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Fonfria M, de Juan Jiménez I, Tena I, Chirivella I, Richart-Aznar P, Segura A, Sánchez-Heras AB, Martinez-Dueñas E. Prevalence and Clinicopathological Characteristics of Moderate and High-Penetrance Genes in Non-BRCA1/2 Breast Cancer High-Risk Spanish Families. J Pers Med 2021; 11:jpm11060548. [PMID: 34204722 PMCID: PMC8231620 DOI: 10.3390/jpm11060548] [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: 04/26/2021] [Revised: 06/09/2021] [Accepted: 06/10/2021] [Indexed: 01/10/2023] Open
Abstract
(1) Background: Over the last decade, genetic counseling clinics have moved from single-gene sequencing to multigene panel sequencing. Multiple genes related to a moderate risk of breast cancer (BC) have emerged, although many questions remain regarding the risks and clinical features associated with these genes. (2) Methods: Ninety-six BC index cases (ICs) with high-risk features for hereditary breast and ovarian cancer (HBOC) and with a previous uninformative result for BRCA1/2 were tested with a panel of 41 genes associated with BC risk. The frequency of pathogenic variants (PVs) was related to the clinical characteristics of BC. (3) Results: We detected a PV rate of 13.5% (excluding two cases each of BRCA1 and MUTYH). Among the 95 assessed cases, 17 PVs were identified in 16 ICs, as follows: BRCA1 (n = 2), CHEK2 (n = 3), ATM (n = 5), MUTYH (n = 2), TP53 (n = 2), BRIP1 (n = 1), CASP8 (n = 1), and MSH2 (n = 1). We also identified a novel loss-of-function variant in CASP8, a candidate gene for increased BC risk. There was no evidence that the clinical characteristics of BC might be related to a higher chance of identifying a PV. (4) Conclusions: In our cohort, which was enriched with families with a high number of BC cases, a high proportion of mutations in ATM and CHEK2 were identified. The clinical characteristics of BC associated with moderate-risk genes were different from those related to BRCA1/2 genes.
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Affiliation(s)
- Maria Fonfria
- Cancer Genetic Counseling Unit, Medical Oncology Department, Castellon Provincial Hospital, 12002 Castellon, Spain; (M.F.); (I.T.); (E.M.-D.)
| | - Inmaculada de Juan Jiménez
- Molecular Biology Unit, Service of Clinical Analysis, La Fe University Hospital, 46026 Valencia, Spain
- Correspondence: ; Tel.: +34-961244587
| | - Isabel Tena
- Cancer Genetic Counseling Unit, Medical Oncology Department, Castellon Provincial Hospital, 12002 Castellon, Spain; (M.F.); (I.T.); (E.M.-D.)
| | - Isabel Chirivella
- Medical Oncology Department, INCLIVA Biomedical Research Institute, University of Valencia, 46001 Valencia, Spain;
| | - Paula Richart-Aznar
- Cancer Genetic Counseling Unit, Medical Oncology Department, La Fe University Hospital, 46026 Valencia, Spain; (P.R.-A.); (A.S.)
| | - Angel Segura
- Cancer Genetic Counseling Unit, Medical Oncology Department, La Fe University Hospital, 46026 Valencia, Spain; (P.R.-A.); (A.S.)
| | - Ana Beatriz Sánchez-Heras
- Cancer Genetic Counseling Unit, Medical Oncology Department, Elche University Hospital, 03203 Elche, Spain;
| | - Eduardo Martinez-Dueñas
- Cancer Genetic Counseling Unit, Medical Oncology Department, Castellon Provincial Hospital, 12002 Castellon, Spain; (M.F.); (I.T.); (E.M.-D.)
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2
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Global perspectives on primary immune deficiency diseases. STIEHM'S IMMUNE DEFICIENCIES 2020. [PMCID: PMC7258797 DOI: 10.1016/b978-0-12-816768-7.00054-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Amirifar P, Ranjouri MR, Yazdani R, Abolhassani H, Aghamohammadi A. Ataxia-telangiectasia: A review of clinical features and molecular pathology. Pediatr Allergy Immunol 2019; 30:277-288. [PMID: 30685876 DOI: 10.1111/pai.13020] [Citation(s) in RCA: 98] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2018] [Revised: 12/29/2018] [Accepted: 12/30/2018] [Indexed: 01/09/2023]
Abstract
Ataxia-telangiectasia (A-T) is an autosomal recessive primary immunodeficiency (PID) disease that is caused by mutations in ataxia-telangiectasia mutated (ATM) gene encoding a serine/threonine protein kinase. A-T patients represent a broad range of clinical manifestations including progressive cerebellar ataxia, oculocutaneous telangiectasia, variable immunodeficiency, radiosensitivity, susceptibility to malignancies, and increased metabolic diseases. This congenital disorder has phenotypic heterogeneity, and the severity of symptoms varies in different patients based on severity of mutations and disease progression. The principal role of nuclear ATM is the coordination of cellular signaling pathways in response to DNA double-strand breaks, oxidative stress, and cell cycle checkpoint. The pathogenesis of A-T is not limited to the role of ATM in the DNA damage response (DDR) pathway, and it has other functions mainly in the hematopoietic cells and neurons. ATM adjusts the functions of organelles such as mitochondria and peroxisomes and also regulates angiogenesis and glucose metabolisms. However, ATM has other functions in the cells (especially cell viability) that need further investigations. In this review, we described functions of ATM in the nucleus and cytoplasm, and also its association with some disorder formation such as neurologic, immunologic, vascular, pulmonary, metabolic, and dermatologic complications.
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Affiliation(s)
- Parisa Amirifar
- Medical Genetics Department, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Reza Ranjouri
- Molecular Medicine and Genetics Department, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Reza Yazdani
- Research Center for Immunodeficiencies, Pediatrics Center of Excellence, Children's Medical Center, Tehran, Iran
- University of Medical Science, Tehran, Iran
| | - Hassan Abolhassani
- Research Center for Immunodeficiencies, Pediatrics Center of Excellence, Children's Medical Center, Tehran, Iran
- University of Medical Science, Tehran, Iran
- Division of Clinical Immunology, Department of Laboratory Medicine, Karolinska Institute at Karolinska University Hospital Huddinge, Stockholm, Sweden
| | - Asghar Aghamohammadi
- Research Center for Immunodeficiencies, Pediatrics Center of Excellence, Children's Medical Center, Tehran, Iran
- University of Medical Science, Tehran, Iran
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4
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Glen WB, Peterseim MMW, Badilla R, Znoyko I, Bourg A, Wilson R, Hardiman G, Wolff D, Martinez J. A high prevalence of biallelic RPE65 mutations in Costa Rican children with Leber congenital amaurosis and early-onset retinal dystrophy. Ophthalmic Genet 2019; 40:110-117. [PMID: 30870047 DOI: 10.1080/13816810.2019.1582069] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
BACKGROUND Leber congenital amaurosis (LCA) and early-onset retinal dystrophy (EORD), are primary causes of inherited childhood blindness. Both are autosomal recessive diseases, with mutations in more than 25 genes explaining approximately ~70% of cases. However, the genetic cause for many cases remains unclear. Sequencing studies from genetically isolated populations with increased prevalence of a disorder has proven useful for rare variant studies, making Costa Rica an ideal place to study LCA/EORD genetics. MATERIALS AND METHODS Twenty-eight affected children (25 LCA, three EORD) and their immediate family members, totaling 52 individuals (30 affected) from 22 families, were sequenced. Whole exome sequencing was performed on all affected individuals. Available parents were analyzed either by whole exome sequencing (WES) or Sanger sequencing to determine transmission. RESULTS All affected individuals demonstrated compound heterozygous or homozygous mutations in known Inherited Retinal Disease (IRD) associated genes. Twelve variants were identified in at least one individual in three genes, RDH12, RPE65, and USH2A. Four recurrent RPE65 mutations were observed in 97% of individuals and 95% of families. All patients with LCA and two of the three individuals with EORD had biallelic mutations in RPE65; one child with EORD had a homozygous RDH12 mutation. CONCLUSIONS These data suggest that the majority of LCA/EORD in Costa Rica is due to four founder mutations in RPE65 which have been maintained in this genetically isolated population. This finding is of great clinical significance due to the availability of gene therapy recently approved in the US and European Union for patients with biallelic RPE65 defects.
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Affiliation(s)
- W Bailey Glen
- a Pathology and Laboratory Medicine , Medical University of South Carolina.,b Center for Genomic Medicine , Medical University of South Carolina
| | | | - Ramses Badilla
- d Genetics and Metabolism , National Children's Hospital , San José , Costa Rica.,e Caja Costarricense del Seguro Social
| | - Iya Znoyko
- a Pathology and Laboratory Medicine , Medical University of South Carolina
| | - Andre Bourg
- f Department of Medicine , Medical University of South Carolina
| | - Robert Wilson
- a Pathology and Laboratory Medicine , Medical University of South Carolina.,b Center for Genomic Medicine , Medical University of South Carolina
| | - Gary Hardiman
- b Center for Genomic Medicine , Medical University of South Carolina.,f Department of Medicine , Medical University of South Carolina.,g Institute for Global Food Security , Queen's University Belfast
| | - Daynna Wolff
- a Pathology and Laboratory Medicine , Medical University of South Carolina
| | - Joaquin Martinez
- e Caja Costarricense del Seguro Social.,h Division of Ophthalmology , National Children's Hospital , San José , Costa Rica
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5
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Molecular and Functional Characterization of a Cohort of Spanish Patients with Ataxia-Telangiectasia. Neuromolecular Med 2016; 19:161-174. [DOI: 10.1007/s12017-016-8440-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Accepted: 09/10/2016] [Indexed: 10/21/2022]
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6
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Olgaç A, Tümer L, Boyunağa Ö, Kızılkaya M, Hasanoğlu A. Diagnostic dilemma: osteopetrosis with superimposed rickets causing neonatal hypocalcemia. J Trop Pediatr 2015; 61:146-50. [PMID: 25673572 DOI: 10.1093/tropej/fmv001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Osteopetrosis is a rare genetic condition of reduced osteoclastic bone resorption which causes defective bone remodeling and skeletal sclerosis during growth, having effects on many organs and tissues. Mutation of T-cell immune regulator 1 (TCRG1) gene is the most common genetic defect leading to osteopetrosis, with poor prognosis. The autosomal recessive form presents in the infantile period (also known as malignant infantile osteopetrosis--MIOP), and is characterized by fractures, short stature, hepatosplenomegaly, compressive neuropathies, hypocalcemia and pancytopenia. Being a rare disease with non-specific clinical manifestations, the diagnosis is difficult and usually delayed. Rickets is a characteristic feature of MIOP which results from the defect in osteoclasts to provide a normal Ca/P balance resulting in the poor mineralization of the osteoid. Various treatment options have been suggested for osteopetrosis, but hematopoietic stem cell transplantation still remains the only curative treatment option presently. The authors report the case of a 46-day-old girl with late-onset neonatal hypocalcemia and rickets that was later diagnosed as osteopetrosis. This case report emphasizes that infantile osteopetrosis is an important cause of neonatal hypocalcemia. As irreversible complications develop within the first months of life, immediate diagnosis and early intervention are crucial and may be life-saving.
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Affiliation(s)
- Asburçe Olgaç
- Department of Pediatric Metabolism and Nutrition, Gazi University, Ankara, Turkey
| | - Leyla Tümer
- Department of Pediatric Metabolism and Nutrition, Gazi University, Ankara, Turkey
| | - Öznur Boyunağa
- Department of Radiology, Gazi University, Ankara, Turkey
| | | | - Alev Hasanoğlu
- Department of Pediatric Metabolism and Nutrition, Gazi University, Ankara, Turkey
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Termsarasab P, Yang AC, Frucht SJ. Myoclonus in ataxia-telangiectasia. TREMOR AND OTHER HYPERKINETIC MOVEMENTS (NEW YORK, N.Y.) 2015; 5:298. [PMID: 25793145 PMCID: PMC4365056 DOI: 10.7916/d88p5z9x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/02/2015] [Accepted: 02/03/2015] [Indexed: 01/02/2023]
Abstract
Background Various movement disorders can be found in ataxia–telangiectasia (AT), including ataxia, dystonia, chorea, and myoclonus, but myoclonus has rarely been described as the predominant feature in AT. Case Report We report two AT patients with prominent myoclonus, illustrating an unusual presentation of this disorder. Sequencing of the ATM gene in the first patient revealed a homozygous truncating mutation, c.5908C>T (p.Q1970*) in exon 38 of the ATM gene, which has been previously reported as a founder mutation in the Costa Rican population. Discussion Myoclonus can be a predominant or presenting feature in AT, even without dystonia.
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Affiliation(s)
- Pichet Termsarasab
- Movement Disorder Division, Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Amy C Yang
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Steven J Frucht
- Movement Disorder Division, Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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Gatti RA. SMRT compounds correct nonsense mutations in primary immunodeficiency and other genetic models. Ann N Y Acad Sci 2012; 1250:33-40. [PMID: 22364446 DOI: 10.1111/j.1749-6632.2012.06467.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Within less than 10 years after the realization of the double helix of DNA, the ability of aminoglycosides to influence the misreading or readthrough of premature termination codons was discovered. It took another three decades to clone and sequence disease genes and appreciate the similarity of mutation spectra for most inborn errors. Nonsense mutations once again have become the target of readthrough compounds. In this brief review, we trace the development in our laboratory of the next generation of readthrough agents, small molecule readthrough (SMRT) drug-like chemicals, and assays for comparing their in vitro activity. Possible mechanisms of action and potential clinical applications are considered.
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Affiliation(s)
- Richard A Gatti
- David Geffen/UCLA School of Medicine, Department of Pathology and Laboratory Medicine, and Human Genetics, Los Angeles, California 90095-1732, USA.
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9
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Perlman SL, Boder Deceased E, Sedgewick RP, Gatti RA. Ataxia-telangiectasia. HANDBOOK OF CLINICAL NEUROLOGY 2012; 103:307-32. [PMID: 21827897 DOI: 10.1016/b978-0-444-51892-7.00019-x] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Susan L Perlman
- David Geffen School of Medicine at the University of California at Los Angeles, CA 90095, USA.
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10
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Nakamura K, Du L, Tunuguntla R, Fike F, Cavalieri S, Morio T, Mizutani S, Brusco A, Gatti RA. Functional characterization and targeted correction of ATM mutations identified in Japanese patients with ataxia-telangiectasia. Hum Mutat 2011; 33:198-208. [PMID: 22006793 DOI: 10.1002/humu.21632] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Accepted: 09/15/2011] [Indexed: 01/12/2023]
Abstract
A recent challenge for investigators studying the progressive neurological disease ataxia-telangiectasia (A-T) is to identify mutations whose effects might be alleviated by mutation-targeted therapies. We studied ATM mutations in eight families of Japanese A-T patients (JPAT) and were able to identify all 16 mutations. The probands were compound heterozygotes in seven families, and one (JPAT2) was homozygous for a frameshift mutation. All mutations--four frameshift, two nonsense, four large genomic deletions, and six affecting splicing--were novel except for c.748C>T found in family JPAT6 and c.2639-384A>G found in family JPAT11/12. Using an established lymphoblastoid cell line (LCL) of patient JPAT11, ATM protein was restored to levels approaching wild type by exposure to an antisense morpholino oligonucleotide designed to correct a pseudoexon splicing mutation. In addition, in an LCL from patient JPAT8/9, a heterozygous carrier of a nonsense mutation, ATM levels could also be partially restored by exposure to readthrough compounds (RTCs): an aminoglycoside, G418, and a novel small molecule identified in our laboratory, RTC13. Taken together, our results suggest that screening and functional characterization of the various sorts of mutations affecting the ATM gene can lead to better identification of A-T patients who are most likely to benefit from rapidly developing mutation-targeted therapeutic technologies.
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Affiliation(s)
- Kotoka Nakamura
- Department of Pathology and Laboratory Medicine, UCLA School of Medicine, Los Angeles, California 90095-1732, USA
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11
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Graña B, Fachal L, Darder E, Balmaña J, Ramón Y Cajal T, Blanco I, Torres A, Lázaro C, Diez O, Alonso C, Santamariña M, Velasco A, Teulé A, Lasa A, Blanco A, Izquierdo A, Borràs J, Gutiérrez-Enríquez S, Vega A, Brunet J. Germline ATM mutational analysis in BRCA1/BRCA2 negative hereditary breast cancer families by MALDI-TOF mass spectrometry. Breast Cancer Res Treat 2011; 128:573-9. [PMID: 21445571 DOI: 10.1007/s10549-011-1462-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Accepted: 03/15/2011] [Indexed: 12/31/2022]
Abstract
Biallelic inactivation of ATM gene causes the rare autosomal recessive disorder Ataxia-telangiectasia (A-T). Female relatives of A-T patients have a two-fold higher risk of developing breast cancer (BC) compared with the general population. ATM mutation carrier identification is laborious and expensive, therefore, a more rapid and directed strategy for ATM mutation profiling is needed. We designed a case-control study to determine the prevalence of 32 known ATM mutations causing A-T in Spanish population in 323 BRCA1/BRCA2 negative hereditary breast cancer (HBC) cases and 625 matched Spanish controls. For the detection of the 32 ATM mutations we used the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry technique. We identified one patient carrier of the c.8264_8268delATAAG ATM mutation. This mutation was not found in the 625 controls. These results suggest a low frequency of these 32 A-T causing mutations in the HBC cases in our population. Further case-control studies analyzing the entire coding and flanking sequences of the ATM gene are warranted in Spanish BC patients to know its implication in BC predisposition.
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Affiliation(s)
- B Graña
- High Risk and Cancer Prevention Unit, Vall d'Hebron Institute of Oncology, University Hospital Vall d'Hebron, P. Vall d'Hebron 119-129, 08035 Barcelona, Spain.
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12
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Villa A, Guerrini MM, Cassani B, Pangrazio A, Sobacchi C. Infantile malignant, autosomal recessive osteopetrosis: the rich and the poor. Calcif Tissue Int 2009; 84:1-12. [PMID: 19082854 DOI: 10.1007/s00223-008-9196-4] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2008] [Accepted: 11/07/2008] [Indexed: 02/06/2023]
Abstract
Human recessive osteopetrosis (ARO) represents a group of diseases in which, due to a defect in osteoclasts, bone resorption is prevented. The deficit could arise either from failure in osteoclast differentiation or from inability to perform resorption by mature, multinucleated, but nonfunctional cells. Historically, osteopetrosis due to both these mechanisms was found in spontaneous and artificially created mouse mutants, but the first five genes identified in human ARO (CA-II, TCIRG1, ClCN7, OSTM1, and PLEKHM1) were all involved in the effector function of mature osteoclasts, being linked to acidification of the cell/bone interface or to intracellular processing of the resorbed material. Differentiation defects in human ARO have only recently been described, following the identification of mutations in both RANKL and RANK, which define a new form of osteoclast-poor ARO, as expected from biochemical, cellular, and animal studies. The molecular dissection of ARO has prognostic and therapeutic implications. RANKL-dependent patients, in particular, represent an interesting subset which could benefit from mesenchymal cell transplant and/or administration of soluble RANKL cytokine.
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Affiliation(s)
- Anna Villa
- Istituto di Tecnologie Biomediche, CNR, via Cervi 93, Segrate, Italy.
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13
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Du L, Lai CH, Concannon P, Gatti RA. Rapid screen for truncating ATM mutations by PTT-ELISA. Mutat Res 2008; 640:139-44. [PMID: 18321536 DOI: 10.1016/j.mrfmmm.2008.01.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2007] [Revised: 12/29/2007] [Accepted: 01/10/2008] [Indexed: 11/19/2022]
Abstract
Mutations in the ataxia-telangiectasia mutated (ATM) gene are responsible for the autosomal recessive genetic disorder, ataxia-telangiectasia (A-T). Approximately 80% of ATM mutations found in A-T patients results in truncations, which can be detected by Protein Truncation Test (PTT). Conventional PTT uses SDS-PAGE electrophoresis to detect mobility of radiolabeled truncated protein fragments. In this study, we developed a non-radioactive Protein Truncation Test which utilizes an enzyme-linked immunosorbent assay (PTT-ELISA) to detect ATM mutations in eight overlapping fragments. N- and C-terminal epitopes (c-myc and V5, respectively) were introduced into transcription/translation products, which could then be detected by Sandwich ELISA. Using this assay, we screened 9 newly diagnosed A-T patients consecutively. Of the 18 expected mutations, 14 truncating mutations were independently identified by cDNA direct sequencing and/or DNA dHPLC analysis. PTT-ELISA detected all of these 14. Four mutations were novel. The PTT-ELISA provides a rapid method for detecting truncating mutations in large genes and should be considered prior to using more laborious or costly methods, such as direct sequencing.
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Affiliation(s)
- Liutao Du
- Department of Pathology and Laboratory Medicine, The David Geffen School of Medicine at UCLA, CA 90095, United States
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14
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Babaei M, Mitui M, Olson ER, Gatti RA. ATM haplotypes and associated mutations in Iranian patients with ataxia–telangiectasia: recurring homozygosity without a founder haplotype. Hum Genet 2005; 117:101-6. [PMID: 15843990 DOI: 10.1007/s00439-005-1254-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2004] [Accepted: 01/05/2005] [Indexed: 12/22/2022]
Abstract
Ataxia-telangiectasia (A-T) is an autosomal recessive disorder caused by mutations in the ATM gene. The ATM gene spans more than 150 kb at chromosomal region 11q23.1 and encodes a product of 3,056 amino acids. The ATM protein is a serine/threonine protein kinase and is involved in oxidative stress, cell cycle control, and DNA repair. We analyzed the 11q22-23 haplotypes and associated mutations of 16 Iranian families. We utilized standardized short tandem repeat (STR) haplotypes to enhance mutation identification. In addition to the STR markers, single-nucleotide polymorphism haplotypes were determined, using three critical polymorphisms. The entire gene was screened sequentially by protein truncation testing, single-strand conformation polymorphism, and denaturing high-performance liquid chromatography to identify the disease-causing mutations. Of the expected 32 mutations, 25 (78%) were identified. All but two mutations led to a truncated or null form of the ATM protein (nonsense, splice site, or frameshift). Twelve mutations were identified for 15 haplotypes. Five mutations were novel. Mutations were located throughout the entire gene, with no clustering. Despite the absence of an Iranian founder mutation, three-fourths of the families were homozygous, suggesting that many undetected ATM mutations still exist in Iran. This study establishes a database for Iranian A-T families, and extends the global spectrum of ATM mutations.
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Affiliation(s)
- Mahnoush Babaei
- The David Geffen School of Medicine, Department of Pathology, University of California, 675 Young Drive South, Los Angeles, CA 90095-1732, USA
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Coutinho G, Mitui M, Campbell C, Costa Carvalho BT, Nahas S, Sun X, Huo Y, Lai CH, Thorstenson Y, Tanouye R, Raskin S, Kim CA, Llerena J, Gatti RA. Five haplotypes account for fifty-five percent of ATM mutations in Brazilian patients with ataxia telangiectasia: seven new mutations. Am J Med Genet A 2004; 126A:33-40. [PMID: 15039971 DOI: 10.1002/ajmg.a.20570] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We have studied the molecular genetics of 27 Brazilian families with ataxia telangiectasia (AT). Five founder effect haplotypes accounted for 55.5% of the families. AT is an autosomal recessive disorder of childhood onset characterized by progressive cerebellar ataxia, ocular apraxia, telangiectasia, immunodeficiency, radiation sensitivity, chromosomal instability, and predisposition to cancer. The ATM gene spans more than 150 kb on chromosome region 11q23.1 and encodes a product of 3056 amino acids. The ATM protein is a member of the phosphatidylinositol 3-kinase (PI-3K) family of proteins and is involved in cell cycle control and DNA repair pathways. DNA was isolated from lymphoblastoid cell lines and haplotyped using four STR markers (D11S1818, NS22, D11S2179, D11S1819) within and flanking the ATM gene; all allele sizes were standardized in advance. In addition to the STR haplotypes, SNP haplotypes were determined using 10 critical polymorphisms. The entire gene was screened sequentially by protein truncation testing (PTT), single strand conformation polymorphism (SSCP), and then denaturing high performance liquid chromatography (dHPLC) to identify the disease-causing mutations. Of the expected 54 mutations, 50 were identified. All mutations but one, led to a truncated or null form of the ATM protein (nonsense, splice site, or frameshift). Five families (18.5%) carried a deletion of 3450nt (from IVS28 to Ex31), making this one of the two most common Brazilian mutations. Mutations were located throughout the entire gene, with no clustering or hotspots. Standardized STR haplotype analysis greatly enhanced the efficiency of mutation screening.
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Affiliation(s)
- Gabriela Coutinho
- Department of Pathology and Laboratory Medicine, The David Geffen School of Medicine, Los Angeles, California 90095-1732, USA
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16
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Eng L, Coutinho G, Nahas S, Yeo G, Tanouye R, Babaei M, Dörk T, Burge C, Gatti RA. Nonclassical splicing mutations in the coding and noncoding regions of the ATM Gene: maximum entropy estimates of splice junction strengths. Hum Mutat 2004; 23:67-76. [PMID: 14695534 DOI: 10.1002/humu.10295] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Ataxia-telangiectasia (A-T) is an autosomal recessive neurological disorder caused by mutations in the ATM gene. Classical splicing mutations (type I) delete entire exons during pre-mRNA splicing. In this report, we describe nine examples of nonclassical splicing mutations in 12 A-T patients and compare cDNA changes to estimates of splice junction strengths based on maximum entropy modeling. These mutations fall into three categories: pseudoexon insertions (type II), single nucleotide changes within the exon (type III), and intronic changes that disrupt the conserved 3' splice sequence and lead to partial exon deletion (type IV). Four patients with a previously reported type II (pseudoexon) mutation all shared a common founder haplotype. Three patients with apparent missense or silent mutations actually had type III aberrant splicing and partial deletion of an exon. Five patients had type IV mutations that could have been misinterpreted as classical splicing mutations. Instead, their mutations disrupt a splice site and use another AG splice site located nearby within the exon; they lead to partial deletions at the beginning of exons. These nonclassical splicing mutations create frameshifts that result in premature termination codons. Without screening cDNA or using accurate models of splice site strength, the consequences of these genomic mutations cannot be reliably predicted. This may lead to further misinterpretation of genotype-phenotype correlations and may subsequently impact upon gene-based therapeutic approaches.
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Affiliation(s)
- Laura Eng
- Department of Pathology and Laboratory Medicine, The David Geffen School of Medicine at UCLA, Los Angeles, California 90095-1732, USA
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17
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Chun HH, Sun X, Nahas SA, Teraoka S, Lai CH, Concannon P, Gatti RA. Improved diagnostic testing for ataxia-telangiectasia by immunoblotting of nuclear lysates for ATM protein expression. Mol Genet Metab 2003; 80:437-43. [PMID: 14654357 DOI: 10.1016/j.ymgme.2003.09.008] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The laboratory diagnosis of ataxia-telangiectasia (A-T) currently relies upon measurement of serum alphafetoprotein (AFP) and cellular sensitivity to ionizing radiation. A previous report suggests that immunoblotting of whole cell lysates from lymphoblastoid cell lines (LCLs) might be informative for diagnosis. To further evaluate this possibility, and improve sensitivity, we performed immunoblotting for ATM protein on nuclear lysates of 71 consecutive radiosensitive LCLs that were established from patients with clinical features suggestive of A-T. Fifty-two LCLs (73%) contained no detectable ATM protein, with a representative sample (N=25) testing negative for ATM kinase activity, having at least one ATM mutation, and having elevated AFP levels; these results confirmed the diagnosis. Seventeen LCLs (24%) expressed intermediate or normal levels of ATM protein and exhibited normal ATM kinase activity; follow-up studies failed to detect ATM mutations and AFP levels were normal in all but three. Of the remaining two radiosensitive LCLs, one had 35% of normal protein with normal kinase activity and no ATM mutations. The other LCL had 9% of normal protein, with intermediate levels of kinase activity, a homozygous missense ATM mutation, and elevated AFP. Our data suggest that it is very uncommon to encounter bonafide A-T patients with more than trace amounts of ATM protein. We conclude that immunoblotting for ATM protein is of higher specificity for diagnosing A-T than radiosensitivity testing. In addition, we have documented in vitro radiosensitivity in other patients who share some clinical features with A-T.
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Affiliation(s)
- Helen H Chun
- Department of Pathology, The David Geffen School of Medicine at UCLA, Los Angeles, CA 90095-1732, USA
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18
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Abstract
Inherited biallelic mutations of the ATM (ataxia-telangiectasia mutated) gene cause ataxia-telangiectasia, a rare autosomal recessive disorder associated with a high incidence of childhood leukaemias and lymphomas, suggesting that ATM gene alterations may be involved in lymphomagenesis. Loss of heterozygosity at 11q22-23 (location of the ATM gene) is a frequent event in sporadic lymphoid tumours, and several studies have reported a high prevalence of ATM gene alterations in diverse sporadic lymphoproliferative disorders, adding evidence to the postulated contribution of ATM in the pathogenesis of these tumours. This mini-review will summarize the recently published data concerning the ATM gene in sporadic lymphoid malignancies and will discuss the apparent paradox between the predominance of nonsense mutations observed in patient with ataxia-telangiectasia and the high proportion of missense alterations found in sporadic lymphoid tumours.
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Affiliation(s)
- F Gumy-Pause
- Department of Pediatrics, Hematology/Oncology Unit, University Hospital of Geneva, Switzerland.
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19
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Abstract
Much progress has been made in the early diagnosis of ataxia-telangiectasia since the gene was cloned in 1995, A clinical diagnosis can now be confirmed by radiosensitivity testing (colony survival assay), immunoblotting, and mutation detection. The diagnostic value of serum alpha-fetoprotein levels and radiosensitivity has been reevaluated using patients with diagnoses based on the presence of mutations in the ATM gene and the absence of ATM protein in nuclear extracts. Little progress has been made in treating the progressive ataxia.
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Affiliation(s)
- Susan Perlman
- Department of Neurology, Mental Retardation Research Center, UCLA School of Medicine, Los Angeles, CA 90095-1732, USA
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20
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Mitui M, Campbell C, Coutinho G, Sun X, Lai CH, Thorstenson Y, Castellvi-Bel S, Fernandez L, Monros E, Carvalho BTC, Porras O, Fontan G, Gatti RA. Independent mutational events are rare in the ATM gene: haplotype prescreening enhances mutation detection rate. Hum Mutat 2003; 22:43-50. [PMID: 12815592 DOI: 10.1002/humu.10232] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Mutations in the ATM gene are responsible for the autosomal recessive disorder ataxia-telangiectasia (A-T). Many different mutations have been identified using various techniques, with detection efficiencies ranging from 57 to 85%. In this study, we employed short tandem repeat (STR) haplotypes to enhance mutation identification in 55 unrelated A-T families of Iberian origin (20 Spanish, 17 Brazilian, and 18 Hispanic-American); we were able to identify 95% of the expected mutations. Allelic sizes were standardized based on a reference sample (CEPH 1347-2). Subsequent mutation screening was performed by PTT, SSCP, and DHPLC, and abnormal regions were sequenced. Many STR haplotypes were found within each population and six haplotypes were observed across several of these populations. Single nucleotide polymorphism (SNP) haplotypes further suggested that most of these common mutations are ancestrally related, and not hot spots. However, two mutations (8977C>T and 8264_8268delATAAG) may indeed be recurring mutational events. Common haplotypes were present in 13 of 20 Spanish A-T families (65%), in 11 of 17 Brazilian A-T families (65%), and, in contrast, in only eight of 18 Hispanic-American families (44%). Three mutations were identified that would be missed by conventional screening strategies. In all, 62 different mutations (28 not previously reported) were identified and their associated haplotypes defined, thereby establishing a new database for Iberian A-T families, and extending the spectrum of worldwide ATM mutations.
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Affiliation(s)
- Midori Mitui
- Department of Pathology and Laboratory Medicine, The David Geffen School of Medicine, Los Angeles, California 90095-1732, USA
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21
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Campbell C, Mitui M, Eng L, Coutinho G, Thorstenson Y, Gatti RA. ATM mutations on distinct SNP and STR haplotypes in ataxia-telangiectasia patients of differing ethnicities reveal ancestral founder effects. Hum Mutat 2003; 21:80-5. [PMID: 12497634 DOI: 10.1002/humu.10156] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Due to the large size (150 kb) of the ataxia-telangiectasia mutated (ATM) gene and the existence of over 400 mutations, identifying mutations in patients with ataxia-telangiectasia (A-T) is labor intensive. We compared the SNP and STR haplotypes of A-T patients from varying ethnicities who were carrying common ATM mutations. We used SSCP to determine SNP haplotypes. To our surprise, all of the most common ATM mutations in our large multiethnic cohort were associated with specific SNP haplotypes, whereas the STR haplotypes varied, suggesting that ATM mutations predated STR haplotypes but not SNP haplotypes. We conclude that these frequently observed ATM mutations are not hot spots, but have occurred only once and spread with time to different ethnic populations. More generally, a combination of SNP and STR haplotyping could be used as a screening strategy for identifying mutations in other large genes by first determining the ancestral SNP and STR haplotypes in order to identify specific founder mutations. We estimate this approach will identify approximately 30% of mutations in A-T patients across all ethnic groups.
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Affiliation(s)
- Catarina Campbell
- Department of Pathology, University of California Los Angeles, Los Angeles, California 90095-1732, USA
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22
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Abstract
The general population of Costa Rica has sometimes been considered to be the product of an amalgamation of groups of diverse origin. To determine the magnitude of accumulated admixture since Spanish colonization, 11 classic genetic markers were analyzed in a total of 2196 individuals originating from five distinct regions of the country. A maximum likelihood approach was used. The proportions of genes of European, Amerindian and African ancestry were found to be 61%, 30% and 9% of the total population, respectively. Variation was observed at a regional level, with an increased European influence in the North (66%) and Central (65%) regions. Meanwhile an increase in Amerindian ancestry was found in the South (38%), and a higher incidence in the contribution of African genes was detected in the coastal regions (13% in the Atlantic and 14% in the North Pacific). A principal component (PC) analysis showed that 76% of the existing variability can be explained by the first two PCs, which is in agreement with the variations observed in the admixture process by geographic area. It has been concluded that the Costa Rican population is truly trihybrid, similar to populations in other Latin American countries; however, it differs from them fundamentally by the proportion of gene flow from ancestral populations.
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Affiliation(s)
- B Morera
- Unitat de Biologia Evolutiva, Facultad de Ciencias de la Salut i de la Vida, Universitat Pompeu Fabra, Barcelona, Spain.
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23
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Abstract
Ataxia telangiectasia (AT) is a rare multisystem, autosomal, recessive disease characterised by neuronal degeneration, genome instability, and an increased risk of cancer. Approximately 10% of AT homozygotes develop cancer, mostly of the lymphoid system. Lymphoid malignancies in patients with AT are of both B cell and T cell origin, and include Hodgkin's lymphoma, non-Hodgkin's lymphoma, and several forms of leukaemia. The AT locus was mapped to the chromosomal region 11q22-23 using genetic linkage analysis in the late 1980s and the causative gene was identified by positional cloning several years later. The ATM gene encodes a large protein that belongs to a family of kinases possessing a highly conserved C-terminal kinase domain related to the phosphatidylinositol 3-kinase domain. Members of this kinase family have been shown to function in DNA repair and cell cycle checkpoint control following DNA damage. Recent studies indicate that ATM is activated primarily in response to double strand breaks and may be considered a caretaker of the genome. Most mutations in ATM result in truncation and destabilisation of the protein, but certain missense and splicing errors have been shown to produce a less severe phenotype. AT heterozygotes have a slightly increased risk of breast cancer. Atm deficient mice exhibit many of the symptoms found in patients with AT and have a high frequency of thymic lymphoma. The association between mutation of the ATM gene and a high incidence of lymphoid malignancy in patients with AT, together with the development of lymphoma in Atm deficient mice, supports the proposal that inactivation of the ATM gene may be of importance in the pathogenesis of sporadic lymphoid malignancy. Loss of heterozygosity at 11q22-23 (the location of the ATM gene) is a common event in lymphoid malignancy. Frequent inactivating mutations of the ATM gene have been reported in patients with rare sporadic T cell prolymphocytic leukaemia (T-PLL), B cell chronic lymphocytic leukaemia (B-CLL), and most recently, mantle cell lymphoma (MCL). In contrast to the ATM mutation pattern in AT, the most frequent nucleotide changes in these sporadic lymphoid malignancies were missense mutations. The presence of inactivating mutations, together with the deletion of the normal copy of the ATM gene in some patients with T-PLL, B-CLL, and MCL, establishes somatic inactivation of the ATM gene in the pathogenesis of lymphoid malignancies, and strongly suggests that ATM functions as a tumour suppressor. The presence of missense mutations in the germline of patients with B-CLL has been reported, suggesting that some patients with B-CLL may be constitutional AT heterozygotes. The putative hereditary predisposition of B-CLL, although intriguing, warrants further investigation.
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Affiliation(s)
- J Boultwood
- Leukaemia Research Fund Molecular Haematology Unit, Nuffield Department of Clinical Laboratory Sciences, John Radcliffe Hospital, Headington, Oxford, OX3 9DU, UK.
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24
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Rivero-Carmena M, Porras O, Pelaez B, Pacheco-Castro A, Gatti RA, Regueiro JR. Membrane and transmembrane signaling in Herpesvirus saimiri-transformed human CD4(+) and CD8(+) T lymphocytes is ATM-independent. Int Immunol 2000; 12:927-35. [PMID: 10837420 DOI: 10.1093/intimm/12.6.927] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In the genetic disorder ataxia telangiectasia (AT), humoral (B) and cellular (T) immunological abnormalities are frequently observed. As a consequence, AT patients are predisposed to life-threatening sinopulmonary infections. The pathogenic mechanisms remain unknown, but a role for ATM in signal transduction from membrane receptors has been proposed. We have explored the effects of a defective ATMgene on isolated human T-lineage cells from 13 AT patients with proven T cell dysfunction by transforming their CD4(+) and CD8(+) T lymphocytes with Herpesvirus saimiri, and analyzing their signaling behavior as compared to normal controls. Several functional parameters were assayed in response to both membrane (anti-CD3 and IL-2) and transmembrane (phorbol myristate acetate plus the calcium ionophore ionomycin) stimuli: (i) calcium mobilization, (ii) induction of activation molecules (CD25, CD40 ligand, CD69 and CD71), (iii) cytokine synthesis (IL-2 and tumor necrosis factor-alpha) and (iv) proliferation. All these early and late activation events were found to be normal in the transformed ATM-/-T cells, indicating that ATM is not necessary for their induction. As expected, ATM-/- transformed T cells showed an increased radiosensitivity by both radioresistant DNA synthesis and cell survival assays. In contrast to an earlier report testing transformed B lymphocytes, our results indicate that transformed mature peripheral T lymphocytes from AT patients do not have intrinsic immune function defects. Rather, the described T-lineage signaling impairments observed in patients may be secondary in vivo to extrinsic ATM-dependent suppressive factors and/or to a developmental defect. These transformed T cells may help to understand the distinct biological role of ATM in different cell types and to develop rational therapies for the immunological dysfunction of AT patients.
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Affiliation(s)
- M Rivero-Carmena
- Inmunología, Facultad de Medicina, Universidad Complutense, 28040 Madrid, Spain
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25
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Becker-Catania SG, Chen G, Hwang MJ, Wang Z, Sun X, Sanal O, Bernatowska-Matuszkiewicz E, Chessa L, Lee EY, Gatti RA. Ataxia-telangiectasia: phenotype/genotype studies of ATM protein expression, mutations, and radiosensitivity. Mol Genet Metab 2000; 70:122-33. [PMID: 10873394 DOI: 10.1006/mgme.2000.2998] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Previous studies on a limited number of ataxia-telangiectasia (A-T) patients with detectable levels of intracellular ATM protein have suggested a genotype/phenotype correlation. We sought to elucidate this possible correlation by comparing ATM protein levels with mutation types, radiosensitivity, and clinical phenotype. In this study, Western blot analysis was used to measure ATM protein in lysates of lymphoblastoid cell lines (LCLs) from 123 unrelated A-T patients, 10 A-T heterozygotes, and 10 patients with phenotypes similar to A-T. Our Western blot protocol can detect the presence of ATM protein in as little as 1 microg of total protein; at least 25 microg of protein was tested for each individual. ATM protein was absent in 105 of the 123 patients (85%); most of these patients had truncating mutations. The remaining subset of 18 patients (15%) had reduced levels of normal-sized ATM protein; missense mutations were more common in this subset. We used a colony survival assay to characterize the phenotypic response of the LCLs to radiation exposure; patients with or without detectable ATM protein were typically radiosensitive. Nine of 10 A-T heterozygotes also had reduced expression of ATM, indicating that both alleles contribute to ATM protein production. These data suggest that although ATM-specific mRNA is abundant in A-T cells, the abnormal ATM protein is unstable and is quickly targeted for degradation. We found little correlation between level of ATM protein and the type of underlying mutation, the clinical phenotype, or the radiophenotype.
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Affiliation(s)
- S G Becker-Catania
- Department of Pathology and Laboratory Medicine, UCLA School of Medicine, Los Angeles, California, 90095, USA
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26
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Abstract
Deficiencies in the ability of cells to sense and repair damage in individuals with rare genetic instability syndromes increase the risk of developing cancer. Ataxia-telangiectasia (A-T), such a condition, is associated with a high incidence of leukemia and lymphoma that develop in childhood. Although A-T is an autosomal recessive disorder, some penetrance appears in individuals with one mutated ATM gene (A-T carriers), namely, an increased risk of developing breast cancer. The gene mutated in A-T, designated ATM, is homologous to several DNA damage recognition and cell cycle checkpoint control genes from other organisms. Recent studies suggest that ATM is activated primarily in response to double-strand breaks, the major cytotoxic lesion caused by ionizing radiation, and can directly bind to and phosphorylate c-Abl, p53, and replication protein A (RPA). Analysis of ATM mutations in patients with A-T or with sporadic non-A-T cancers has suggested the existence of two classes of ATM mutation: null mutations leading to A-T and dominant negative missense mutations predisposing to cancer in the heterozygous state. Studies with A-T mouse models have helped determine the basis of lymphoid tumorigenesis in A-T and have shown that ATM plays a critical role in maintaining genetic stability by ensuring high-fidelity execution of chromosomal events. Thus, ATM appears to act as a caretaker of the genome.
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Affiliation(s)
- K K Khanna
- The Queensland Institute of Medical Research, Brisbane, Australia.
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27
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Broeks A, Russell NS, Floore AN, Urbanus JH, Dahler EC, van T Veer MB, Hagenbeek A, Noordijk EM, Crommelin MA, van Leeuwen FE, van T Veer LJ. Increased risk of breast cancer following irradiation for Hodgkin's disease is not a result of ATM germline mutations. Int J Radiat Biol 2000; 76:693-8. [PMID: 10866292 DOI: 10.1080/095530000138367] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
PURPOSE Long-term survivors of Hodgkin's disease who received mantle-field irradiation at a young age have a strongly increased risk of developing breast cancer. The purpose of this study was to investigate whether this increased risk was substantially greater among women heterozygous for a germline mutation in the ataxia-telangiectasia gene (ATM). MATERIALS AND METHODS Thirty-two patients were selected who had developed breast cancer at least 10 years following irradiation for Hodgkin's disease before the age of 45 years. In these patients, the complete open reading frame of the ATM gene was analysed for the presence of germline mutations using the protein truncation test and two mutation-specific tests, followed by genomic sequencing. RESULTS No A-T disease causing germline mutations were found in these selected Hodgkin patients. However, several alternative splicing events were detected which might influence protein expression levels. CONCLUSIONS The data suggest that truncating mutations in the ATM gene are not a major component underlying the increased risk of breast cancer following Hodgkin's disease.
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Affiliation(s)
- A Broeks
- Department of Experimental Therapy, The Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, Amsterdam
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28
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29
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Regueiro JR, Porras O, Lavin M, Gatti RA. ATAXIA-TELANGIECTASIA. Radiol Clin North Am 2000. [DOI: 10.1016/s0033-8389(22)00186-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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30
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Gatti RA, Tward A, Concannon P. Cancer risk in ATM heterozygotes: a model of phenotypic and mechanistic differences between missense and truncating mutations. Mol Genet Metab 1999; 68:419-23. [PMID: 10607471 DOI: 10.1006/mgme.1999.2942] [Citation(s) in RCA: 153] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The failure to find an increased frequency of ATM mutations in large cancer cohorts, especially breast cancer, is contrary to what was anticipated based on the increased cancer susceptibility of obligate ATM heterozygotes from families with ataxia-telangiectasia (A-T). We hypothesize that this paradox might be resolved if two types of ATM heterozygotes exist and the phenotypes differ, i.e., those with truncating types of mutations (ATM(trunc)), that make no protein, and those with missense types of mutations (ATM(mis)), that make reduced amounts of defective protein. The phenotype of ATM(trunc/trunc) mutations is the A-T syndrome; the phenotype of ATM(mis/mis) mutations, judging from the few homozygous patients that have been documented, appears to include some neurological features and cancer susceptibility but not the A-T syndrome. Evidence is reviewed which suggests that ATM(mis/wt) mutations are technically more difficult to detect than ATM(trunc/wt) mutations. Despite this, most large cancer cohort studies have identified mainly missense mutations and few truncating mutations. This model would require a paradigm shift for cancer risk analyses, to recognize the existence of different allele frequencies for the two types of A-T heterozygotes.
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Affiliation(s)
- R A Gatti
- Department of Pathology, Los Angeles, California 90095, USA.
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31
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Bebb DG, Yu Z, Chen J, Telatar M, Gelmon K, Phillips N, Gatti RA, Glickman BW. Absence of mutations in the ATM gene in forty-seven cases of sporadic breast cancer. Br J Cancer 1999; 80:1979-81. [PMID: 10471049 PMCID: PMC2363154 DOI: 10.1038/sj.bjc.6690630] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Epidemiological evidence points to an increased risk of breast cancer in ataxia telangiectasia (AT) heterozygote women. Previous attempts to screen early onset or familial breast cancer patients failed to confirm an association. The issue of AT and late onset sporadic breast cancer remained unresolved. We screened 47 women who developed later onset, sporadic breast cancer for ataxia telangiectasia mutated (ATM) mutations. No mutations were found.
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Affiliation(s)
- D G Bebb
- Centre for Environmental Health, Department of Biology, University of Victoria, Canada
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32
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Castellví-Bel S, Sheikhavandi S, Telatar M, Tai LQ, Hwang M, Wang Z, Yang Z, Cheng R, Gatti RA. New mutations, polymorphisms, and rare variants in the ATM gene detected by a novel SSCP strategy. Hum Mutat 1999; 14:156-62. [PMID: 10425038 DOI: 10.1002/(sici)1098-1004(1999)14:2<156::aid-humu7>3.0.co;2-e] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The gene for ataxia-telangiectasia, ATM, spans about 150 kb of genomic DNA. ATM mutations are found along the entire gene, with no evidence of a mutational hot spot. Using DNA as the starting material, we screened the ATM gene in 92 A-T patients, using an optimized single-strand conformation polymorphism (SSCP) technique that detected all previously known mutations in the polymerase chain reaction (PCR) segments being analyzed. To expedite screening, we sequentially loaded the SSCP gels with three different sets of PCR products that were pretested to avoid overlapping patterns. Many of the DNA changes we detected were intragenic polymorphisms. Of an expected 177 unknown mutations, we detected approximately 70%, mostly protein truncating mutations (that would have been detectable by protein truncation testing if RNA starting material had been available). Mutations have now been defined for every exon of the ATM gene. Herein, we present 35 new mutations and 34 new intragenic polymorphisms or rare variants within the ATM gene. This is the most comprehensive compilation of ATM polymorphisms assembled to date. Defining polymorphic sites as well as mutations in the ATM gene will be of great importance in designing automated methods for detecting mutations.
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Affiliation(s)
- S Castellví-Bel
- Department of Pathology, School of Medicine, University of California at Los Angeles, Los Angeles, California 90095-1732, USA
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