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Rawat A, Tyagi R, Chaudhary H, Pandiarajan V, Jindal AK, Suri D, Gupta A, Sharma M, Arora K, Bal A, Madaan P, Saini L, Sahu JK, Ogura Y, Kato T, Imai K, Nonoyama S, Singh S. Unusual clinical manifestations and predominant stopgain ATM gene variants in a single centre cohort of ataxia telangiectasia from North India. Sci Rep 2022; 12:4036. [PMID: 35260754 PMCID: PMC8904522 DOI: 10.1038/s41598-022-08019-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 03/01/2022] [Indexed: 11/09/2022] Open
Abstract
Germline ATM gene variations result in phenotypic heterogeneity characterized by a variable degree of disease severity. We retrospectively collected clinical, genetic, and immunological data of 26 cases with A-T. Clinical manifestations included oculocutaneous telangiectasia (100%), ataxia (100%), fever, loose stools or infection (67%), cerebellar atrophy (50%), nystagmus (8%), dysarthria (15.38%), and visual impairment (8%). Genetic analysis confirmed ATM gene variations in 16 unrelated cases. The most common type of variation was stopgain variants (56%). Immunoglobulin profile indicated reduced IgA, IgG, and IgM in 94%, 50%, and 20% cases, respectively. T cell lymphopenia was observed in 80% of cases among those investigated. Unusual presentations included an EBV-associated smooth muscle tumour located in the liver in one case and Hyper IgM syndrome-like presentation in two cases. Increased immunosenescence was observed in T-cell subsets (CD4+CD57+ and CD8+CD57+). T-cell receptor excision circles (TRECs) were reduced in 3/8 (37.50%) cases.
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Affiliation(s)
- Amit Rawat
- Allergy and Immunology Laboratory, Department of Pediatrics, Advanced Pediatric Centre, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, 160012, India.
| | - Rahul Tyagi
- Allergy and Immunology Laboratory, Department of Pediatrics, Advanced Pediatric Centre, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, 160012, India
| | - Himanshi Chaudhary
- Allergy and Immunology Laboratory, Department of Pediatrics, Advanced Pediatric Centre, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, 160012, India
| | - Vignesh Pandiarajan
- Allergy and Immunology Laboratory, Department of Pediatrics, Advanced Pediatric Centre, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, 160012, India
| | - Ankur Kumar Jindal
- Allergy and Immunology Laboratory, Department of Pediatrics, Advanced Pediatric Centre, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, 160012, India
| | - Deepti Suri
- Allergy and Immunology Laboratory, Department of Pediatrics, Advanced Pediatric Centre, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, 160012, India
| | - Anju Gupta
- Allergy and Immunology Laboratory, Department of Pediatrics, Advanced Pediatric Centre, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, 160012, India
| | - Madhubala Sharma
- Allergy and Immunology Laboratory, Department of Pediatrics, Advanced Pediatric Centre, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, 160012, India
| | - Kanika Arora
- Allergy and Immunology Laboratory, Department of Pediatrics, Advanced Pediatric Centre, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, 160012, India
| | - Amanjit Bal
- Department of Histopathology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Priyanka Madaan
- Pediatric Neurology Unit, Department of Pediatrics, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Lokesh Saini
- Pediatric Neurology Unit, Department of Pediatrics, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Jitendra Kumar Sahu
- Pediatric Neurology Unit, Department of Pediatrics, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Yumi Ogura
- National Defense Medical College (Japan), Saitama, Japan
| | - Tamaki Kato
- National Defense Medical College (Japan), Saitama, Japan
| | - Kohsuke Imai
- National Defense Medical College (Japan), Saitama, Japan.,Tokyo Medical and Dental University, Tokyo, Japan
| | | | - Surjit Singh
- Allergy and Immunology Laboratory, Department of Pediatrics, Advanced Pediatric Centre, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, 160012, India
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2
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Al-Muhaizea MA, Aldeeb H, Almass R, Jaber H, Binhumaid F, Alquait L, Abukhalid M, Aldhalaan H, Alsagob M, Al-Bakheet A, Aldosary M, Alkofide H, Alrasheed MM, Colak D, Kaya N. Genetics of ataxia telangiectasia in a highly consanguineous population. Ann Hum Genet 2021; 86:34-44. [PMID: 34582042 DOI: 10.1111/ahg.12445] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 08/31/2021] [Accepted: 09/03/2021] [Indexed: 12/17/2022]
Abstract
Ataxia telangiectasia (AT) is a rare autosomal recessive multisystemic disorder. It usually presents in toddler years with progressive ataxia and oculomotor apraxia, or less commonly, in the late-first or early-second decade of life with mixed movement disorders. Biallelic mutations in ataxia telangiectasia mutated gene (ATM) cause AT phenotype, a disease not well documented in Saudi Arabia, a highly consanguineous society. We studied several Saudi AT patients, identified ATM variants, and investigated associated clinical features. We included 17 patients from 12 consanguineous families. All patients had comprehensive clinical and radiological assessment, and most were examined through whole-exome sequencing (WES). Selected individuals were analyzed using various genetic approaches. We identified five different ATM variants in our patients: three previously reported mutations, and two novel variants. Nearly all patients had classical AT presentation except for two patients with a milder phenotype. Among the three known variants, a deletion causing truncation (c.381delA resulting in p.(Val128Ter)) was identified in 13 patients. Two patients harboured the other two truncating variants, (c.9001_9002delAG resulting in p.Ser3001Phefs*6) and (c.9066delA resulting in p.Glu3023Alafs*10) and two patients had novel compound heterozygous variants (NM_000051.3:Paternal Allele:c.8762C > G;p.Thr2921Arg and Maternal Allele:c.1057T > C;p.Cys353Arg). We speculate that c.381delA is a founder mutation in our population. This study provides a genotype-phenotype relationship in a previously unstudied consanguineous population. Our findings contribute to improve local clinical care, therapy, and genetic counseling.
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Affiliation(s)
- Mohammed A Al-Muhaizea
- Department of Neurosciences, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia
| | - Hanouf Aldeeb
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia.,Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia.,College of Pharmacy, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Rawan Almass
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia.,Department of Medical Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia
| | - Hadeel Jaber
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia.,College of Pharmacy, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Felwa Binhumaid
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia
| | - Laila Alquait
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia.,Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia
| | - Musaad Abukhalid
- Department of Neurosciences, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia
| | - Hesham Aldhalaan
- Department of Neurosciences, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia
| | - Maysoon Alsagob
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia.,King Abdulaziz City for Science and Technology, Riyadh, Kingdom of Saudi Arabia
| | - Albandary Al-Bakheet
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia.,Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia
| | - Mazhor Aldosary
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia.,Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia
| | - Hadeel Alkofide
- College of Pharmacy, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Maha M Alrasheed
- College of Pharmacy, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Dilek Colak
- Department of Biostatistics, Epidemiology and Scientific Computing, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia
| | - Namik Kaya
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia.,Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia
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Pourahmadiyan A, Alipour P, Golchin N, Tabatabaiefar MA. Next-generation sequencing reveals a novel pathogenic variant in the ATM gene. Int J Neurosci 2021; 132:558-562. [PMID: 32962506 DOI: 10.1080/00207454.2020.1826944] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
INTRODUCTION Ataxia telangiectasia (A-T) is a rare autosomal recessive, multisystemic disease. Patients with the A-T syndrome present a broad spectrum of disease phenotypes. The ATM (ataxia telangiectasia mutated) gene, the only causative gene for A-T. METHOD A patient of Persian origin presenting with typical A-T was referred to our genetics centre for specialized genetic counselling and testing. Targeted next-generation sequencing (NGS) was applied. Sanger sequencing was used to confirm the candidate variant. Modelling was performed using the SWISS-MODEL server. RESULTS A homozygous stop-gain variant c.829G > T (p.E277*) was found in the ATM gene. This variant was confirmed by Sanger sequencing and modelling of native structure, and truncated structure was performed. CONCLUSION To date, very few pathogenic variants of the ATM gene have been reported from the Iranian population. The finding has implications in molecular diagnostic for A-T in Iran.
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Affiliation(s)
- Azam Pourahmadiyan
- Cellular and Molecular Research Center, Basic Health Sciences Institute, Shahrekord University of Medical Sciences, Shahrekord, Iran
| | - Paria Alipour
- Cellular and Molecular Research Center, Basic Health Sciences Institute, Shahrekord University of Medical Sciences, Shahrekord, Iran
| | - Neda Golchin
- Ahvaz Noor Medical Genetics Laboratory, Ahvaz, Iran
| | - Mohammad Amin Tabatabaiefar
- Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.,Pediatric Inherited Diseases Research Center, Research Institute for Primordial Prevention of Non-communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran
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4
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Suspitsin E, Sokolenko A, Bizin I, Tumakova A, Guseva M, Sokolova N, Vakhlyarskaya S, Kondratenko I, Imyanitov E. ATM mutation spectrum in Russian children with ataxia-telangiectasia. Eur J Med Genet 2019; 63:103630. [PMID: 30772474 DOI: 10.1016/j.ejmg.2019.02.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2018] [Revised: 01/11/2019] [Accepted: 02/10/2019] [Indexed: 11/25/2022]
Abstract
Ataxia-telangiectasia (AT) is a severe autosomal recessive orphan disease characterized by a number of peculiar clinical manifestations. Genetic diagnosis of AT is complicated due to a large size of the causative gene, ATM. We used next-generation sequencing (NGS) technology for the ATM analysis in 17 children with the clinical diagnosis of AT. Biallelic mutations in the ATM gene were identified in all studied subjects; these lesions included one large gene rearrangement, which was reliably detected by NGS and validated by multiplex ligation-dependent probe amplification (MLPA). There was a pronounced founder effect, as 17 of 30 (57%) pathogenic ATM alleles in the patients of Slavic origin were represented by three recurrent mutations (c.5932G > T, c.450_453delTTCT, and c.1564_1565delGA). These data have to be taken into account while considering the genetic diagnosis and screening for ataxia-telangiectasia syndrome.
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Affiliation(s)
- Evgeny Suspitsin
- St.-Petersburg Pediatric Medical University, St.-Petersburg, Russia; N.N. Petrov Institute of Oncology, St.-Petersburg, Russia.
| | - Anna Sokolenko
- St.-Petersburg Pediatric Medical University, St.-Petersburg, Russia; N.N. Petrov Institute of Oncology, St.-Petersburg, Russia
| | - Ilya Bizin
- N.N. Petrov Institute of Oncology, St.-Petersburg, Russia
| | | | - Marina Guseva
- St.-Petersburg Pediatric Medical University, St.-Petersburg, Russia
| | | | - Svetlana Vakhlyarskaya
- Russian Children Clinical Hospital, N.N. Pirogov National Research Medical University, Moscow, Russia
| | - Irina Kondratenko
- Russian Children Clinical Hospital, N.N. Pirogov National Research Medical University, Moscow, Russia
| | - Evgeny Imyanitov
- St.-Petersburg Pediatric Medical University, St.-Petersburg, Russia; N.N. Petrov Institute of Oncology, St.-Petersburg, Russia; I.I. Mechnikov North-Western Medical University, St.-Petersburg, Russia; St.-Petersburg State University, St.-Petersburg, Russia
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5
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Tabatabaiefar MA, Alipour P, Pourahmadiyan A, Fattahi N, Shariati L, Golchin N, Mohammadi-Asl J. A novel pathogenic variant in an Iranian Ataxia telangiectasia family revealed by next-generation sequencing followed by in silico analysis. J Neurol Sci 2017; 379:212-216. [PMID: 28716242 DOI: 10.1016/j.jns.2017.06.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2016] [Revised: 06/04/2017] [Accepted: 06/11/2017] [Indexed: 01/27/2023]
Abstract
Ataxia telangiectasia (A-T) is a neurodegenerative autosomal recessive disorder with the main characteristics of progressive cerebellar degeneration, sensitivity to ionizing radiation, immunodeficiency, telangiectasia, premature aging, recurrent sinopulmonary infections, and increased risk of malignancy, especially of lymphoid origin. Ataxia Telangiectasia Mutated gene, ATM, as a causative gene for the A-T disorder, encodes the ATM protein, which plays an important role in the activation of cell-cycle checkpoints and initiation of DNA repair in response to DNA damage. Targeted next-generation sequencing (NGS) was performed on an Iranian 5-year-old boy presented with truncal and limb ataxia, telangiectasia of the eye, Hodgkin lymphoma, hyper pigmentation, total alopecia, hepatomegaly, and dysarthria. Sanger sequencing was used to confirm the candidate pathogenic variants. Computational docking was done using the HEX software to examine how this change affects the interactions of ATM with the upstream and downstream proteins. Three different variants were identified comprising two homozygous SNPs and one novel homozygous frameshift variant (c.80468047delTA, p.Thr2682ThrfsX5), which creates a stop codon in exon 57 leaving the protein truncated at its C-terminal portion. Therefore, the activation and phosphorylation of target proteins are lost. Moreover, the HEX software confirmed that the mutated protein lost its interaction with upstream and downstream proteins. The variant was classified as pathogenic based on the American College of Medical Genetics and Genomics guideline. This study expands the spectrum of ATM pathogenic variants in Iran and demonstrates the utility of targeted NGS in genetic diagnostics.
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Affiliation(s)
- Mohammad Amin Tabatabaiefar
- Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran; Pediatric Inherited Diseases Research Center, Research Institute for Primordial Prevention of Non-communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Paria Alipour
- Cellular and Molecular Research Center, Basic Health Sciences Institute, Shahrekord University of Medical Sciences, Shahrekord, Iran
| | - Azam Pourahmadiyan
- Cellular and Molecular Research Center, Basic Health Sciences Institute, Shahrekord University of Medical Sciences, Shahrekord, Iran
| | - Najmeh Fattahi
- Clinical Biochemistry Research Center, Basic Health Sciences Institute, Shahrekord University of Medical Science, Shahrekord, Iran
| | - Laleh Shariati
- Cardiovascular Research Center, Cardiovascular Research Institute, Isfahan University of Medical Sciences, Isfahan, Iran
| | | | - Javad Mohammadi-Asl
- Ahvaz Noor Genetics Laboratory, Ahvaz, Iran; Department of Medical Genetics, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
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6
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Podralska MJ, Stembalska A, Ślęzak R, Lewandowicz-Uszyńska A, Pietrucha B, Kołtan S, Wigowska-Sowińska J, Pilch J, Mosor M, Ziółkowska-Suchanek I, Dzikiewicz-Krawczyk A, Słomski R. Ten new ATM alterations in Polish patients with ataxia-telangiectasia. Mol Genet Genomic Med 2014; 2:504-11. [PMID: 25614872 PMCID: PMC4303220 DOI: 10.1002/mgg3.98] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 06/20/2014] [Accepted: 06/25/2014] [Indexed: 11/23/2022] Open
Abstract
Inherited biallelic mutations of the ATM gene are responsible for the
development of ataxia telangiectasia (AT). The objective of the present study was to conduct
molecular analysis of the ATM gene in a cohort of 24 Polish patients with
ataxia-telangiectasia with aim being to provide an updated mutational spectrum in Polish AT
patients. As a result of molecular analysis, the status of recurrent mutation was confirmed and ten
new ATM variants were detected. Application of MLPA analysis allowed the detection of large genomic
deletion. Previously, this type of mutation had never been seen in our population. Finally, in
silico analysis was carried out for newly detected ATM alterations. In addition, functional analysis
was performed to evaluate the effects of intronic variants:
c.3402+30_3402+32delATC.
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Affiliation(s)
| | | | - Ryszard Ślęzak
- Department of Genetics, Wroclaw Medical University Wroclaw, Poland
| | - Aleksandra Lewandowicz-Uszyńska
- 3rd Department and Clinic of Paediatrics, Immunology and Rheumatology of Developmental Age, Wroclaw Medical University Wroclaw, Poland
| | - Barbara Pietrucha
- Department of Immunology, The Children's Memorial Health Institute Warsaw, Poland
| | - Sylwia Kołtan
- Department of Pediatrics, Hematology and Oncology, Institute of Pediatrics, Medical Academy Bydgoszcz, Poland
| | | | - Jacek Pilch
- Department of Child Neurology, Medical University of Silesia Katowice, Poland
| | - Maria Mosor
- Institute of Human Genetics of the Polish Academy of Sciences Poznań, Poland
| | | | | | - Ryszard Słomski
- Institute of Human Genetics of the Polish Academy of Sciences Poznań, Poland
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7
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Latif AH, Tabassomi F, Abolhassani H, Hammarström L. Molecular diagnosis of primary immunodeficiency diseases in a developing country: Iran as an example. Expert Rev Clin Immunol 2014; 10:385-96. [DOI: 10.1586/1744666x.2014.880654] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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8
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Against Lung Cancer Cells: To Be, or Not to Be, That Is the Problem. LUNG CANCER INTERNATIONAL 2012; 2012:659365. [PMID: 26316936 PMCID: PMC4437407 DOI: 10.1155/2012/659365] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/22/2011] [Accepted: 01/04/2012] [Indexed: 11/18/2022]
Abstract
Tobacco smoke and radioactive radon gas impose a high risk for lung cancer. The radon-derived ionizing radiation and some components of cigarette smoke induce oxidative stress by generating reactive oxygen species (ROS). Respiratory lung cells are subject to the ROS that causes DNA breaks, which subsequently bring about DNA mutagenesis and are intimately linked with carcinogenesis. The damaged cells by oxidative stress are often destroyed through the active apoptotic pathway. However, the ROS also perform critical signaling functions in stress responses, cell survival, and cell proliferation. Some molecules enhance radiation-induced tumor cell killing via the reduction in DNA repair levels. Hence the DNA repair levels may be a novel therapeutic modality in overcoming drug resistance in lung cancer. Either survival or apoptosis, which is determined by the balance between DNA damage and DNA repair levels, may lender the major problems in cancer therapy. The purpose of this paper is to take a closer look at risk factor and at therapy modulation factor in lung cancer relevant to the ROS.
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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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Chessa L, Piane M, Magliozzi M, Torrente I, Savio C, Lulli P, De Luca A, Dallapiccola B. Founder effects for ATM gene mutations in Italian Ataxia Telangiectasia families. Ann Hum Genet 2009; 73:532-9. [PMID: 19691550 DOI: 10.1111/j.1469-1809.2009.00535.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We screened ATM gene mutations in 104 Italian Ataxia-Telangiectasia patients from 91 unrelated families (detection rate 90%) and found 21 recurrent mutations in 63 families. The majority (67%) of patients were compound heterozygotes, while 33% were homozygotes. To determine the existence of common haplotypes and potential founder effects, we analyzed five microsatellite markers within and flanking the ATM gene. Haplotype analysis was carried out in 48/63 families harbouring 16 of the 21 recurrent mutations. Forty different haplotypes were detected in the 48 A-T families studied. We found that the majority of patients with the same recurrent mutation originated from the same geographical area. All but one recurrent mutation analyzed displayed a common haplotype suggesting a single origin that then spread to different geographical areas. The high number of different haplotypes does not allow the screening of ATM mutations by haplotype analysis alone in the Italian population. The finding of recurrent public mutations without founder effect suggests the existence of 'mild' hot spots of mutation located along the sequence of the ATM gene.
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Affiliation(s)
- Luciana Chessa
- II School of Medicine, University La Sapienza, I-00189 Roma, Italy.
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11
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Isaian A, Bogdanova NV, Houshmand M, Movahadi M, Agamohammadi A, Rezaei N, Atarod L, Sadeghi-Shabestari M, Tonekaboni SH, Chavoshzadeh Z, Hassani SMS, Mirfakhrai R, Cheraghi T, Kalantari N, Ataei M, Dork-Bousset T, Sanati MH. BAK, BAX, and NBK/BIK Proapoptotic Gene Alterations in Iranian Patients with Ataxia Telangiectasia. J Clin Immunol 2009; 30:132-7. [DOI: 10.1007/s10875-009-9340-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2009] [Accepted: 09/29/2009] [Indexed: 11/28/2022]
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12
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Mitui M, Nahas SA, Du LT, Yang Z, Lai CH, Nakamura K, Arroyo S, Scott S, Purayidom A, Concannon P, Lavin M, Gatti RA. Functional and computational assessment of missense variants in the ataxia-telangiectasia mutated (ATM) gene: mutations with increased cancer risk. Hum Mutat 2009; 30:12-21. [PMID: 18634022 DOI: 10.1002/humu.20805] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The functional consequences of missense variants are often difficult to predict. This becomes especially relevant when DNA sequence changes are used to determine a diagnosis or prognosis. To analyze the consequences of 12 missense variants in patients with mild forms of ataxia-telangiectasia (A-T), we employed site-directed mutagenesis of ataxia-telangiectasia mutated (ATM) cDNA followed by stable transfections into a single A-T cell line to isolate the effects of each allele on the cellular phenotype. After induction of the transfected cells with CdCl2, we monitored for successful ATM transcription and subsequently assessed: 1) intracellular ATM protein levels; 2) ionizing radiation (IR)-induced ATM kinase activity; and 3) cellular radiosensitivity. We then calculated SIFT and PolyPhen scores for the missense changes. Nine variants produced little or no correction of the A-T cellular phenotype and were interpreted to be ATM mutations; SIFT/PolyPhen scores supported this. Three variants corrected the cellular phenotype, suggesting that they represented benign variants or polymorphisms. SIFT and PolyPhen scores supported the functional analyses for one of these variants (c.1709T>C); the other two were predicted to be "not tolerated" (c.6188G>A and c.6325T>G) and were classified as "operationally neutral." Genotype/phenotype relationships were compared: three deleterious missense variants were associated with an increased risk of cancer (c.6679C>T, c.7271T>G, and c.8494C>T). In situ mutagenesis represents an effective experimental approach for distinguishing deleterious missense mutations from benign or operationally neutral missense variants.
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Affiliation(s)
- M Mitui
- Department of Pathology and Laboratory Medicine, The David Geffen School of Medicine at the University of California, Los Angeles (UCLA), Los Angeles, California 90095-1732, USA
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13
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Bayat B, Houshmand M, Sanati MH, Moin M, Panahi MSS, Aleyasin SA, Isaian A, Farhoodi A. Use of D11S2179 and D11S1343 as markers for prenatal diagnosis of ataxia telangiectasia in Iranian patients. Arch Med Res 2007; 38:803-5. [PMID: 17845903 DOI: 10.1016/j.arcmed.2007.04.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2006] [Accepted: 04/24/2007] [Indexed: 10/23/2022]
Abstract
Ataxia telangiectasia (AT) is an autosomal recessive disorder with an estimated prevalence of 1/40,000 to 1/100,000 in reported populations. There is a 25% possibility for having an affected child when parents are carriers for the ATM gene mutation. There is no cure available for this disease and prenatal testing is strongly recommended for prevention of this disease. Although the preferred method is the direct mutation analysis of the ATM gene, the large size of the ATM gene with 63 exons and the large number of possible mutations in patients considerably limit efficiency of mutation analysis as a diagnostic choice. Indirect method is a better tool when parents are not carriers of founder mutation and pass different mutations to their children. Indirect molecular diagnosis using ATM-related molecular markers facilitates prenatal diagnosis of AT children. In this study, four molecular markers: D11S2179, D11S1787, D11S535, D11S1343 are genotyped in 19 unrelated families from different regions of Iran. Those markers are amplified using extracted sequence primers from the Gene Bank with their described PCR conditions. Amplified products were separated using denaturing PAGE gels, and data were analyzed to detect their pattern of inheritance in each family. In all families, segregation of alleles was according to Mendelian inheritance, and affected chromosomes were distinguishable from unaffected ones. All carriers and affected patients were diagnosed accurately. Thus, this method is effectively useful in prenatal diagnosis of AT.
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Affiliation(s)
- Behnaz Bayat
- Department of Medical Genetics, National Institute of Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran
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German J, Sanz MM, Ciocci S, Ye TZ, Ellis NA. Syndrome-causing mutations of the BLM gene in persons in the Bloom's Syndrome Registry. Hum Mutat 2007; 28:743-53. [PMID: 17407155 DOI: 10.1002/humu.20501] [Citation(s) in RCA: 135] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Bloom syndrome (BS) is caused by homozygous or compound heterozygous mutations in the RecQ DNA helicase gene BLM. Since the molecular isolation of BLM, characterization of BS-causing mutations has been carried out systematically using samples stored in the Bloom's Syndrome Registry. In a survey of 134 persons with BS from the Registry, 64 different mutations were identified in 125 of them, 54 that cause premature protein-translation termination and 10 missense mutations. In 102 of the 125 persons in whom at least one BLM mutation was identified, the mutation was recurrent, that is, it was shared by two or more persons with BS; 19 of the 64 different mutations were recurrent. Ethnic affiliations of the persons who carry recurrent mutations indicate that the majority of such persons inherit their BLM mutation identical-by-descent from a recent common ancestor, a founder. The presence of widespread founder mutations in persons with BS points to population genetic processes that repeatedly and pervasively generate mutations that recur in unrelated persons.
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Affiliation(s)
- James German
- Weill Medical College of Cornell University, New York, New York, USA
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