1
|
Abstract
The XPG/ERCC5 endonuclease was originally identified as the causative gene for Xeroderma Pigmentosum complementation group G. Ever since its discovery, in depth biochemical, structural and cell biological studies have provided detailed mechanistic insight into its function in excising DNA damage in nucleotide excision repair, together with the ERCC1–XPF endonuclease. In recent years, it has become evident that XPG has additional important roles in genome maintenance that are independent of its function in NER, as XPG has been implicated in protecting replication forks by promoting homologous recombination as well as in resolving R-loops. Here, we provide an overview of the multitasking of XPG in genome maintenance, by describing in detail how its activity in NER is regulated and the evidence that points to important functions outside of NER. Furthermore, we present the various disease phenotypes associated with inherited XPG deficiency and discuss current ideas on how XPG deficiency leads to these different types of disease.
Collapse
|
2
|
Feltes BC. Revisiting the structural features of the xeroderma pigmentosum proteins: Focus on mutations and knowledge gaps. MUTATION RESEARCH. REVIEWS IN MUTATION RESEARCH 2022; 789:108416. [PMID: 35690419 DOI: 10.1016/j.mrrev.2022.108416] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 03/23/2022] [Accepted: 03/24/2022] [Indexed: 06/15/2023]
Abstract
The nucleotide excision repair pathway is a broadly studied DNA repair mechanism because impairments of its key players, the xeroderma pigmentosum proteins (XPA to XPG), are associated with multiple hereditary diseases. Due to the massive number of novel mutations reported for these proteins and new structural data published every year, proper categorization and discussion of relevant observations is needed to organize this extensive inflow of knowledge. This review aims to revisit the structural data of all XP proteins while updating it with the information developed in of the past six years. Discussions and interpretations of mutation outcomes, mechanisms of action, and knowledge gaps regarding their structures are provided, as well as new perspectives based on recent research.
Collapse
Affiliation(s)
- Bruno César Feltes
- Department of Theoretical Informatics, Institute of Informatics, Department of Theoretical Informatics, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil; Department of Genetics, Institute of Bioscience, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil; Department of Biophysics, Institute of Bioscience, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil.
| |
Collapse
|
3
|
Tsutakawa SE, Bacolla A, Katsonis P, Bralić A, Hamdan SM, Lichtarge O, Tainer JA, Tsai CL. Decoding Cancer Variants of Unknown Significance for Helicase-Nuclease-RPA Complexes Orchestrating DNA Repair During Transcription and Replication. Front Mol Biosci 2021; 8:791792. [PMID: 34966786 PMCID: PMC8710748 DOI: 10.3389/fmolb.2021.791792] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Accepted: 11/16/2021] [Indexed: 01/13/2023] Open
Abstract
All tumors have DNA mutations, and a predictive understanding of those mutations could inform clinical treatments. However, 40% of the mutations are variants of unknown significance (VUS), with the challenge being to objectively predict whether a VUS is pathogenic and supports the tumor or whether it is benign. To objectively decode VUS, we mapped cancer sequence data and evolutionary trace (ET) scores onto crystallography and cryo-electron microscopy structures with variant impacts quantitated by evolutionary action (EA) measures. As tumors depend on helicases and nucleases to deal with transcription/replication stress, we targeted helicase–nuclease–RPA complexes: (1) XPB-XPD (within TFIIH), XPF-ERCC1, XPG, and RPA for transcription and nucleotide excision repair pathways and (2) BLM, EXO5, and RPA plus DNA2 for stalled replication fork restart. As validation, EA scoring predicts severe effects for most disease mutations, but disease mutants with low ET scores not only are likely destabilizing but also disrupt sophisticated allosteric mechanisms. For sites of disease mutations and VUS predicted to be severe, we found strong co-localization to ordered regions. Rare discrepancies highlighted the different survival requirements between disease and tumor mutations, as well as the value of examining proteins within complexes. In a genome-wide analysis of 33 cancer types, we found correlation between the number of mutations in each tumor and which pathways or functional processes in which the mutations occur, revealing different mutagenic routes to tumorigenesis. We also found upregulation of ancient genes including BLM, which supports a non-random and concerted cancer process: reversion to a unicellular, proliferation-uncontrolled, status by breaking multicellular constraints on cell division. Together, these genes and global analyses challenge the binary “driver” and “passenger” mutation paradigm, support a gradient impact as revealed by EA scoring from moderate to severe at a single gene level, and indicate reduced regulation as well as activity. The objective quantitative assessment of VUS scoring and gene overexpression in the context of functional interactions and pathways provides insights for biology, oncology, and precision medicine.
Collapse
Affiliation(s)
- Susan E Tsutakawa
- Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Albino Bacolla
- Department of Molecular and Cellular Oncology, University of Texas M.D. Anderson Cancer Center, Houston, TX, United States
| | - Panagiotis Katsonis
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Amer Bralić
- Laboratory of DNA Replication and Recombination, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Samir M Hamdan
- Laboratory of DNA Replication and Recombination, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Olivier Lichtarge
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - John A Tainer
- Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA, United States.,Department of Molecular and Cellular Oncology, University of Texas M.D. Anderson Cancer Center, Houston, TX, United States.,Department of Cancer Biology, University of Texas M.D. Anderson Cancer Center, Houston, TX, United States
| | - Chi-Lin Tsai
- Department of Molecular and Cellular Oncology, University of Texas M.D. Anderson Cancer Center, Houston, TX, United States
| |
Collapse
|
4
|
Piccione M, Belloni Fortina A, Ferri G, Andolina G, Beretta L, Cividini A, De Marni E, Caroppo F, Citernesi U, Di Liddo R. Xeroderma Pigmentosum: General Aspects and Management. J Pers Med 2021; 11:1146. [PMID: 34834498 PMCID: PMC8624855 DOI: 10.3390/jpm11111146] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Revised: 10/27/2021] [Accepted: 10/28/2021] [Indexed: 01/25/2023] Open
Abstract
Xeroderma Pigmentosum (XP) is a rare genetic syndrome with a defective DNA nucleotide excision repair. It is characterized by (i) an extreme sensitivity to ultraviolet (UV)-induced damages in the skin and eyes; (ii) high risk to develop multiple skin tumours; and (iii) neurologic alterations in the most severe form. To date, the management of XP patients consists of (i) early diagnosis; (ii) a long-life protection from ultraviolet radiation, including avoidance of unnecessary UV exposure, wearing UV blocking clothing, and use of topical sunscreens; and (iii) surgical resections of skin cancers. No curative treatment is available at present. Thus, in the last decade, in order to prevent or delay the progression of the clinical signs of XP, numerous strategies have been proposed and tested, in some cases, with adverse effects. The present review provides an overview of the molecular mechanisms featuring the development of XP and highlights both advantages and disadvantages of the clinical approaches developed throughout the years. The intention of the authors is to sensitize scientists to the crucial aspects of the pathology that could be differently targeted. In this context, the exploration of the process underlining the conception of liposomal nanocarriers is reported to focus the attention on the potentialities of liposomal technology to optimize the administration of chemoprotective agents in XP patients.
Collapse
Affiliation(s)
- Monica Piccione
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, 35131 Padova, Italy
| | - Anna Belloni Fortina
- Pediatric Dermatology Unit, Department of Medicine DIMED, University of Padova, 35128 Padova, Italy; (A.B.F.); (F.C.)
| | - Giulia Ferri
- I.R.A. Istituto Ricerche Applicate S.p.A., 20865 Usmate Velate, Italy; (G.F.); (G.A.); (L.B.); (A.C.); (E.D.M.); (U.C.)
| | - Gloria Andolina
- I.R.A. Istituto Ricerche Applicate S.p.A., 20865 Usmate Velate, Italy; (G.F.); (G.A.); (L.B.); (A.C.); (E.D.M.); (U.C.)
| | - Lorenzo Beretta
- I.R.A. Istituto Ricerche Applicate S.p.A., 20865 Usmate Velate, Italy; (G.F.); (G.A.); (L.B.); (A.C.); (E.D.M.); (U.C.)
| | - Andrea Cividini
- I.R.A. Istituto Ricerche Applicate S.p.A., 20865 Usmate Velate, Italy; (G.F.); (G.A.); (L.B.); (A.C.); (E.D.M.); (U.C.)
| | - Emanuele De Marni
- I.R.A. Istituto Ricerche Applicate S.p.A., 20865 Usmate Velate, Italy; (G.F.); (G.A.); (L.B.); (A.C.); (E.D.M.); (U.C.)
| | - Francesca Caroppo
- Pediatric Dermatology Unit, Department of Medicine DIMED, University of Padova, 35128 Padova, Italy; (A.B.F.); (F.C.)
| | - Ugo Citernesi
- I.R.A. Istituto Ricerche Applicate S.p.A., 20865 Usmate Velate, Italy; (G.F.); (G.A.); (L.B.); (A.C.); (E.D.M.); (U.C.)
| | - Rosa Di Liddo
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, 35131 Padova, Italy
| |
Collapse
|
5
|
Kajitani GS, Nascimento LLDS, Neves MRDC, Leandro GDS, Garcia CCM, Menck CFM. Transcription blockage by DNA damage in nucleotide excision repair-related neurological dysfunctions. Semin Cell Dev Biol 2021; 114:20-35. [DOI: 10.1016/j.semcdb.2020.10.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 08/18/2020] [Accepted: 10/07/2020] [Indexed: 12/20/2022]
|
6
|
Pereira TDSF, Castro LP, Menck CFM, Maia MHT, Souza LLD, Fonseca FP, Pontes HAR, Pontes FSC, Gomez RS. Xeroderma pigmentosum variant: squamous cell carcinoma of the lower lip harboring exon 11 mutation of POLH. Oral Surg Oral Med Oral Pathol Oral Radiol 2021; 132:e97-e105. [PMID: 34030998 DOI: 10.1016/j.oooo.2021.03.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 02/09/2021] [Accepted: 03/21/2021] [Indexed: 10/21/2022]
Abstract
Xeroderma pigmentosum (XP) is a rare inherited disease caused by deficiencies in DNA damage repair, which mainly results from the failure of nucleotide excision repair or defects in translesion DNA synthesis. The development of multiple malignancies is one of the most prominent features of this condition, which is clinically characterized by the occurrence of hyperpigmentation and lesions associated with sunlight exposure. Lip squamous cell carcinoma in patients with XP has rarely been reported, and information regarding the genetic analysis of these patients is limited. In this report, a case of a 20-year-old patient who developed squamous cell carcinoma in the lower lip is described. Although the tumor was surgically excised, the patient presented with recurrence a few months later. Targeted sequencing using a customized panel of DNA repair genes revealed a mutation in POLH, the gene encoding DNA polymerase eta. Therefore, molecular characterization is important to further improve the understanding of possible phenotype-genotype correlations and mechanisms involved in the pathogenesis of XP.
Collapse
Affiliation(s)
| | - Ligia Pereira Castro
- Department of Microbiology, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | | | - Maria Helena Thomaz Maia
- Human and Medical Genetics, Institute of Biological Sciences, Federal University of Pará, Belém, Pará, Brazil
| | - Lucas Lacerda de Souza
- Department of Oral Pathology, University Hospital João de Barros Barreto, Federal University of Pará, Belém, Pará, Brazil
| | - Felipe Paiva Fonseca
- Department of Oral Surgery and Pathology, School of Dentistry, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Helder Antônio Rebelo Pontes
- Department of Oral Pathology, University Hospital João de Barros Barreto, Federal University of Pará, Belém, Pará, Brazil
| | - Flavia Sirotheau Correa Pontes
- Department of Oral Pathology, University Hospital João de Barros Barreto, Federal University of Pará, Belém, Pará, Brazil
| | - Ricardo Santiago Gomez
- Department of Oral Surgery and Pathology, School of Dentistry, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
| |
Collapse
|
7
|
Toprani SM, Kelkar Mane V. A short review on DNA damage and repair effects in lip cancer. Hematol Oncol Stem Cell Ther 2021; 14:267-274. [PMID: 33626329 DOI: 10.1016/j.hemonc.2021.01.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 01/20/2021] [Accepted: 01/26/2021] [Indexed: 11/28/2022] Open
Abstract
Increasing trend in oral cancer (0.6% per year) and its related mortality has been reported worldwide since 2010. The United States alone reports an increase of 57% within the past 10 years. This emphasizes the need not only for designing strategies of prevention and planning but also for an effective treatment regime for the various oral cancers. Cancers of the lips, tongue, cheeks, floor of the mouth, and hard palate have been primarily classified under the category of oral cancers. If left undiagnosed, these cancers can be life threatening. Amongst these, the most undesignated and understudied cancer type is the lip carcinoma, which is either categorized under oral cancer or/as well as skin cancer or head and neck cancer. However, lip cancer corresponds to 25-30% of all diagnosed oral cancers. Though the etiology of lip cancer is not yet fully understood, numerous risk factors involved in its development are now being studied. The cells in the lip region are continuously exposed to various DNA damaging agents from endogenous as well as exogenous sources. Flaws in DNA repair mechanisms involved in eliminating these damages may be linked to the origin of carcinogenesis. Accumulation of DNA damage and defect in repair mechanisms may play a role in lip carcinogenesis and progression. This literature review is an exhaustive compilation of the research work performed on the role of DNA damage and repair responses in lip carcinoma which will pave a path for researchers to identify predictive DNA repair biomarker/s for lip cancer, and its diagnosis, prevention, and treatment.
Collapse
Affiliation(s)
- Sneh M Toprani
- Department of Biotechnology, University of Mumbai, Mumbai, India; John B Little Center of Radiation Sciences, Department of Environmental Health, Harvard T H Chan School of Public Health, Boston, MA 02115, USA.
| | - Varsha Kelkar Mane
- John B Little Center of Radiation Sciences, Department of Environmental Health, Harvard T H Chan School of Public Health, Boston, MA 02115, USA
| |
Collapse
|
8
|
Panigrahi I, Shankar Prasad BA, Kaur H, Kalra J. COFS type 3 in an Indian family with antenatally detected arthrogryposis. Am J Med Genet A 2020; 185:631-635. [PMID: 33219753 DOI: 10.1002/ajmg.a.61979] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Revised: 10/28/2020] [Accepted: 10/31/2020] [Indexed: 11/09/2022]
Abstract
Fetal akinesia and contractures can be caused by mutations in various genes that lead to overlapping phenotypes with contractures, rocker bottom feet, cerebellar hypoplasia, ventriculomegaly, growth retardation, pulmonary hypoplasia, cystic hygroma and cleft palate in various combinations. Cerebro-oculo-facio-skeletal (COFS) syndrome is a condition resulting from defects in DNA repair pathway, and genes involved include ERCC1 (COFS), ERCC2 (XPD), ERCC5(XPG), and ERCC6 (CSB). It is a severe disorder presenting in fetal or neonatal period with microcephaly, arthrogryposis, prominent nose, and kyphoscoliosis, and leads to early death in childhood. We report a baby with antenatally identified arthrogryposis in which the homozygous pathogenic variant in exon 8 was identified in ERCC5 gene, by targeted next generation sequencing. This was predicted to cause premature chain termination in the protein. ERCC5 gene is mainly implicated in xeroderma pigmentosum, sometimes in COFS syndrome.
Collapse
Affiliation(s)
| | | | - Harleen Kaur
- Department of Pediatrics, PGIMER, Chandigarh, India
| | - Jasvinder Kalra
- Department of Obstetrics and Gynecology, PGIMER, Chandigarh, India
| |
Collapse
|
9
|
González-Corrochano R, Ruiz FM, Taylor NMI, Huecas S, Drakulic S, Spínola-Amilibia M, Fernández-Tornero C. The crystal structure of human XPG, the xeroderma pigmentosum group G endonuclease, provides insight into nucleotide excision DNA repair. Nucleic Acids Res 2020; 48:9943-9958. [PMID: 32821917 PMCID: PMC7515719 DOI: 10.1093/nar/gkaa688] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 08/04/2020] [Accepted: 08/06/2020] [Indexed: 01/14/2023] Open
Abstract
Nucleotide excision repair (NER) is an essential pathway to remove bulky lesions affecting one strand of DNA. Defects in components of this repair system are at the ground of genetic diseases such as xeroderma pigmentosum (XP) and Cockayne syndrome (CS). The XP complementation group G (XPG) endonuclease cleaves the damaged DNA strand on the 3′ side of the lesion coordinated with DNA re-synthesis. Here, we determined crystal structures of the XPG nuclease domain in the absence and presence of DNA. The overall fold exhibits similarities to other flap endonucleases but XPG harbors a dynamic helical arch that is uniquely oriented and defines a gateway. DNA binding through a helix-2-turn-helix motif, assisted by one flanking α-helix on each side, shows high plasticity, which is likely relevant for DNA scanning. A positively-charged canyon defined by the hydrophobic wedge and β-pin motifs provides an additional DNA-binding surface. Mutational analysis identifies helical arch residues that play critical roles in XPG function. A model for XPG participation in NER is proposed. Our structures and biochemical data represent a valuable tool to understand the atomic ground of XP and CS, and constitute a starting point for potential therapeutic applications.
Collapse
Affiliation(s)
| | - Federico M Ruiz
- Centro de Investigaciones Biológicas Margarita Salas, CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Nicholas M I Taylor
- Centro de Investigaciones Biológicas Margarita Salas, CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Sonia Huecas
- Centro de Investigaciones Biológicas Margarita Salas, CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Srdja Drakulic
- Centro de Investigaciones Biológicas Margarita Salas, CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain
| | | | - Carlos Fernández-Tornero
- Centro de Investigaciones Biológicas Margarita Salas, CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain
| |
Collapse
|
10
|
Human XPG nuclease structure, assembly, and activities with insights for neurodegeneration and cancer from pathogenic mutations. Proc Natl Acad Sci U S A 2020; 117:14127-14138. [PMID: 32522879 PMCID: PMC7321962 DOI: 10.1073/pnas.1921311117] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
DNA repair is essential to life and to avoidance of genome instability and cancer. Xeroderma pigmentosum group G (XPG) protein acts in multiple DNA repair pathways, both as an active enzyme and as a scaffold for coordinating with other repair proteins. We present here the structure of the catalytic domain responsible for its DNA binding and nuclease activity. Our analysis provides structure-based hypotheses for how XPG recognizes its bubble DNA substrate and predictions of the structural impacts of XPG disease mutations associated with two phenotypically distinct diseases: xeroderma pigmentosum (XP, skin cancer prone) or Cockayne syndrome (XP/CS, severe progressive developmental defects). Xeroderma pigmentosum group G (XPG) protein is both a functional partner in multiple DNA damage responses (DDR) and a pathway coordinator and structure-specific endonuclease in nucleotide excision repair (NER). Different mutations in the XPG gene ERCC5 lead to either of two distinct human diseases: Cancer-prone xeroderma pigmentosum (XP-G) or the fatal neurodevelopmental disorder Cockayne syndrome (XP-G/CS). To address the enigmatic structural mechanism for these differing disease phenotypes and for XPG’s role in multiple DDRs, here we determined the crystal structure of human XPG catalytic domain (XPGcat), revealing XPG-specific features for its activities and regulation. Furthermore, XPG DNA binding elements conserved with FEN1 superfamily members enable insights on DNA interactions. Notably, all but one of the known pathogenic point mutations map to XPGcat, and both XP-G and XP-G/CS mutations destabilize XPG and reduce its cellular protein levels. Mapping the distinct mutation classes provides structure-based predictions for disease phenotypes: Residues mutated in XP-G are positioned to reduce local stability and NER activity, whereas residues mutated in XP-G/CS have implied long-range structural defects that would likely disrupt stability of the whole protein, and thus interfere with its functional interactions. Combined data from crystallography, biochemistry, small angle X-ray scattering, and electron microscopy unveil an XPG homodimer that binds, unstacks, and sculpts duplex DNA at internal unpaired regions (bubbles) into strongly bent structures, and suggest how XPG complexes may bind both NER bubble junctions and replication forks. Collective results support XPG scaffolding and DNA sculpting functions in multiple DDR processes to maintain genome stability.
Collapse
|
11
|
Ferri D, Orioli D, Botta E. Heterogeneity and overlaps in nucleotide excision repair disorders. Clin Genet 2019; 97:12-24. [PMID: 30919937 DOI: 10.1111/cge.13545] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 02/27/2019] [Accepted: 03/26/2019] [Indexed: 12/22/2022]
Abstract
Nucleotide excision repair (NER) is an essential DNA repair pathway devoted to the removal of bulky lesions such as photoproducts induced by the ultraviolet (UV) component of solar radiation. Deficiencies in NER typically result in a group of heterogeneous distinct disorders ranging from the mild UV sensitive syndrome to the cancer-prone xeroderma pigmentosum and the neurodevelopmental/progeroid conditions trichothiodystrophy, Cockayne syndrome and cerebro-oculo-facio-skeletal-syndrome. A complicated genetic scenario underlines these disorders with the same gene linked to different clinical entities as well as different genes associated with the same disease. Overlap syndromes with combined hallmark features of different NER disorders can occur and sporadic presentations showing extra features of the hematological disorder Fanconi Anemia or neurological manifestations mimicking Hungtinton disease-like syndromes have been described. Here, we discuss the multiple functions of the five major pleiotropic NER genes (ERCC3/XPB, ERCC2/XPD, ERCC5/XPG, ERCC1 and ERCC4/XPF) and their relevance in phenotypic complexity. We provide an update of mutational spectra and examine genotype-phenotype relationships. Finally, the molecular defects that could explain the puzzling overlap syndromes are discussed.
Collapse
Affiliation(s)
- Debora Ferri
- Istituto di Genetica Molecolare (IGM), Consiglio Nazionale delle Ricerche, Pavia, Italy
| | - Donata Orioli
- Istituto di Genetica Molecolare (IGM), Consiglio Nazionale delle Ricerche, Pavia, Italy
| | - Elena Botta
- Istituto di Genetica Molecolare (IGM), Consiglio Nazionale delle Ricerche, Pavia, Italy
| |
Collapse
|
12
|
Chikhaoui A, Elouej S, Nabouli I, Jones M, Lagarde A, Ben Rekaya M, Messaoud O, Hamdi Y, Zghal M, Delague V, Levy N, De Sandre-Giovannoli A, Abdelhak S, Yacoub-Youssef H. Identification of a ERCC5 c.2333T>C (L778P) Variant in Two Tunisian Siblings With Mild Xeroderma Pigmentosum Phenotype. Front Genet 2019; 10:111. [PMID: 30838033 PMCID: PMC6383105 DOI: 10.3389/fgene.2019.00111] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 01/30/2019] [Indexed: 11/22/2022] Open
Abstract
Xeroderma pigmentosum (XP) is a rare autosomal recessive disorder due to a defect in the nucleotide excision repair (NER) DNA repair pathway, characterized by severe sunburn development of freckles, premature skin aging, and susceptibility to develop cancers at an average age of eight. XP is an example of accelerated photo-aging. It is a genetically and clinically heterogeneous disease. Eight complementation groups have been described worldwide. In Tunisia, five groups have been already identified. In this work, we investigated the genetic etiology in a family with an atypically mild XP phenotype. Two Tunisian siblings born from first-degree consanguineous parents underwent clinical examination in the dermatology department of the Charles Nicolle Hospital on the basis of acute sunburn reaction and mild neurological disorders. Blood samples were collected from two affected siblings after written informed consent. As all mutations reported in Tunisia have been excluded using Sanger sequencing, we carried out mutational analysis through a targeted panel of gene sequencing using the Agilent HaloPlex target enrichment system. Our clinical study shows, in both patients, the presence of achromic macula in sun exposed area with dermatological feature suggestive of Xeroderma pigmentosum disease. No developmental and neurological disorders were observed except mild intellectual disability. Genetic investigation shows that both patients were carriers of an homozygous T to C transition at the nucleotide position c.2333, causing the leucine to proline amino acid change at the position 778 (p.Leu778Pro) of the ERCC5 gene, and resulting in an XP-G phenotype. The same variation was previously reported at the heterozygous state in a patient cell line in Europe, for which no clinical data were available and was suggested to confer an XP/CS phenotype based on functional tests. This study contributes to further characterization of the mutation spectrum of XP in consanguineous Tunisian families and is potentially helpful for early diagnosis. It also indicates that the genotype-phenotype correlation is not always coherent for patients with mild clinical features. These data therefore suggest that targeted NGS is a highly informative diagnostic strategy, which can be used for XP molecular etiology determination.
Collapse
Affiliation(s)
- Asma Chikhaoui
- Laboratoire de Génomique Biomédicale et Oncogénétique, Institut Pasteur de Tunis, Université de Tunis El Manar, Tunis, Tunisia
| | - Sahar Elouej
- Laboratoire de Génomique Biomédicale et Oncogénétique, Institut Pasteur de Tunis, Université de Tunis El Manar, Tunis, Tunisia.,Aix Marseille Univ, Inserm, MMG, U 1251, Marseille, France
| | - Imen Nabouli
- Laboratoire de Génomique Biomédicale et Oncogénétique, Institut Pasteur de Tunis, Université de Tunis El Manar, Tunis, Tunisia
| | - Meriem Jones
- Laboratoire de Génomique Biomédicale et Oncogénétique, Institut Pasteur de Tunis, Université de Tunis El Manar, Tunis, Tunisia.,Service de Dermatologie, Hôpital Charles Nicolle, Tunis, Tunisia
| | - Arnaud Lagarde
- Aix Marseille Univ, Inserm, MMG, U 1251, Marseille, France
| | - Meriem Ben Rekaya
- Laboratoire de Génomique Biomédicale et Oncogénétique, Institut Pasteur de Tunis, Université de Tunis El Manar, Tunis, Tunisia
| | - Olfa Messaoud
- Laboratoire de Génomique Biomédicale et Oncogénétique, Institut Pasteur de Tunis, Université de Tunis El Manar, Tunis, Tunisia
| | - Yosr Hamdi
- Laboratoire de Génomique Biomédicale et Oncogénétique, Institut Pasteur de Tunis, Université de Tunis El Manar, Tunis, Tunisia
| | - Mohamed Zghal
- Service de Dermatologie, Hôpital Charles Nicolle, Tunis, Tunisia
| | | | - Nicolas Levy
- Aix Marseille Univ, Inserm, MMG, U 1251, Marseille, France.,Département de Génétique Médicale, AP-HM, Hôpital la Timone, Marseille, France
| | - Annachiara De Sandre-Giovannoli
- Aix Marseille Univ, Inserm, MMG, U 1251, Marseille, France.,Département de Génétique Médicale, AP-HM, Hôpital la Timone, Marseille, France
| | - Sonia Abdelhak
- Laboratoire de Génomique Biomédicale et Oncogénétique, Institut Pasteur de Tunis, Université de Tunis El Manar, Tunis, Tunisia
| | - Houda Yacoub-Youssef
- Laboratoire de Génomique Biomédicale et Oncogénétique, Institut Pasteur de Tunis, Université de Tunis El Manar, Tunis, Tunisia
| |
Collapse
|
13
|
Abstract
Xeroderma pigmentosum-Cockayne syndrome complex is a very rare multisystem degenerative disorder (Orpha: 220295; OMIM: 278730, 278760, 278780, 610651). Published information on XP-CS is mostly scattered throughout the literature. We compiled statistics related to symptom prevalence in XP-CS and have written a clinical description of the syndrome. We also drew on clinical practices used in XP and in Cockayne syndrome without XP to aid management of XP-CS. Extensive searches of the literature identified 43 XP-CS patients. The diagnosis had been confirmed with molecular or biochemical methods in 42 of them. Clinical features of each patient were summarized in spreadsheets and summary statistics were generated from this data. XP patients are classified into complementation groups according to the gene that is mutated. There are four groups in XP-CS, and classification was available for 42 patients. Twenty-one were in the XP-G complementation group, 13 in XP-D, 5 in XP-B, and 3 in XP-F. Overall, the clinical features of XP-CS are very similar to those of CS without XP, with the exception of skin cancers in XP-CS. However, one intriguing finding was that cancer incidence was lower in XP-CS compared to XP alone or XP-neurological disorder. The cancer rate in XP-CS was higher than in CS without XP, an unsurprising finding. There is preliminary evidence for the existence of severity groups in XP-CS, as is the case in CS. Although health problems in XP-CS vary both in severity and in when they the first occur, there was overall homogeneity between all complementation groups and putative severity groups. Severely affected patients met fewer milestones and died at younger ages compared to more mildly affected patients.
Collapse
|
14
|
Zhang J, Cheng R, Yu X, Sun Z, Li M, Yao Z. Expansion of the genotypic and phenotypic spectrum of xeroderma pigmentosum in Chinese population. PHOTODERMATOLOGY PHOTOIMMUNOLOGY & PHOTOMEDICINE 2017; 33:58-63. [PMID: 27982466 DOI: 10.1111/phpp.12283] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 12/02/2016] [Indexed: 11/26/2022]
Affiliation(s)
- Jia Zhang
- Department of Dermatology; Xinhua Hospital; Shanghai Jiaotong University School of Medicine; Shanghai China
| | - Ruhong Cheng
- Department of Dermatology; Xinhua Hospital; Shanghai Jiaotong University School of Medicine; Shanghai China
| | - Xia Yu
- Department of Dermatology; Xinhua Hospital; Shanghai Jiaotong University School of Medicine; Shanghai China
| | - Zhonghui Sun
- Department of Dermatology; Fengxian Institute of Dermatosis Prevention; Shanghai China
| | - Ming Li
- Department of Dermatology; Xinhua Hospital; Shanghai Jiaotong University School of Medicine; Shanghai China
| | - Zhirong Yao
- Department of Dermatology; Xinhua Hospital; Shanghai Jiaotong University School of Medicine; Shanghai China
| |
Collapse
|
15
|
Deep phenotyping of 89 xeroderma pigmentosum patients reveals unexpected heterogeneity dependent on the precise molecular defect. Proc Natl Acad Sci U S A 2016; 113:E1236-45. [PMID: 26884178 DOI: 10.1073/pnas.1519444113] [Citation(s) in RCA: 129] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Xeroderma pigmentosum (XP) is a rare DNA repair disorder characterized by increased susceptibility to UV radiation (UVR)-induced skin pigmentation, skin cancers, ocular surface disease, and, in some patients, sunburn and neurological degeneration. Genetically, it is assigned to eight complementation groups (XP-A to -G and variant). For the last 5 y, the UK national multidisciplinary XP service has provided follow-up for 89 XP patients, representing most of the XP patients in the United Kingdom. Causative mutations, DNA repair levels, and more than 60 clinical variables relating to dermatology, ophthalmology, and neurology have been measured, using scoring systems to categorize disease severity. This deep phenotyping has revealed unanticipated heterogeneity of clinical features, between and within complementation groups. Skin cancer is most common in XP-C, XP-E, and XP-V patients, previously considered to be the milder groups based on cellular analyses. These patients have normal sunburn reactions and are therefore diagnosed later and are less likely to adhere to UVR protection. XP-C patients are specifically hypersensitive to ocular damage, and XP-F and XP-G patients appear to be much less susceptible to skin cancer than other XP groups. Within XP groups, different mutations confer susceptibility or resistance to neurological damage. Our findings on this large cohort of XP patients under long-term follow-up reveal that XP is more heterogeneous than has previously been appreciated. Our data now enable provision of personalized prognostic information and management advice for each XP patient, as well as providing new insights into the functions of the XP proteins.
Collapse
|
16
|
Wang T, Xu CC, Zhou XP, Lee JJ, Shen J, Lian BQ, Liu YH, Lian CG. Novel germline ERCC5 mutations identified in a xeroderma pigmentosum complementation group G pedigree. JAAD Case Rep 2015; 1:66-70. [PMID: 27051686 PMCID: PMC4802556 DOI: 10.1016/j.jdcr.2014.12.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Affiliation(s)
- Tao Wang
- Department of Dermatology, Peking Union Medical College Hospital, Peking Union Medical College & Chinese Academy of Medical Sciences, Beijing, China
| | - Chen-chen Xu
- Department of Dermatology, Peking Union Medical College Hospital, Peking Union Medical College & Chinese Academy of Medical Sciences, Beijing, China
| | - Xi-ping Zhou
- Department of Dermatology, Peking Union Medical College Hospital, Peking Union Medical College & Chinese Academy of Medical Sciences, Beijing, China
| | - Jonathan J. Lee
- Program in Dermatopathology, Department of Pathology, Brigham & Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Jun Shen
- Partners Personalized Medicine, Department of Pathology, Brigham & Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Bill Q. Lian
- Department of Medicine, University of Massachusetts Memorial Medical Center, Worcester, Massachusetts
| | - Yue-Hua Liu
- Department of Dermatology, Peking Union Medical College Hospital, Peking Union Medical College & Chinese Academy of Medical Sciences, Beijing, China
- Correspondence to: Yue-Hua Liu, MD, Department of Dermatology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences Beijing, China.
| | - Christine Guo Lian
- Program in Dermatopathology, Department of Pathology, Brigham & Women's Hospital, Harvard Medical School, Boston, Massachusetts
- Christine Guo Lian, MD, Associate Dermatopathologist, Program in Dermatopathology, Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, 221 Longwood Ave, EBRC 401, Boston, MA 02115.
| |
Collapse
|
17
|
Sun Z, Zhang J, Guo Y, Ni C, Liang J, Cheng R, Li M, Yao Z. Genotype-phenotype correlation of xeroderma pigmentosum in a Chinese Han population. Br J Dermatol 2015; 172:1096-102. [PMID: 25256075 DOI: 10.1111/bjd.13429] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/17/2014] [Indexed: 12/14/2022]
Affiliation(s)
- Z. Sun
- Department of Dermatology; Fengxian Institute of Dermatosis Prevention; Shanghai China
- Department of Dermatology; Xinhua Hospital; Shanghai Jiaotong University School of Medicine; 1665 Kongjiang Road Shanghai 200092 China
| | - J. Zhang
- Department of Dermatology; Xinhua Hospital; Shanghai Jiaotong University School of Medicine; 1665 Kongjiang Road Shanghai 200092 China
| | - Y. Guo
- Department of Dermatology; Fengxian Institute of Dermatosis Prevention; Shanghai China
| | - C. Ni
- Department of Dermatology; Xinhua Hospital; Shanghai Jiaotong University School of Medicine; 1665 Kongjiang Road Shanghai 200092 China
| | - J. Liang
- Department of Dermatology; Xinhua Hospital; Shanghai Jiaotong University School of Medicine; 1665 Kongjiang Road Shanghai 200092 China
| | - R. Cheng
- Department of Dermatology; Xinhua Hospital; Shanghai Jiaotong University School of Medicine; 1665 Kongjiang Road Shanghai 200092 China
| | - M. Li
- Department of Dermatology; Xinhua Hospital; Shanghai Jiaotong University School of Medicine; 1665 Kongjiang Road Shanghai 200092 China
| | - Z. Yao
- Department of Dermatology; Xinhua Hospital; Shanghai Jiaotong University School of Medicine; 1665 Kongjiang Road Shanghai 200092 China
| |
Collapse
|
18
|
Feltes BC, Bonatto D. Overview of xeroderma pigmentosum proteins architecture, mutations and post-translational modifications. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2014; 763:306-20. [PMID: 25795128 DOI: 10.1016/j.mrrev.2014.12.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Revised: 12/08/2014] [Accepted: 12/09/2014] [Indexed: 12/15/2022]
Abstract
The xeroderma pigmentosum complementation group proteins (XPs), which include XPA through XPG, play a critical role in coordinating and promoting global genome and transcription-coupled nucleotide excision repair (GG-NER and TC-NER, respectively) pathways in eukaryotic cells. GG-NER and TC-NER are both required for the repair of bulky DNA lesions, such as those induced by UV radiation. Mutations in genes that encode XPs lead to the clinical condition xeroderma pigmentosum (XP). Although the roles of XPs in the GG-NER/TC-NER subpathways have been extensively studied, complete knowledge of their three-dimensional structure is only beginning to emerge. Hence, this review aims to summarize the current knowledge of mapped mutations and other structural information on XP proteins that influence their function and protein-protein interactions. We also review the possible post-translational modifications for each protein and the impact of these modifications on XP protein functions.
Collapse
Affiliation(s)
- Bruno César Feltes
- Biotechnology Center of the Federal University of Rio Grande do Sul, Department of Molecular Biology and Biotechnology, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Diego Bonatto
- Biotechnology Center of the Federal University of Rio Grande do Sul, Department of Molecular Biology and Biotechnology, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil.
| |
Collapse
|
19
|
Miętus M, Nowak E, Jaciuk M, Kustosz P, Studnicka J, Nowotny M. Crystal structure of the catalytic core of Rad2: insights into the mechanism of substrate binding. Nucleic Acids Res 2014; 42:10762-75. [PMID: 25120270 PMCID: PMC4176360 DOI: 10.1093/nar/gku729] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Revised: 07/29/2014] [Accepted: 07/29/2014] [Indexed: 12/26/2022] Open
Abstract
Rad2/XPG belongs to the flap nuclease family and is responsible for a key step of the eukaryotic nucleotide excision DNA repair (NER) pathway. To elucidate the mechanism of DNA binding by Rad2/XPG, we solved crystal structures of the catalytic core of Rad2 in complex with a substrate. Rad2 utilizes three structural modules for recognition of the double-stranded portion of DNA substrate, particularly a Rad2-specific α-helix for binding the cleaved strand. The protein does not specifically recognize the single-stranded portion of the nucleic acid. Our data suggest that in contrast to related enzymes (FEN1 and EXO1), the Rad2 active site may be more accessible, which would create an exit route for substrates without a free 5' end.
Collapse
Affiliation(s)
- Michał Miętus
- Laboratory of Protein Structure, International Institute of Molecular and Cell Biology, Warsaw 02-109, Poland
| | - Elżbieta Nowak
- Laboratory of Protein Structure, International Institute of Molecular and Cell Biology, Warsaw 02-109, Poland
| | - Marcin Jaciuk
- Laboratory of Protein Structure, International Institute of Molecular and Cell Biology, Warsaw 02-109, Poland
| | - Paweł Kustosz
- Laboratory of Protein Structure, International Institute of Molecular and Cell Biology, Warsaw 02-109, Poland
| | - Justyna Studnicka
- Laboratory of Protein Structure, International Institute of Molecular and Cell Biology, Warsaw 02-109, Poland
| | - Marcin Nowotny
- Laboratory of Protein Structure, International Institute of Molecular and Cell Biology, Warsaw 02-109, Poland
| |
Collapse
|
20
|
Moriwaki S, Saruwatari H, Kanzaki T, Kanekura T, Minoshima S. Trichothiodystrophy group A: A first Japanese patient with a novel homozygous nonsense mutation in theGTF2H5gene. J Dermatol 2014; 41:705-8. [DOI: 10.1111/1346-8138.12549] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 05/18/2014] [Indexed: 11/28/2022]
Affiliation(s)
- Shinichi Moriwaki
- Department of Dermatology; Osaka Medical College; Osaka
- Department of Photomedical Genomics; Basic Medical Photonics Laboratory; Medical Photonics Research Center; Hamamatsu University School of Medicine; Hamamatsu
| | - Hiroshi Saruwatari
- Department of Dermatology; Kagoshima University Graduate School of Medical and Dental Sciences; Kagoshima Japan
| | - Tamotsu Kanzaki
- Department of Dermatology; Kagoshima University Graduate School of Medical and Dental Sciences; Kagoshima Japan
| | - Takuro Kanekura
- Department of Dermatology; Kagoshima University Graduate School of Medical and Dental Sciences; Kagoshima Japan
| | - Shinsei Minoshima
- Department of Photomedical Genomics; Basic Medical Photonics Laboratory; Medical Photonics Research Center; Hamamatsu University School of Medicine; Hamamatsu
| |
Collapse
|
21
|
Salihu S, Güven O, Gllareva E, Prekazi M, Salihu L. A clinical study on survival rate of patients with squamous cell carcinoma of the lower lip in Kosovo. J Craniomaxillofac Surg 2014; 42:1773-7. [PMID: 25183172 DOI: 10.1016/j.jcms.2014.06.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2014] [Revised: 04/16/2014] [Accepted: 06/05/2014] [Indexed: 11/30/2022] Open
Abstract
OBJECTIVE The aim of this study is to find out the survival rate of patients with squamous cell carcinoma of the lower lip in Kosovo and to see the effect of stage of disease on the success of surgical treatment. PATIENTS AND METHODS 789 patients with SCCLL who were referred to the Department of Maxillofacial Surgery, University Clinical Centre of Kosovo, were examined during a period of 20 years (between 1993 and 2013). 614 (77.82%) of these patients received treatment and have regularly visited the department once every 3 months for post-operative controls. Data have been collected from these 614 patients for 10 years; thus the follow-up period lasts for 10 years for every patient under control. The collected data were analysed using Chi square test. Patients were classified by sex, aetiology, stage of the disease, location of the disease, the treatment patients received, metastasis rate and survival rate. RESULTS The most susceptible patients were those at ages between 50 and 70. The youngest patient was 8 years old whereas the oldest was 92. The male-female ratio was 5:1. 57% of the patients had been working outdoors and had been exposed to sunlight. Ten years survival rate for the Stages I, II, III and IV was 91.7%, 83.7%, 28% and 11.4% respectively. CONCLUSION It was found that the success of the surgery was closely related with the stage of disease and early diagnosis. Training the relevant parties (i.e., the people, family doctors etc.) on early diagnosis would improve the survival rate.
Collapse
Affiliation(s)
- Sami Salihu
- Department of Maxillofacial Surgery, University of Prishtina, Prishtina, Kosovo
| | - Orhan Güven
- Department of Maxillofacial Surgery, University of Ankara, School of Dentistry, Besevler, Ankara, Turkey.
| | - Enis Gllareva
- Department of Maxillofacial Surgery, University of Prishtina, Prishtina, Kosovo
| | - Mergime Prekazi
- Department of Maxillofacial Surgery, University of Prishtina, Prishtina, Kosovo
| | - Leminot Salihu
- Department of Maxillofacial Surgery, University of Prishtina, Prishtina, Kosovo
| |
Collapse
|
22
|
Drury S, Boustred C, Tekman M, Stanescu H, Kleta R, Lench N, Chitty LS, Scott RH. A novel homozygous ERCC5 truncating mutation in a family with prenatal arthrogryposis--further evidence of genotype-phenotype correlation. Am J Med Genet A 2014; 164A:1777-83. [PMID: 24700531 DOI: 10.1002/ajmg.a.36506] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Accepted: 01/30/2014] [Indexed: 11/10/2022]
Abstract
We report on a family with five fetuses conceived to first cousin parents presenting with abnormal ultrasound findings including contractures and microcephaly. Cerebellar hypoplasia and ventriculomegaly were also present in two and fetal edema developed in the one fetus that survived beyond 24 weeks of gestation. Linkage studies of 15 members of the family, including four affecteds, were undertaken followed by exome sequencing of one affected individual and their parents. Analysis of exome data was restricted to the 9.3 Mb largest shared region of homozygosity identified by linkage; a single novel homozygous mutation in the proband that was heterozygous in the parents (ERCC5 c.2766dupA, p.Leu923ThrfsX7) was identified. This segregated with disease. ERCC5 is a component of the nucleotide excision repair machinery and biallelic mutations in the gene have previously been associated with xeroderma pigmentosum (group G), Cockayne syndrome and the more severe cerebrooculofacioskeletal syndrome. The phenotype in the family we report on is consistent with a severe manifestation of cerebrooculofacioskeletal syndrome. Our data broaden the reported clinical spectrum of ERCC5 mutations and provide further evidence of genotype-phenotype correlation with truncating mutations being associated with severe phenotypes. They also demonstrate the molecular diagnostic power of a combined approach of linkage studies and exome sequencing in families with rare, genetically heterogeneous disorders and a well described pedigree.
Collapse
Affiliation(s)
- Suzanne Drury
- NE Thames Regional Genetics Service, Great Ormond Street Hospital for Children, London, United Kingdom
| | | | | | | | | | | | | | | |
Collapse
|
23
|
Schäfer A, Gratchev A, Seebode C, Hofmann L, Schubert S, Laspe P, Apel A, Ohlenbusch A, Tzvetkov M, Weishaupt C, Oji V, Schön MP, Emmert S. Functional and molecular genetic analyses of nine newly identified XPD-deficient patients reveal a novel mutation resulting in TTD as well as in XP/CS complex phenotypes. Exp Dermatol 2014; 22:486-9. [PMID: 23800062 DOI: 10.1111/exd.12166] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/03/2013] [Indexed: 11/29/2022]
Abstract
The xeroderma pigmentosum (XP) group D protein is involved in nucleotide excision repair (NER) as well as in basal transcription. Determined by the type of XPD mutation, six different clinical entities have been distinguished: XP, XP with neurological symptoms, trichothiodystrophy (TTD), XP⁄TTD complex, XP⁄Cockayne syndrome (CS) complex or the cerebro-oculo-facio-skeletal syndrome (COFS). We identified nine new XPD-deficient patients. Their fibroblasts showed reduced post-UV cell survival, reduced NER capacity, normal XPD mRNA expression and partly reduced XPD protein expression. Six patients exhibited a XP phenotype in accordance with established XP-causing mutations (c.2079G>A, p.R683Q; c.2078G>T, p.R683W; c.1833G>T, p.R601L; c.1878G>C, p.R616P; c.1878G>A, p.R616Q). One TTD patient was homozygous for the known TTD-causing mutation p.R722W (c.2195C>T). Two patients were compound heterozygous for a TTD-causing mutation (c.366G>A, p.R112H) and a novel p.D681H (c.2072G>C) amino acid exchange, but exhibited different TTD and XP/CS complex phenotypes, respectively. Interestingly, the XP/CS patient's cells exhibited a reduced but well detectable XPD protein expression compared with hardly detectable XPD expression of the TTD patient's cells. Same mutations with different clinical outcomes in NER-defective patients demonstrate the complexity of phenotype-genotype correlations, for example relating to additional genetic variations (parental consanguinity), different allelic expression due to SNPs or differences in the methylation status.
Collapse
|
24
|
Hijazi H, Salih M, Hamad M, Hassan H, Salih S, Mohamed K, Mukhtar M, Karrar Z, Ansari S, Ibrahim N, Alkuraya F. Pellagra-like condition is xeroderma pigmentosum/Cockayne syndrome complex and niacin confers clinical benefit. Clin Genet 2013; 87:56-61. [DOI: 10.1111/cge.12325] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Revised: 11/19/2013] [Accepted: 11/19/2013] [Indexed: 11/28/2022]
Affiliation(s)
- H. Hijazi
- Department of Genetics; King Faisal Specialist Hospital and Research Center; Riyadh Saudi Arabia
| | | | | | - H.H. Hassan
- Department of Radiology; King Khalid University Hospital and College of Medicine, King Saud University; Riyadh Saudi Arabia
| | - S.B.M. Salih
- Department of Pediatrics, Mafraq Hospital; Abu Dhabi United Arab Emirates
| | - K.A. Mohamed
- Department of Pediatrics (Neurology), Sheikh Khalifa Medical City; Abu Dhabi United Arab Emirates
| | - M.M. Mukhtar
- Institute of Endemic Diseases, Faculty of Medicine
| | - Z.A. Karrar
- Department of Pediatrics and Child Health, Faculty of Medicine; University of Khartoum; Khartoum Sudan
| | - S. Ansari
- Department of Genetics; King Faisal Specialist Hospital and Research Center; Riyadh Saudi Arabia
| | - N. Ibrahim
- Department of Genetics; King Faisal Specialist Hospital and Research Center; Riyadh Saudi Arabia
| | - F.S. Alkuraya
- Department of Genetics; King Faisal Specialist Hospital and Research Center; Riyadh Saudi Arabia
- Department of Anatomy and Cell Biology, College of Medicine; Alfaisal University; Riyadh Saudi Arabia
| |
Collapse
|
25
|
Jaarsma D, van der Pluijm I, van der Horst GT, Hoeijmakers JH. Cockayne syndrome pathogenesis: Lessons from mouse models. Mech Ageing Dev 2013; 134:180-95. [DOI: 10.1016/j.mad.2013.04.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Revised: 03/04/2013] [Accepted: 04/08/2013] [Indexed: 10/27/2022]
|
26
|
Soltys DT, Rocha CRR, Lerner LK, de Souza TA, Munford V, Cabral F, Nardo T, Stefanini M, Sarasin A, Cabral‐Neto JB, Menck CFM. Novel
XPG
(
ERCC5
) Mutations Affect
DNA
Repair and Cell Survival after Ultraviolet but not Oxidative Stress. Hum Mutat 2013; 34:481-9. [DOI: 10.1002/humu.22259] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2012] [Accepted: 11/30/2012] [Indexed: 11/05/2022]
Affiliation(s)
- Daniela T. Soltys
- Department of Microbiology, Institute of Biomedical Sciences University of São Paulo São Paulo SP Brazil
| | - Clarissa R. R. Rocha
- Department of Microbiology, Institute of Biomedical Sciences University of São Paulo São Paulo SP Brazil
| | - Letícia K. Lerner
- Department of Microbiology, Institute of Biomedical Sciences University of São Paulo São Paulo SP Brazil
| | - Tiago A. de Souza
- Department of Microbiology, Institute of Biomedical Sciences University of São Paulo São Paulo SP Brazil
| | - Veridiana Munford
- Department of Microbiology, Institute of Biomedical Sciences University of São Paulo São Paulo SP Brazil
| | - Fernanda Cabral
- Instituto de Biofísica Carlos Chagas Filho Federal University of Rio de Janeiro Rio de Janeiro RJ Brazil
| | - Tiziana Nardo
- Istituto di Genetica Molecolare Consiglio Nazionale delle Ricerche Pavia Italy
| | - Miria Stefanini
- Istituto di Genetica Molecolare Consiglio Nazionale delle Ricerche Pavia Italy
| | - Alain Sarasin
- Centre National de la Recherche Scientifique UMR8200 Institut Gustave Roussy, University Paris‐Sud Villejuif France
| | - Januário B. Cabral‐Neto
- Instituto de Biofísica Carlos Chagas Filho Federal University of Rio de Janeiro Rio de Janeiro RJ Brazil
| | - Carlos F. M. Menck
- Department of Microbiology, Institute of Biomedical Sciences University of São Paulo São Paulo SP Brazil
| |
Collapse
|
27
|
Characterization of three XPG-defective patients identifies three missense mutations that impair repair and transcription. J Invest Dermatol 2013; 133:1841-9. [PMID: 23370536 DOI: 10.1038/jid.2013.54] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Only 16 XPG-defective patients with 20 different mutations have been described. The current hypothesis is that missense mutations impair repair (xeroderma pigmentosum (XP) symptoms), whereas truncating mutations impair both repair and transcription (XP and Cockayne syndrome (CS) symptoms). We identified three cell lines of XPG-defective patients (XP40GO, XP72MA, and XP165MA). Patients' fibroblasts showed a reduced post-UVC cell survival. The reduced repair capability, assessed by host cell reactivation, could be complemented by XPG cDNA. XPG mRNA expression of XP165MA, XP72MA, and XP40GO was 83%, 97%, and 82.5%, respectively, compared with normal fibroblasts. XP165MA was homozygous for a p.G805R mutation; XP72MA and XP40GO were both compound heterozygous (p.W814S and p.E727X, and p.L778P and p.Q150X, respectively). Allele-specific complementation analysis of these five mutations revealed that p.L778P and p.W814S retained considerable residual repair activity. In line with the severe XP/CS phenotypes of XP72MA and XP165MA, even the missense mutations failed to interact with the transcription factor IIH subunits XPD and to some extent cdk7 in coimmunoprecipitation assays. Immunofluorescence techniques revealed that the mutations destabilized early recruitment of XP proteins to localized photodamage and delayed their redistribution in vivo. Thus, we identified three XPG missense mutations in the I-region of XPG that impaired repair and transcription and resulted in severe XP/CS.
Collapse
|