in these syndromes. CONCLUSION We suggest that the atypical severe symptoms in the index patient may be caused by an additive effect on the F285L mutation in PTPN11 by another mutation, for example the NF1 R1809C or alternatively, the not yet identified gene mutation associated with CAL spots in this family.
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Affiliation(s)
- Anna-Maja Nyström
- Department of Genetics and Pathology, Uppsala University, Uppsala, Sweden
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Konings A, Van Laer L, Wiktorek-Smagur A, Rajkowska E, Pawelczyk M, Carlsson PI, Bondeson ML, Dudarewicz A, Vandevelde A, Fransen E, Huyghe J, Borg E, Sliwinska-Kowalska M, Van Camp G. Candidate gene association study for noise-induced hearing loss in two independent noise-exposed populations. Ann Hum Genet 2009; 73:215-24. [PMID: 19183343 DOI: 10.1111/j.1469-1809.2008.00499.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Millions of people are daily exposed to high levels of noise. Consequently, noise-induced hearing loss (NIHL) is one of the most important occupational health hazards worldwide. In this study, we performed an association study for NIHL based on a candidate gene approach. 644 Single Nucleotide Polymorphisms (SNPs) in 53 candidate genes were analyzed in two independent NIHL sample sets, a Swedish set and part of a Polish set. Eight SNPs with promising results were selected and analysed in the remaining part of the Polish samples. One SNP in PCDH15 (rs7095441), resulted in significant associations in both sample sets while two SNPs in MYH14 (rs667907 and rs588035), resulted in significant associations in the Polish sample set and significant interactions with noise exposure level in the Swedish sample set. Calculation of odds ratios revealed a significant association of rs588035 with NIHL in the Swedish high noise exposure level group. Our studies suggest that PCDH15 and MYH14 may be NIHL susceptibility genes, but further replication in independent sample sets is mandatory.
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Affiliation(s)
- A Konings
- Department of Medical Genetics, University of Antwerp, Universiteitsplein 1, Antwerp, Belgium
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Abstract
Structural variation is an important cause of genetic variation. Whole genome analysis techniques can efficiently identify copy-number variable regions but there is a need for targeted methods, to verify and accurately size variable regions, and to diagnose large sample cohorts. We have developed a technique based on multiplex amplification of size-coded selectively circularized genomic fragments, which is robust, cheaper and more rapid than current multiplex targeted copy-number assays.
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Affiliation(s)
- Magnus Isaksson
- Department of Genetics and Pathology, Uppsala University, Rudbeck Laboratory, Se-751 85 Uppsala, Sweden.
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27
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Konings A, Van Laer L, Pawelczyk M, Carlsson PI, Bondeson ML, Rajkowska E, Dudarewicz A, Vandevelde A, Fransen E, Huyghe J, Borg E, Sliwinska-Kowalska M, Van Camp G. Association between variations in CAT and noise-induced hearing loss in two independent noise-exposed populations. Hum Mol Genet 2007; 16:1872-83. [PMID: 17567781 DOI: 10.1093/hmg/ddm135] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Noise-induced hearing loss (NIHL) is an important occupational hazard that results from an interaction between genetic and environmental factors. Although the environmental risk factors have been studied quite extensively, little is known about the genetic factors. On the basis of multiple studies, it was proposed that oxidative stress plays an important role in the development of NIHL. Here, we investigated whether variations (single nucleotide polymorphisms; SNPs) in the catalase gene (CAT), one of the genes involved in oxidative stress, influence noise susceptibility. Audiometric data from 1261 Swedish and 4500 Polish noise-exposed labourers were analysed. DNA samples were collected from the 10% most susceptible and the 10% most resistant individuals. Twelve SNPs were selected and genotyped. Subsequently, the interaction between noise exposure and genotypes and their effect on NIHL were analysed using logistic regression. Significant interactions were observed between noise exposure levels and genotypes of two SNPs for the Swedish population and of five SNPs for the Polish population. Two of these SNPs were significant in both populations. The interaction between predictor haplotypes and tagSNP haplotypes and noise exposure levels and their effect on NIHL were also analysed, resulting in several significant associations. In conclusion, this study identified significant associations between catalase SNPs and haplotypes and susceptibility to development of NIHL. These results indicate that catalase is a NIHL susceptibility gene, but that the effect of CAT polymorphisms can only be detected when noise exposure levels are taken into account.
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Affiliation(s)
- Annelies Konings
- Department of Medical Genetics, University of Antwerp, B-2610 Antwerp, Belgium
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28
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Van Laer L, Carlsson PI, Ottschytsch N, Bondeson ML, Konings A, Vandevelde A, Dieltjens N, Fransen E, Snyders D, Borg E, Raes A, Van Camp G. The contribution of genes involved in potassium-recycling in the inner ear to noise-induced hearing loss. Hum Mutat 2006; 27:786-95. [PMID: 16823764 DOI: 10.1002/humu.20360] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Noise-induced hearing loss (NIHL) is one of the most important occupational diseases and, after presbyacusis, the most frequent cause of hearing loss. NIHL is a complex disease caused by an interaction between environmental and genetic factors. The various environmental factors involved in NIHL have been relatively extensively studied. On the other hand, little research has been performed on the genetic factors responsible for NIHL. To test whether the variation in genes involved in coupling of cells and potassium recycling in the inner ear might partly explain the variability in susceptibility to noise, we performed a case-control association study using 35 SNPs selected in 10 candidate genes on a total of 218 samples selected from a population of 1,261 Swedish male noise-exposed workers. We have obtained significant differences between susceptible and resistant individuals for the allele, genotype, and haplotype frequencies for three SNPs of the KCNE1 gene, and for the allele frequencies for one SNP of KCNQ1 and one SNP of KCNQ4. Patch-clamp experiments in high K+-concentrations using a Chinese hamster ovary (CHO) cell model were performed to investigate the possibility that the KCNE1-p.85N variant (NT_011512.10:g.21483550G>A; NP_00210.2:p.Asp85Asn) was causative for high noise susceptibility. The normalized current density generated by KCNQ1/KCNE1-p.85N channels, thus containing the susceptibility variant, differed significantly from that from wild-type channels. Furthermore, the midpoint potential of KCNQ1/KCNE1-p.85N channels (i.e., the voltage at which 50% of the channels are open) differed from that of wild-type channels. Further genetic and physiological studies will be necessary to confirm these findings.
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Affiliation(s)
- Lut Van Laer
- Department of Medical Genetics, University of Antwerp, Antwerp, Belgium.
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29
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Wester U, Bondeson ML, Edeby C, Annerén G. Clinical and molecular characterization of individuals with 18p deletion: a genotype-phenotype correlation. Am J Med Genet A 2006; 140:1164-71. [PMID: 16691587 DOI: 10.1002/ajmg.a.31260] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The deletion 18p syndrome is one of the most common chromosome abnormalities. The medical problems are mental and postnatal growth retardation, and sometimes malformations of the heart and brain. The individuals have some typical features, which might be easy to overlook and which are: ptosis, strabismus, hypertelorism, broad flat nose, micrognathia, big and low set ears. The aims of present study were to clinically and molecularly characterize the syndrome further in seven subjects with de novo 18p deletions and to perform genotype-phenotype correlation. All seven subjects had terminal deletions and no interstitial deletion was observed with subtelomeric FISH analyses. To define the extent of the 18p deletions and the parental origin of the deletion microsatellite- and FISH analyses were performed on genomic DNA and on lymphoblastoid cell lines of the study participants. Totally 19 chromosomes, 18 specific polymorphic microsatellite markers, and 5 BAC clones were used. The results revealed that the deletions were located in the centromeric region at 18p11.1 in four of the seven subjects. In the remaining three the breakpoints were located distal to 18p11.1 (18p11.21-p11.22). Four of the individuals had a paternal and three a maternal origin of the deletion. Genotype-phenotype correlation of the seven subjects suggests a correlation between the extent of the deleted region and the mental development. All the four children with a deletion in the centromeric region at 18p11.1 had a mental retardation (MR). Two of the three children with a more distal breakpoint (distal 18p11.21) had a normal mental development and one had a border-line mental retardation. There might be a critical region for the mental retardation located between 18p11.1 and 18p11.21. The children with a breakpoint at 18p11.1 had all a broad face, which was observed in only one of those with a more distal breakpoint, otherwise no genotype-phenotype correlation of the features was observed.
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Affiliation(s)
- Ulrika Wester
- Unit of Paediatrics, Department of Women and Children's Health, Uppsala University, Sweden
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30
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Bondeson ML, Nyström AM, Gunnarsson U, Vahlquist A. Connexin 26 (GJB2) Mutations in Two Swedish Patients with Atypical Vohwinkel (Mutilating Keratoderma plus Deafness) and KID Syndrome Both Extensively Treated with Acitretin. Acta Derm Venereol 2006; 86:503-8. [PMID: 17106596 DOI: 10.2340/00015555-0164] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Neuroectodermal syndromes involving the skin and inner ear may be associated with mutations in connexin proteins, which form gap junctions important for intercellular communication. Vohwinkel syndrome (keratodermia mutilans with hearing loss) and keratitis-ichthyosis-deafness (KID) syndrome are rare ectodermal dysplasias associated with dominant mutations in the GJB2 gene encoding connexin 26. We report here two patients, one with KID and one with Vohwinkel syndrome. Both displayed unusual clinical features and responded well to long-term treatment with oral retinoid. Mutation analysis revealed a novel GJB2 mutation p.Gly59Ser in the patient with Vohwinkel syndrome, whereas a recurrent mutation p.Asp50Asn was found in the patient with KID syndrome. The clinical features, particularly a proneness to skin cancer in the patient with Vohwinkel syndrome, are discussed in relation to the identified genotypes.
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Carlsson PI, Van Laer L, Borg E, Bondeson ML, Thys M, Fransen E, Van Camp G. The influence of genetic variation in oxidative stress genes on human noise susceptibility. Hear Res 2005; 202:87-96. [PMID: 15811702 DOI: 10.1016/j.heares.2004.09.005] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2004] [Accepted: 09/09/2004] [Indexed: 02/07/2023]
Abstract
Noise induced hearing loss (NIHL) is a complex disease caused by an interaction between genetic and environmental factors. Damage in the cochlea as a result of noise exposure appears to be mediated by reactive oxygen species (ROS). To investigate whether genetic variation in the human protective antioxidant system is associated with high or low susceptibility to NIHL, genetic polymorphisms derived from genes involved in the oxidative stress response were analysed in the 10% most susceptible and 10% most resistant extremes of 1200 Swedish noise-exposed workers. The genetic polymorphisms included 2 deletion polymorphisms for the GSTM1 and GSTT1 gene, and 14 SNPs derived from the CAT, SOD, GPX, GSR and GSTP1 genes. No significant differences were found between susceptible and resistant groups, providing no support for a major role of genetic variation of antioxidant enzymes in the susceptibility to NIHL.
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Lower KM, Solders G, Bondeson ML, Nelson J, Brun A, Crawford J, Malm G, Börjeson M, Turner G, Partington M, Gécz J. 1024C>T (R342X) is a recurrent PHF6 mutation also found in the original Börjeson–Forssman–Lehmann syndrome family. Eur J Hum Genet 2004; 12:787-9. [PMID: 15241480 DOI: 10.1038/sj.ejhg.5201228] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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Malm G, Bondeson ML, von Döbeln U, Månsson JE. [Mucopolysaccharidoses. New therapeutic possibilities increase the need of early diagnosis]. Lakartidningen 2002; 99:1804-9. [PMID: 12043480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
The mucopolysaccharide (MPS) diseases are a group of inherited, progressive, lysosomal disorders due to deficiencies in various enzymes involved in the lysosomal degradation of cellular glycosaminoglycans (GAG). The six MPS-diseases share clinical features, but each has unique characteristics as well. There is a wide variation in clinical symptomatology even within the same enzyme deficiency. The MPS-diseases are very rare, with only 1-2 affected children born yearly in Sweden (100.000 births). Prenatal diagnosis is available for each condition. Bone-marrow transplantation has been utilized to replace the enzyme deficiency in Hurler's syndrome (MPS I) and Maroteaux-Lamy's syndrome (MPS VI) for the past two decades. When performed before 18-24 months of age in Hurler's syndrome, mental development can be preserved. In this overview we present Swedish incidence and prevalence figures for the different forms of mucopolysaccharidosis, typical symptoms at onset, complications, diagnostic methods and a summary of the present status of research, and finally options for future treatment.
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Karsten SL, Voskoboeva E, Carlberg BM, Kleijer WJ, Tsnnesen T, Pettersson U, Bondeson ML. Identification of 9 novel IDS gene mutations in 19 unrelated Hunter syndrome (mucopolysaccharidosis Type II) patients. Mutations in brief no. 202. Online. Hum Mutat 2000; 12:433. [PMID: 10671065 DOI: 10.1002/(sici)1098-1004(1998)12:6<433::aid-humu12>3.0.co;2-m] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Hunter syndrome is an X-linked lysosomal storage disorder caused by a deficiency of the lysosomal enzyme iduronate-2-sulfatase (IDS). The IDS deficiency can be caused by several different types of mutations in the IDS gene. We have performed a molecular and mutation analysis of a total 19 unrelated MPS II patients of different ethnic origin and identified 19 different IDS mutations, 9 of which were novel and unique. SSCP analysis followed by DNA sequencing revealed four novel missense mutations: S143F, associated with the 562C-->T polymorphism, C184W, D269V and Y348H. Two novel nonsense mutations were found: Y103X (433C-->A) and Y234X (826C-->G). In two patients two novel minor insertions (42linsA and 499insA) were identified. In one patient a complete IDS deletion was found, extending from locus DXS1185 to locus DXS466).
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Affiliation(s)
- S L Karsten
- Beijer Laboratory, Department of Genetics and Pathology, Unit of Medical Genetics, Uppsala University, Box 589, S-751 23 Uppsala, Sweden
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Lagerstedt K, Carlberg BM, Karimi-Nejad R, Kleijer WJ, Bondeson ML. Analysis of a 43.6 kb deletion in a patient with Hunter syndrome (MPSII): identification of a fusion transcript including sequences from the gene W and the IDS gene. Hum Mutat 2000; 15:324-31. [PMID: 10737977 DOI: 10.1002/(sici)1098-1004(200004)15:4<324::aid-humu4>3.0.co;2-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Mucopolysaccharidosis type II (Hunter syndrome) is an X-linked lysosomal storage disorder. A novel mutation is described in an MPS II patient in whom the disorder is caused by a 43.6 kb deletion. Southern blot analysis, PCR analysis and subsequent sequencing of the deletion junction revealed that the deletion spans exons 1-7 of the iduronate-2-sulfatase (IDS) gene, the IDS-2 locus and exons 3-5 of the recently identified gene W. Short direct repeats of 12 bp were identified at both deletion breakpoints, suggesting that the deletion is the result of an illegitimate recombination event. A sequence motif (TGAGGA) which is identical to a consensus sequence frequently associated with deletions in man was identified at both breakpoints. This further supports the notion that this motif is a hot spot for recombination. Gene expression studies by RT-PCR analysis of total RNA derived from fibroblasts of the patient revealed the presence of a novel fusion transcript. DNA sequence analysis of the cDNA demonstrated that it consists of exons derived from both the gene W and the IDS gene. A similar but longer fusion transcript containing exons 2-4 of the gene W and exons 4-9 of the IDS gene could also be detected in RNA of normal cell lines originating from different tissues. This result further demonstrates the complex gene expression profile of the IDS region, which may contribute to the observed genomic instability of this region.
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Affiliation(s)
- K Lagerstedt
- Section of Medical Genetics, Department of Genetics and Pathology, Uppsala University, Rudbeck Laboratory, Uppsala, Sweden
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36
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Abstract
We describe a novel type of complex genetic rearrangement in the iduronate-2-sulfatase (IDS) gene of a severely affected MPSII patient. Southern blot analysis indicated an intragenic deletion of exons 5 and 6. The deletion spans 5,581 bp. Sequencing of the deletion junctions revealed a complex rearrangement involving duplications and inversions. A remaining 20 bp fragment (c) from the intron 6 sequence and two duplicated IDS gene fragments of 314 bp (a) from intron 6/exon 7 boundary and 23 bp (b) from exon 7 were found between the deletion breakpoints. Fragments a and c were placed in an inverted orientation. We suggest that the described rearrangement is a result of a nonhomologous recombination event at sites with little homology. The proposed model explaining this recombinational event involves the formation of "tetra-loop" single-stranded DNA structure during replication. The complexity of the described rearrangement and the lack of large homologous sequences at the mutational breakpoints suggest that complex molecular intermediates are formed during illegitimate recombination.
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Affiliation(s)
- S Karsten
- Section of Medical Genetics, Department of Genetics and Pathology, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden
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37
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Karsten S, Voskoboeva E, Tishkanina S, Pettersson U, Krasnopolskaja X, Bondeson ML. Mutational spectrum of the iduronate-2-sulfatase (IDS) gene in 36 unrelated Russian MPS II patients. Hum Genet 1998; 103:732-5. [PMID: 9921913 DOI: 10.1007/s004390050901] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
We present a mutational analysis of the iduronate-2-sulfatase (IDS) gene of 36 Russian patients with Hunter syndrome. Among 29 mutant alleles, there were 19 missense mutations, 1 nonsense mutation, 6 mutations affecting splice sites, and 3 major structural alterations resulting in deletions. Of the 25 different mutations, 15 are novel and unique. Most of the missense mutations result in intermediate or severe phenotypes.
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Affiliation(s)
- S Karsten
- Department of Genetics and Pathology, Uppsala University, Sweden
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Bunge S, Rathmann M, Steglich C, Bondeson ML, Tylki-Szymanska A, Popowska E, Gal A. Homologous nonallelic recombinations between the iduronate-sulfatase gene and pseudogene cause various intragenic deletions and inversions in patients with mucopolysaccharidosis type II. Eur J Hum Genet 1998; 6:492-500. [PMID: 9801874 DOI: 10.1038/sj.ejhg.5200213] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
About 20% of patients with mucopolysaccharidosis type II (MPS II) have gross structural rearrangements involving the iduronate-sulfatase (IDS) gene in Xq27.3-q28. A nearby IDS pseudogene (IDS-2) promotes nonallelic recombination between highly homologous sequences. Here we describe major rearrangements due to gene/pseudogene recombination. In two unrelated patients, partial IDS gene deletions were found joining introns 3 and 7 of the IDS gene together with gene to pseudogene conversion in the area of breakpoints. In a third patient, a junction between intron 3 of IDS-2 and intron 7 of IDS was seen that was due to a deletion and inversion of the 5' part of the gene. Characterisation of breakpoints in six patients with large inversions revealed that all recombinations of this type occurred in the same area of homology between IDS and IDS-2; they were molecularly balanced, and accompanied by gene conversions in most cases. Apart from diagnostic implications, such naturally occurring recombination 'hot spots' may allow some insight into general features of crossover events in mammals.
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Affiliation(s)
- S Bunge
- Institut für Humangenetik, Universitäts-Krankenhaus Eppendorf, Hamburg, Germany.
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39
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Karsten SL, Lagerstedt K, Carlberg BM, Kleijer WJ, Zaremba J, Van Diggelen OP, Czartoryska B, Pettersson U, Bondeson ML. Two distinct deletions in the IDS gene and the gene W: a novel type of mutation associated with the Hunter syndrome. Genomics 1997; 43:123-9. [PMID: 9244428 DOI: 10.1006/geno.1997.4811] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A novel mutation has been identified in a patient with the Hunter syndrome (mucopolysaccharidosis type II), in whom the disorder is associated with two distinct deletions separated by 30 kb. The deletions were characterized by Southern blot and PCR analyses, and the nucleotide sequences at both junctions were determined. The first deletion, corresponding to a loss of 3152 bp of DNA, included exons 5 and 6 of the iduronate-2-sulfatase (IDS) gene. The second deletion was 3603 bp long and included exons 3 and 4 of gene W, which is located in the DXS466 locus telomeric of the IDS gene. Both deletions are the result of nonhomologous (illegitimate) recombination events between short direct repeats at the deletion breakpoints. An interesting finding was the presence of the heptamer sequence 5'-TACTCTA-3' present at both deletion junctions, suggesting that this motif might be a hot spot for recombination. We propose that the double deletion is the result of homology-associated nonhomologous recombinations caused by the presence of large duplicated regions in Xq27.3-q28.
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Affiliation(s)
- S L Karsten
- Department of Medical Genetics, Uppsala University, Sweden
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40
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Lagerstedt K, Karsten SL, Carlberg BM, Kleijer WJ, Tönnesen T, Pettersson U, Bondeson ML. Double-strand breaks may initiate the inversion mutation causing the Hunter syndrome. Hum Mol Genet 1997; 6:627-33. [PMID: 9097969 DOI: 10.1093/hmg/6.4.627] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
We have previously shown that patients with the Hunter syndrome frequently have suffered from a recombination event between the IDS gene and its putative pseudogene, IDS-2, resulting in an inversion of the intervening DNA. The inversion, which might be the consequence of an intrachromosomal mispairing, is caused by homologous recombination between sequences located in intron 7 of the IDS gene and sequences located distal of exon 3 in IDS-2. In order to gain insight into the mechanisms causing the inversion, we have isolated both inversion junctions in six unrelated patients. DNA sequence analysis of the junctions showed that all recombinations have taken place within a 1 kb region where the sequence identity is >98%. An interesting finding was the identification of regions with alternating IDS gene and IDS-2 sequences present at one inversion junction, suggesting that the recombination event has been initiated by a double-strand break in intron 7 of the IDS gene. The results from this study suggest that homologous recombination in man could be explained by mechanisms similar to those described for Saccharomyces cerevisiae. The results also have practical implications for diagnosis of patients with the Hunter syndrome.
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Affiliation(s)
- K Lagerstedt
- Department of Medical Genetics, Uppsala University, Sweden
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41
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Timms KM, Bondeson ML, Ansari-Lari MA, Lagerstedt K, Muzny DM, Dugan-Rocha SP, Nelson DL, Pettersson U, Gibbs RA. Molecular and phenotypic variation in patients with severe Hunter syndrome. Hum Mol Genet 1997; 6:479-86. [PMID: 9147653 DOI: 10.1093/hmg/6.3.479] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Severe Hunter syndrome is a fatal X-linked lysosomal storage disorder caused by iduronate-2-sulphatase (IDS) deficiency. Patients with complete deletion of the IDS locus often have atypical phenotypes including ptosis, obstructive sleep apnoea, and the occurrence of seizures. We have used genomic DNA sequencing to identify several new genes in the IDS region. DNA deletion patients with atypical symptoms have been analysed to determine whether these atypical symptoms could be due to involvement of these other loci. The occurrence of seizures in two individuals correlated with a deletion extending proximal of IDS, up to and including part of the FMR2 locus. Other (non-seizure) symptoms were associated with distal deletions. In addition, a group of patients with no variant symptoms, and a characteristic rearrangement involving a recombination between the IDS gene and an adjacent IDS pseudogene (IDS psi), showed normal expression of loci distal to IDS. Together, these results identify FMR2 as a candidate gene for seizures, when mutated along with IDS.
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Affiliation(s)
- K M Timms
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
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42
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Abstract
Iduronate-2-sulfatase (IDS) is involved in the degradation of heparan sulfate and dermatan sulfate in the lysosomes, and a deficiency in this enzyme results in Hunter syndrome. A 2.3-kb cDNA clone that contains the entire coding sequence of IDS has previously been reported. Here we describe the identification of a 1.4-kb transcript that may encode an IDS-like enzyme. The predicted protein is identical to the previously described enzyme, except for the absence of the 207-amino-acid COOH-terminal domain, which is replaced by 7 amino-acids. Our data suggest that there might exist an additional form of the IDS enzyme in humans. The results from this study may have implications for the pathogenesis of the Hunter syndrome.
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Affiliation(s)
- H Malmgren
- Beijer Laboratory, Department of Medical Genetics, University of Uppsala, Sweden
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43
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Bondeson ML, Dahl N, Malmgren H, Kleijer WJ, Tönnesen T, Carlberg BM, Pettersson U. Inversion of the IDS gene resulting from recombination with IDS-related sequences is a common cause of the Hunter syndrome. Hum Mol Genet 1995; 4:615-21. [PMID: 7633410 DOI: 10.1093/hmg/4.4.615] [Citation(s) in RCA: 135] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
We have recently described the identification of a second IDS locus (IDS-2) located within 90 kb telomeric of the IDS gene (Bondeson et al. submitted). Here, we show that this region is involved in a recombination event with the IDS gene in about 13% of patients with the Hunter syndrome. Analysis of the resulting rearrangement at the molecular level showed that these patients have suffered a recombination event that results in a disruption of the IDS gene in intron 7 with an inversion of the intervening DNA. Interestingly, all of the six cases with a similar type of rearrangement showed recombination between intron 7 of the IDS gene and sequences close to exon 3 at the IDS-2 locus implying that these regions are hot spots for recombination. Analysis by nucleotide sequencing showed that the inversion is caused by recombination between homologous sequences present in the IDS gene and the IDS-2 locus. No detectable deletions or insertions were observed as a result of the recombination event. The results in this study have practical implications for diagnosis of the Hunter syndrome.
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Affiliation(s)
- M L Bondeson
- Beijer Laboratory, Department of Medical Genetics, Uppsala University, Sweden
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Bondeson ML, Malmgren H, Dahl N, Carlberg BM, Pettersson U. Presence of an IDS-related locus (IDS2) in Xq28 complicates the mutational analysis of Hunter syndrome. Eur J Hum Genet 1995; 3:219-27. [PMID: 8528670 DOI: 10.1159/000472302] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
A deficiency of the enzyme iduronate-2-sulfatase (IDS) is the cause of Hunter syndrome (mucopolysaccharidosis type II). Here, we report a study of the human IDS locus at Xq28. An unexpected finding was an IDS-related region (IDS2) which is located on the telomeric side of the IDS gene within 80 kb. We have identified sequences in this locus that are homologous to exons 2 and 3 as well as sequences homologous to introns 2, 3 and 7 of the IDS gene. The exon 3 sequences in the IDS gene and in the IDS2 locus showed 100% identity. The overall identities of the other identified regions were 96%. A locus for DXS466 was also found to be located close to IDS2. The existence of the IDS2 locus complicates the diagnosis of mutations in genomic DNA from patients with Hunter syndrome. However, information about the IDS2 locus makes it possible to analyze the IDS gene and the IDS2 locus separately after PCR amplification.
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Affiliation(s)
- M L Bondeson
- Beijer Laboratory, Department of Medical Genetics, University of Uppsala, Sweden
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