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Ahmed F, Blegen K, Tarbox M. An Atypical Presentation of Dyskeratosis Congenita in a Child With a Familial RTEL1 Mutation. Pediatr Dermatol 2024. [PMID: 39295224 DOI: 10.1111/pde.15750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2024] [Revised: 08/10/2024] [Accepted: 08/18/2024] [Indexed: 09/21/2024]
Abstract
Dyskeratosis congenita (DC) is a rare inherited bone marrow disease that classically presents with the triad of oral leukoplakia, nail dystrophy, and reticular hyperpigmentation. It is most commonly caused by a defect in the DKC1 gene involved in telomere stability. Malignant progression of oral leukoplakia to squamous cell carcinoma (SCC) is rare in DC, especially in younger patients, and cutaneous SCC is only reported in 1.5% of cases of DC. Here we report a case of a 12-year-old female with a familial heterozygous RTEL1 (regulator of telomere elongation helicase 1) gene mutation associated with a severe phenotype of DC characterized by multiple cutaneous SCCs.
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Affiliation(s)
- Faiza Ahmed
- Department of Dermatology, Texas Tech University Health Sciences Center, Lubbock, Texas, USA
| | - Kristina Blegen
- Department of Dermatology, Texas Tech University Health Sciences Center, Lubbock, Texas, USA
| | - Michelle Tarbox
- Department of Dermatology, Texas Tech University Health Sciences Center, Lubbock, Texas, USA
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2
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Guo Q, Zhang P, Ying W, Wang Y, Zhu J, Li G, Wang H, Wang X, Lei C, Zhou W, Sun J, Wu B. Intron retention by a novel intronic mutation in DKC1 gene caused recurrent still birth and early death in a Chinese family. Mol Genet Genomic Med 2022; 10:e1934. [PMID: 35384376 PMCID: PMC9184655 DOI: 10.1002/mgg3.1934] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Revised: 02/09/2022] [Accepted: 03/14/2022] [Indexed: 11/06/2022] Open
Abstract
Background DKC1, the dyskerin encoding gene, functions in telomerase activity and telomere maintenance. DKC1 mutations cause a multisystem disease, dyskeratosis congenita (DC), which is associated with immunodeficiency and bone marrow failure. Methods In this research, we reported a novel intronic mutation of DKC1 causing dyskerin functional loss in a Chinese family. Whole exome sequence (WES) of the proband and validation by sanger sequencing help us identify a pathogenic DKC1 mutation. Minigene splicing assays were performed to evaluate functional change of DKC1. Results A pathogenic DKC1 intronic mutation(c.84 + 7A > G) was identified in the proband, which was inherited from heterozygous mother and not reported before. We detected the novel transcript with a 7 bp intron retention through minigene splicing assay. The newly spliced transcript is so short that would be degraded by nonsense‐mediated mRNA decay in vitro and we infer that the novel DKC1 mutation would influences normal physiological function of dyskerin. Conclusions Our study identified a novel intronic mutation, which expands the spectrum of pathogenic DKC1 gene mutations and can be used in molecular diagnosis. The mutant allele was transmitted to the next generation with high frequency in the family and causes still birth or early death.
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Affiliation(s)
- Qiufang Guo
- Center of Molecular Medicine, Pediatrics Research Institute, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai, China.,Berry Genomics Co., Beijing, China
| | - Ping Zhang
- Center of Molecular Medicine, Pediatrics Research Institute, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai, China
| | - Wenjing Ying
- Department of Allergy and Clinical Immunology, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai, China
| | - Yaqiong Wang
- Center of Molecular Medicine, Pediatrics Research Institute, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai, China
| | - Jitao Zhu
- Center of Molecular Medicine, Pediatrics Research Institute, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai, China
| | - Gang Li
- Center of Molecular Medicine, Pediatrics Research Institute, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai, China
| | - Huijun Wang
- Center of Molecular Medicine, Pediatrics Research Institute, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai, China
| | - Xiaochuan Wang
- Center of Molecular Medicine, Pediatrics Research Institute, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai, China
| | - Caixia Lei
- Prenatal Diagnosis Center, Obstetrics and Gynecology Hospital of Fudan University, Shanghai, China
| | - Wenhao Zhou
- Center of Molecular Medicine, Pediatrics Research Institute, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai, China
| | - Jinqiao Sun
- Department of Allergy and Clinical Immunology, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai, China
| | - Bingbing Wu
- Center of Molecular Medicine, Pediatrics Research Institute, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai, China
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3
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Galati A, Scatolini L, Micheli E, Bavasso F, Cicconi A, Maccallini P, Chen L, Roake CM, Schoeftner S, Artandi SE, Gatti M, Cacchione S, Raffa GD. The S-adenosylmethionine analog sinefungin inhibits the trimethylguanosine synthase TGS1 to promote telomerase activity and telomere lengthening. FEBS Lett 2022; 596:42-52. [PMID: 34817067 DOI: 10.1002/1873-3468.14240] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Revised: 10/16/2021] [Accepted: 11/09/2021] [Indexed: 12/11/2022]
Abstract
Mutations in many genes that control the expression, the function, or the stability of telomerase cause telomere biology disorders (TBDs), such as dyskeratosis congenita, pulmonary fibrosis, and aplastic anemia. Mutations in a subset of the genes associated with TBDs cause reductions of the telomerase RNA moiety hTR, thus limiting telomerase activity. We have recently found that loss of the trimethylguanosine synthase TGS1 increases both hTR abundance and telomerase activity and leads to telomere elongation. Here, we show that treatment with the S-adenosylmethionine analog sinefungin inhibits TGS1 activity, increases the hTR levels, and promotes telomere lengthening in different cell types. Our results hold promise for restoring telomere length in stem and progenitor cells from TBD patients with reduced hTR levels.
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Affiliation(s)
- Alessandra Galati
- Dipartimento di Biologia e Biotecnologie, Sapienza Università di Roma, Italy
| | - Livia Scatolini
- Dipartimento di Biologia e Biotecnologie, Sapienza Università di Roma, Italy
| | - Emanuela Micheli
- Dipartimento di Biologia e Biotecnologie, Sapienza Università di Roma, Italy
| | - Francesca Bavasso
- Dipartimento di Biologia e Biotecnologie, Sapienza Università di Roma, Italy
| | - Alessandro Cicconi
- Dipartimento di Biologia e Biotecnologie, Sapienza Università di Roma, Italy
| | - Paolo Maccallini
- Dipartimento di Biologia e Biotecnologie, Sapienza Università di Roma, Italy
| | - Lu Chen
- Cancer Signaling and Epigenetics Program-Cancer Epigenetics Institute, Fox Chase Cancer Center, Philadelphia, PA, USA
| | - Caitlin M Roake
- Department of Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Stefan Schoeftner
- Dipartimento di Scienze della Vita, Università degli studi di Trieste, Italy
| | - Steven E Artandi
- Department of Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Maurizio Gatti
- Dipartimento di Biologia e Biotecnologie, Sapienza Università di Roma, Italy
- Istituto di Biologia e Patologia Molecolari del CNR, Roma, Italy
| | - Stefano Cacchione
- Dipartimento di Biologia e Biotecnologie, Sapienza Università di Roma, Italy
| | - Grazia D Raffa
- Dipartimento di Biologia e Biotecnologie, Sapienza Università di Roma, Italy
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4
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Heiland MB, Moshirfar M, Rosen DB, Ronquillo YC, Hoopes PC. Dyskeratosis Congenita and Corneal Refractive Surgery. Ophthalmol Ther 2019; 8:361-365. [PMID: 31313220 PMCID: PMC6692790 DOI: 10.1007/s40123-019-0200-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Indexed: 12/18/2022] Open
Abstract
Dyskeratosis congenita is a syndrome of bone marrow failure secondary to unstable telomeres. It is characterized by a range of mucocutaneous diseases. Due to premature telomere shortening, these patients have limbal stem cell deficiency leading to poor regeneration and maintenance of the cornea. Many of these patients will require hematopoietic stem cell transplant in their lifetime, which poses a significant risk for acute and chronic graft-versus-host disease with and without ocular manifestations. We advise against elective corneal refractive surgery in patients with dyskeratosis congenita due to the compounded and long-term risks of delayed healing secondary to limbal stem cell deficiency and ocular complications of graft-versus-host disease post-allogeneic hematopoietic stem cell transplant.
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Affiliation(s)
| | - Majid Moshirfar
- John A. Moran Eye Center, Department of Ophthalmology and Visual Sciences, University of Utah School of Medicine, Salt Lake City, UT, USA.
- Utah Lions Eye Bank, Murray, UT, USA.
- Hoopes Durrie Rivera Research Center, Hoopes Vision, Draper, UT, USA.
| | - David B Rosen
- The University of Arizona College of Medicine-Phoenix, Phoenix, AZ, USA
| | | | - Phillip C Hoopes
- Hoopes Durrie Rivera Research Center, Hoopes Vision, Draper, UT, USA
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5
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Mohanty P, Jadhav P, Shanmukhaiah C, Kumar S, Vundinti BR. A novel DKC1 gene mutation c.1177 A>T (p.I393F) in a case of dyskeratosis congenita with severe telomere shortening. Int J Dermatol 2019; 58:1468-1471. [PMID: 30868555 DOI: 10.1111/ijd.14424] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 11/19/2018] [Accepted: 02/14/2019] [Indexed: 11/28/2022]
Affiliation(s)
- Purvi Mohanty
- Department of Cytogenetics, National Institute of Immunohaematology, Mumbai, India
| | - Prajakta Jadhav
- Department of Cytogenetics, National Institute of Immunohaematology, Mumbai, India
| | | | - Selvaa Kumar
- School of Biotechnology and Bioinformatics, D. Y. Patil University, Navi Mumbai, Maharashtra, India
| | - Babu Rao Vundinti
- Department of Cytogenetics, National Institute of Immunohaematology, Mumbai, India
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6
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Clinical features of dyskeratosis congenita in mainland China: case reports and literature review. Int J Hematol 2019; 109:328-335. [DOI: 10.1007/s12185-018-02582-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 12/19/2018] [Accepted: 12/26/2018] [Indexed: 10/27/2022]
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7
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Shao Y, Feng S, Huang J, Huo J, You Y, Zheng Y. A unique homozygous WRAP53 Arg298Trp mutation underlies dyskeratosis congenita in a Chinese Han family. BMC MEDICAL GENETICS 2018. [PMID: 29514627 PMCID: PMC5842585 DOI: 10.1186/s12881-018-0549-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND Dyskeratosis congenita (DC) is an inherited telomeropathy characterized by mucocutaneous dysplasia, bone marrow failure, cancer predisposition, and other somatic abnormalities. Cells from patients with DC exhibit short telomere. The genetic basis of the majority of DC cases remains unknown. METHODS A 2 generational Chinese Han family with DC was studied using targeted capture and next-generation sequencing to identify the underlying DC-related mutations. RESULTS In this study, we identified a unique homozygous WD repeat containing antisense to TP53 (WRAP53) Arg298Trp mutation in the proband with DC and heterozygous WRAP53 Arg298Trp mutations in his asymptomatic, consanguineous parents and his sister, indicating an autosomal recessive inheritance mode. The proband with the homozygous WRAP53 Arg298Trp mutation had short telomere, classic clinical symptoms, and no response to danazol, glucocorticoid or cyclosporin A. CONCLUSIONS Thus, we reported for the first time that a unique homozygous WRAP53 mutation site underlies the development of DC.
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Affiliation(s)
- Yingqi Shao
- State Key Laboratory of Experimental Hematology, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Science & Peking Union Medical College, 288 Nanjing Road, Tianjin, 300020, People's Republic of China
| | - Sizhou Feng
- State Key Laboratory of Experimental Hematology, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Science & Peking Union Medical College, 288 Nanjing Road, Tianjin, 300020, People's Republic of China.
| | - Jinbo Huang
- State Key Laboratory of Experimental Hematology, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Science & Peking Union Medical College, 288 Nanjing Road, Tianjin, 300020, People's Republic of China
| | - Jiali Huo
- State Key Laboratory of Experimental Hematology, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Science & Peking Union Medical College, 288 Nanjing Road, Tianjin, 300020, People's Republic of China
| | - Yahong You
- State Key Laboratory of Experimental Hematology, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Science & Peking Union Medical College, 288 Nanjing Road, Tianjin, 300020, People's Republic of China
| | - Yizhou Zheng
- State Key Laboratory of Experimental Hematology, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Science & Peking Union Medical College, 288 Nanjing Road, Tianjin, 300020, People's Republic of China.
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8
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Ward SC, Savage SA, Giri N, Alter BP, Cowen EW. Progressive reticulate skin pigmentation and anonychia in a patient with bone marrow failure. J Am Acad Dermatol 2017; 77:1194-1198. [PMID: 29033247 PMCID: PMC5685909 DOI: 10.1016/j.jaad.2017.07.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 07/17/2017] [Accepted: 07/18/2017] [Indexed: 11/24/2022]
Abstract
KEY TEACHING POINTS.
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Affiliation(s)
- Suzanne C Ward
- Dermatology Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland
| | - Sharon A Savage
- Clinical Genetics Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland
| | - Neelam Giri
- Clinical Genetics Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland
| | - Blanche P Alter
- Clinical Genetics Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland
| | - Edward W Cowen
- Dermatology Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland.
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9
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Barbaro PM, Ziegler DS, Reddel RR. The wide-ranging clinical implications of the short telomere syndromes. Intern Med J 2017; 46:393-403. [PMID: 26247919 DOI: 10.1111/imj.12868] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 07/13/2015] [Indexed: 01/01/2023]
Abstract
There is an increasing number of inherited disorders in which excessive telomere shortening underlies the molecular defect, with dyskeratosis congenita (DC) being the archetypal short telomere syndrome. DC is classically described as a mucocutaneous triad of oral leukoplakia, nail dystrophy and abnormal skin pigmentation. However, excessive telomere shortening can affect almost any organ system, so the clinical manifestations are protean, including developmental delay, cerebellar hypoplasia, exudative retinopathy, aplastic anaemia, acute myeloid leukaemia, idiopathic pulmonary fibrosis, idiopathic hepatic cirrhosis, head and neck cancer and dental abnormalities, and may be multi-systemic. Undiagnosed patients may be seen by essentially any medical subspecialist. Correct diagnosis is important to ensure appropriate management, and for initiating investigations to identify affected family members. Treatment is often supportive, with transplantation offering cure for pulmonary fibrosis or bone marrow failure. Higher rates of mortality and morbidity with transplantation often require regimen alterations, underscoring the need for correct diagnosis. Short telomeres result from mutations in genes essential for telomere maintenance (e.g. genes encoding subunits of the telomerase enzyme complex). Disease severity reflects not only the severity of the defect, but also the inheritance of short telomeres, giving rise to incomplete penetrance and genetic anticipation. Attendees of the inaugural Australian Short Telomere Syndrome Conference were updated on the current scientific and clinical understanding of these disorders, and discussed the best approach for management of these patients in the Australian context. This review will include recommendations from the conference and aims to increase awareness of short telomere disorders.
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Affiliation(s)
- P M Barbaro
- Haematology Department, Sydney Children's Hospital Network (Westmead), Sydney, New South Wales, Australia.,Children's Medical Research Institute, The University of Sydney, Sydney, New South Wales, Australia
| | - D S Ziegler
- Kids Cancer Centre, Sydney Children's Hospital, Sydney, New South Wales, Australia.,School of Women's and Children's Health, University of New South Wales, Sydney, New South Wales, Australia
| | - R R Reddel
- Children's Medical Research Institute, The University of Sydney, Sydney, New South Wales, Australia
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10
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Babushok DV, Bessler M. Genetic predisposition syndromes: when should they be considered in the work-up of MDS? Best Pract Res Clin Haematol 2014; 28:55-68. [PMID: 25659730 DOI: 10.1016/j.beha.2014.11.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Accepted: 11/04/2014] [Indexed: 01/04/2023]
Abstract
Myelodysplastic syndromes (MDS) are clonal hematopoietic disorders characterized by cytopenias, ineffective hematopoiesis, myelodysplasia, and an increased risk of acute myeloid leukemia (AML). While sporadic MDS is primarily a disease of the elderly, MDS in children and young and middle-aged adults is frequently associated with underlying genetic predisposition syndromes. In addition to the classic hereditary bone marrow failure syndromes (BMFS) such as Fanconi Anemia and Dyskeratosis Congenita, in recent years there has been an increased awareness of non-syndromic familial MDS/AML predisposition syndromes such as those caused by mutations in GATA2, RUNX1, CEBPA, and SRP72 genes. Here, we will discuss the importance of recognizing an underlying genetic predisposition syndrome a patient with MDS, will review clinical scenarios when genetic predisposition should be considered, and will provide a practical overview of the common BMFS and familial MDS/AML syndromes which may be encountered in adult patients with MDS.
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Affiliation(s)
- Daria V Babushok
- Comprehensive Bone Marrow Failure Center, Division of Hematology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA; Division of Hematology, Department of Medicine, Hospital of the University of Pennsylvania, Philadelphia, PA, USA.
| | - Monica Bessler
- Comprehensive Bone Marrow Failure Center, Division of Hematology, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA; Division of Hematology, Department of Medicine, Hospital of the University of Pennsylvania, Philadelphia, PA, USA.
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11
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Fernández García MS, Teruya-Feldstein J. The diagnosis and treatment of dyskeratosis congenita: a review. J Blood Med 2014; 5:157-67. [PMID: 25170286 PMCID: PMC4145822 DOI: 10.2147/jbm.s47437] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Dyskeratosis congenita (DC) is an inherited bone marrow failure (BMF) syndrome characterized by the classic triad of abnormal skin pigmentation, nail dystrophy, and oral leukoplakia. However, patients usually develop BMF and are predisposed to cancer, with increased risk for squamous cell carcinoma and hematolymphoid neoplasms. DC is a disease of defective telomere maintenance and is heterogeneous at the genetic level. It can be inherited in X-linked, autosomal dominant, or autosomal recessive patterns. Mutations in at least ten telomere- and telomerase-associated genes have been described in DC. There are no targeted therapies for DC and patients usually die of BMF due to a deficient renewing capability of hematopoietic stem cells. Allogeneic hematopoietic stem cell transplantation is the only curative treatment for BMF.
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Affiliation(s)
- M Soledad Fernández García
- Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY, USA ; Department of Pathology, Hospital Universitario Central de Asturias, Oviedo, Spain
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12
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Savage SA. Human telomeres and telomere biology disorders. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2014; 125:41-66. [PMID: 24993697 DOI: 10.1016/b978-0-12-397898-1.00002-5] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Telomeres consist of long nucleotide repeats and a protein complex at chromosome ends essential for chromosome stability. Telomeres shorten with each cell division and thus are markers of cellular age. Dyskeratosis congenita (DC) is a cancer-prone inherited bone marrow failure syndrome caused by germ-line mutations in key telomere biology genes that result in extremely short telomeres. The triad of nail dysplasia, abnormal skin pigmentation, and oral leukoplakia is diagnostic of DC but highly variable. Patients with DC may also have but numerous other medical problems, including pulmonary fibrosis, liver abnormalities, avascular necrosis of the hips, and stenosis of the esophagus, lacrimal ducts, and/or urethra. All modes of inheritance have been reported in DC and de novo mutations are common. Broad phenotypic heterogeneity occurs within DC. Clinically severe variants of DC are Hoyeraal-Hreidarsson syndrome and Revesz syndrome. Coats plus syndrome joined the spectrum of DC with the discovery that it is caused by mutations in a telomere-capping gene. Less clinically severe variants, such as subsets of apparently isolated aplastic anemia or pulmonary fibrosis, have also been recognized. These patients may not have the DC-associated mucocutaneous triad or complicated medical features, but they do have the same underlying genetic etiology. This has led to the use of the descriptive term telomere biology disorder (TBD). This chapter will review the connection between telomere biology and human disease through the examples of DC and its related TBDs.
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Affiliation(s)
- Sharon A Savage
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
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13
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Paiva RMA, Calado RT. Telomere dysfunction and hematologic disorders. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2014; 125:133-57. [PMID: 24993701 DOI: 10.1016/b978-0-12-397898-1.00006-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Aplastic anemia is a disease in which the hematopoietic stem cell fails to adequately produce peripheral blood cells, causing pancytopenia. In some cases of acquired aplastic anemia and in inherited type of aplastic anemia, dyskeratosis congenita, telomere biology gene mutations and telomere shortening are etiologic. Telomere erosion hampers the ability of hematopoietic stem and progenitor cells to adequately replicate, clinically resulting in bone marrow failure. Additionally, telomerase mutations and short telomeres are genetic risk factors for the development of some hematologic cancers, including myelodysplastic syndrome, acute myeloid leukemia, and chronic lymphocytic leukemia.
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Affiliation(s)
- Raquel M A Paiva
- Department of Internal Medicine, University of São Paulo at Ribeirão Preto School of Medicine, Ribeirão Preto, São Paulo, Brazil
| | - Rodrigo T Calado
- Department of Internal Medicine, University of São Paulo at Ribeirão Preto School of Medicine, Ribeirão Preto, São Paulo, Brazil
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14
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Abstract
The dynamics of oral mucosa is known by its inherent defensive nature. Certain areas demand tough shield when subjected to mechanical insults. This is met by structural scaffolding material referred as cytoskeleton comprised of intracellular protein filaments called cytokeratins in the surface squames of oral epithelia. They also equally contribute towards the architecture of odontogenic apparatus and salivary gland. Differentiation of epithelial cells within stratified epithelia regulates the expression of specific keratin gene. Any mutation in, or autoantibodies to keratins, desmosomal and cornified envelope proteins is translated into genetic and acquired human disorders. Sound knowledge of structural proteins, their expression, distribution and function plays a vital role in acquainting with these disorders and their application as differentiation markers. Thus, they form an integral aid in diagnostic pathology and may be instrumental in the future interventions by gene therapy. This review focuses on basics to current updates on oral cytokeratins with an emphasis on the genetic and acquired disorders of cytokeratins with oral implications.
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Affiliation(s)
- Roopa S Rao
- Professor and Head, Department of Oral Pathology and Microbiology, Faculty of Dental Sciences, MS Ramaiah University of Applied Sciences MSRIT Post, MSR Nagar, Bangalore, Karnataka, India
| | - Shankargouda Patil
- Associate Professor, Department of Oral Pathology and Microbiology, Faculty of Dental Sciences, MS Ramaiah University of Applied Sciences MSRIT Post, MSR Nagar, Bangalore, Karnataka, India
| | - B S Ganavi
- Postgraduate Student, Department of Oral Pathology and Microbiology, Faculty of Dental Sciences, MS Ramaiah University of Applied Sciences MSRIT Post, MSR Nagar, Bangalore, Karnataka, India
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15
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Pal J, Gold JS, Munshi NC, Shammas MA. Biology of telomeres: importance in etiology of esophageal cancer and as therapeutic target. Transl Res 2013; 162:364-70. [PMID: 24090770 PMCID: PMC3834232 DOI: 10.1016/j.trsl.2013.09.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Revised: 09/05/2013] [Accepted: 09/06/2013] [Indexed: 11/17/2022]
Abstract
The purpose of this review is to highlight the importance of telomeres, the mechanisms implicated in their maintenance, and their role in the etiology as well as the treatment of human esophageal cancer. We will also discuss the role of telomeres in the maintenance and preservation of genomic integrity, the consequences of telomere dysfunction, and the various factors that may affect telomere health in esophageal tissue predisposing it to oncogenesis. There has been growing evidence that telomeres, which can be affected by various intrinsic and extrinsic factors, contribute to genomic instability, oncogenesis, as well as proliferation of cancer cells. Telomeres are the protective DNA-protein complexes at chromosome ends. Telomeric DNA undergoes progressive shortening with age leading to cellular senescence and/or apoptosis. If senescence/apoptosis is prevented as a consequence of specific genomic changes, continued proliferation leads to very short (ie, dysfunctional) telomeres that can potentially cause genomic instability, thus, increasing the risk for activation of telomere maintenance mechanisms and oncogenesis. Like many other cancers, esophageal cancer cells have short telomeres and elevated telomerase, the enzyme that maintains telomeres in most cancer cells. Homologous recombination, which is implicated in the alternate pathway of telomere elongation, is also elevated in Barrett's-associated esophageal adenocarcinoma. Evidence from our laboratory indicates that both telomerase and homologous recombination contribute to telomere maintenance, DNA repair, and the ongoing survival of esophageal cancer cells. This indicates that telomere maintenance mechanisms may potentially be targeted to make esophageal cancer cells static. The rate at which telomeres in healthy cells shorten is determined by a number of intrinsic and extrinsic factors, including those associated with lifestyle. Avoidance of factors that may directly or indirectly injure esophageal tissue including its telomeric and other genomic DNA can not only reduce the risk of development of esophageal cancer but may also have positive impact on overall health and lifespan.
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Affiliation(s)
- Jagannath Pal
- Harvard (Dana Farber) Cancer Institute, Boston, MA, USA
- VA Boston Healthcare System, Boston, MA, USA
| | - Jason S. Gold
- Harvard (Dana Farber) Cancer Institute, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
- Brigham and Women’s Hospital, Boston, MA, USA
- VA Boston Healthcare System, Boston, MA, USA
| | - Nikhil C. Munshi
- Harvard (Dana Farber) Cancer Institute, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
- VA Boston Healthcare System, Boston, MA, USA
| | - Masood A. Shammas
- Harvard (Dana Farber) Cancer Institute, Boston, MA, USA
- VA Boston Healthcare System, Boston, MA, USA
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Carrillo J, González A, Manguán-García C, Pintado-Berninches L, Perona R. p53 pathway activation by telomere attrition in X-DC primary fibroblasts occurs in the absence of ribosome biogenesis failure and as a consequence of DNA damage. Clin Transl Oncol 2013; 16:529-38. [PMID: 24065372 DOI: 10.1007/s12094-013-1112-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Accepted: 09/10/2013] [Indexed: 01/04/2023]
Abstract
BACKGROUND Dyskeratosis congenita (DC) is a rare inherited bone marrow failure syndrome with high clinical heterogeneity. Various mutations have been reported in DC patients, affecting genes that code for components of H/ACA ribonucleoproteins, proteins of the telomerase complex and components of the shelterin complex. OBJECTIVES We aim to clarify the role of ribosome biogenesis failure in senescence induction in X-DC since some studies in animal models have reported a decrease in ribosome biogenesis as a major role in the disease. METHODS Dyskerin was depleted in normal human fibroblasts by expressing two DKC1 shRNAs. Common changes in gene expression profile between these dyskerin-depleted cells and X-DC fibroblasts were analyzed. RESULTS Dyskerin depletion induced early activation of the p53 pathway probably secondary to ribosome biogenesis failure. However, the p53 pathway in the fibroblasts from X-DC patients was activated only after an equivalent number of passes to AD-DC fibroblasts, in which telomere attrition in each division rendered shorter telomeres than control fibroblasts. Indeed, no induction of DNA damage was observed in dyskerin-depleted fibroblasts in contrast to X-DC or AD-DC fibroblasts suggesting that DNA damage induced by telomere attrition is responsible for p53 activation in X-DC and AD-DC fibroblasts. Moreover, p53 depletion in senescent DC fibroblasts rescued their proliferative capacity and reverted the morphological changes produced after prolonged culture. CONCLUSIONS Our data indicate that ribosome biogenesis do not seem to play an important role in dyskeratosis congenita, conversely increasing DNA damage and activation of p53 pathway triggered by telomere shortening is the main activator of cell senescence.
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Affiliation(s)
- J Carrillo
- Instituto de Investigaciones Biomédicas de Madrid CSIC/UAM, IDIPaz (Biomarkers and Experimental Therapeutics Group), C/Arturo Duperier, 4, 28029, Madrid, Spain
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Carrillo J, Martínez P, Solera J, Moratilla C, González A, Manguán-García C, Aymerich M, Canal L, del Campo M, Dapena J, Escoda L, García-Sagredo J, Martín-Sala S, Rives S, Sevilla J, Sastre L, Perona R. High resolution melting analysis for the identification of novel mutations in DKC1 and TERT genes in patients with dyskeratosis congenita. Blood Cells Mol Dis 2012; 49:140-6. [DOI: 10.1016/j.bcmd.2012.05.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Accepted: 04/23/2012] [Indexed: 12/27/2022]
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Keller RB, Gagne KE, Usmani GN, Asdourian GK, Williams DA, Hofmann I, Agarwal S. CTC1 Mutations in a patient with dyskeratosis congenita. Pediatr Blood Cancer 2012; 59:311-4. [PMID: 22532422 PMCID: PMC3374040 DOI: 10.1002/pbc.24193] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2012] [Accepted: 04/16/2012] [Indexed: 02/06/2023]
Abstract
Dyskeratosis congenita (DC) is a rare inherited bone marrow failure syndrome caused by mutations in seven genes involved in telomere biology, with approximately 50% of cases remaining genetically uncharacterized. We report a patient with classic DC carrying a compound heterozygous mutation in the CTC1 (conserved telomere maintenance component 1) gene, which has recently implicated in the pleiotropic syndrome Coats plus. This report confirms a molecular link between DC and Coats plus and expands the genotype-phenotype complexity observed in telomere-related genetic disorders.
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Affiliation(s)
- Rachel B. Keller
- Division of Hematology/Oncology, Stem Cell Program, Children’s Hospital Boston; Department of Pediatric Oncology, Dana-Farber Cancer Institute; Harvard Medical School, Boston, MA,Harvard Stem Cell Institute, Boston, MA
| | - Katelyn E. Gagne
- Division of Hematology/Oncology, Stem Cell Program, Children’s Hospital Boston; Department of Pediatric Oncology, Dana-Farber Cancer Institute; Harvard Medical School, Boston, MA,Harvard Stem Cell Institute, Boston, MA
| | - G. Naheed Usmani
- Division of Pediatric Hematology/Oncology, University of Massachusetts Medical School, Worcester, MA
| | | | - David A. Williams
- Division of Hematology/Oncology, Stem Cell Program, Children’s Hospital Boston; Department of Pediatric Oncology, Dana-Farber Cancer Institute; Harvard Medical School, Boston, MA,Harvard Stem Cell Institute, Boston, MA
| | - Inga Hofmann
- Division of Hematology/Oncology, Stem Cell Program, Children’s Hospital Boston; Department of Pediatric Oncology, Dana-Farber Cancer Institute; Harvard Medical School, Boston, MA
| | - Suneet Agarwal
- Division of Hematology/Oncology, Stem Cell Program, Children’s Hospital Boston; Department of Pediatric Oncology, Dana-Farber Cancer Institute; Harvard Medical School, Boston, MA,Harvard Stem Cell Institute, Boston, MA,Correspondence: Suneet Agarwal, M.D., Ph.D., Children’s Hospital Boston, CLS3002, 3 Blackfan Circle, Boston, MA 02115, Phone: (617) 919-4610, Fax: (617) 919-3359,
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Abstract
PURPOSE OF REVIEW Inherited bone marrow failure syndromes (IBMFS) are a diverse set of genetic disorders characterized by the inability of the bone marrow to produce sufficient circulating blood cells. The purpose of this review is to highlight novel findings in recent years and their impact on the understanding of IBMFS. RECENT FINDINGS Mutations in over 80 different genes have been associated with the development of bone marrow failure (BMF). The products of the genes mutated in IBMFS frequently participate in housekeeping pathways, which are important for cell growth and division rather than being specific for hematopoiesis. The common theme of these pathways, when disturbed, is the activation of p53, leading to cell cycle arrest, senescence, and cell death. With continued improvement in therapy for IBMFS, late complications, such as development of malignancies, are seen more frequently. This highlights the importance of understanding the affected pathways and their roles in cancer development. SUMMARY The recent advancement of our understanding of IBMFS has come largely through the identification of the genetic lesions responsible for disease and the investigations of their pathways. Applied in clinical practice, these findings make it possible to unambiguously identify mutation carriers even before the development of BMF and exclude or confirm a suspected clinical diagnosis for many of the more common IBMFS. The further characterization of the pathways leading to IBMFS is likely to reveal novel targets for screening tests, prognostic biomarkers, and improved and specific therapeutics.
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Mason PJ, Bessler M. The genetics of dyskeratosis congenita. Cancer Genet 2011; 204:635-45. [PMID: 22285015 PMCID: PMC3269008 DOI: 10.1016/j.cancergen.2011.11.002] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2011] [Revised: 11/11/2011] [Accepted: 11/13/2011] [Indexed: 01/18/2023]
Abstract
Dyskeratosis congenita (DC) is an inherited bone marrow failure syndrome associated with characteristic mucocutaneous features and a variable series of other somatic abnormalities. The disease is heterogeneous at the genetic and clinical levels. Determination of the genetic basis of DC has established that the disease is caused by a number of genes, all of which encode products involved in telomere maintenance, either as part of telomerase or as part of the shelterin complex that caps and protects telomeres. There is overlap at the genetic and clinical levels with other, more common conditions, including aplastic anemia (AA), pulmonary fibrosis (PF), and liver cirrhosis. Although part of the spectrum of disorders known to be associated with DC, it has emerged that mutations in telomere maintenance genes can lead to the development of AA and PF in the absence of other DC features. Here we discuss the genetics of DC and its relationship to disease presentation.
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Affiliation(s)
- Philip J Mason
- Division of Hematology, Department of Pediatrics, Children's Hospital of Philadelphia, University of Pennsylvania, Philadelphia, USA.
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Nelson ND, Bertuch AA. Dyskeratosis congenita as a disorder of telomere maintenance. Mutat Res 2011; 730:43-51. [PMID: 21745483 DOI: 10.1016/j.mrfmmm.2011.06.008] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2011] [Revised: 06/16/2011] [Accepted: 06/25/2011] [Indexed: 12/11/2022]
Abstract
Since 1998, there have been great advances in our understanding of the pathogenesis of dyskeratosis congenita (DC), a rare inherited bone marrow failure and cancer predisposition syndrome with prominent mucocutaneous abnormalities and features of premature aging. DC is now characterized molecularly by the presence of short age-adjusted telomeres. Mutations in seven genes have been unequivocally associated with DC, each with a role in telomere length maintenance. These observations, combined with knowledge that progressive telomere shortening can impose a proliferative barrier on dividing cells and contribute to chromosome instability, have led to the understanding that extreme telomere shortening drives the clinical features of DC. However, some of the genes implicated in DC encode proteins that are also components of H/ACA-ribonucleoprotein enzymes, which are responsible for the post-translational modification of ribosomal and spliceosomal RNAs, raising the question whether alterations in these activities play a role in the pathogenesis of DC. In addition, recent reports suggest that some cases of DC may not be characterized by short age-adjusted telomeres. This review will highlight our current knowledge of the telomere length defects in DC and the factors involved in its development.
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Affiliation(s)
- Nya D Nelson
- Department of Molecular and Human Genetics, Texas Children's Hospital, Houston, TX 77030, USA
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