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Li Y, Ye J, Liang L, Tan X, Zheng L, Qin T, Yu L. Detection of α-thalassemia South-East Asian deletion based on a fully integrated digital polymerase chain reaction system DropXpert S6. Hematology 2024; 29:2365596. [PMID: 38864494 DOI: 10.1080/16078454.2024.2365596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Accepted: 06/04/2024] [Indexed: 06/13/2024] Open
Abstract
OBJECTIVES This study aimed to establish a droplet digital polymerase chain reaction (ddPCR) assay for South-East Asian (SEA) deletion based on a fully integrated digital PCR system DropXpert S6. METHODS A total of 151 whole blood samples, 10 chorionic villus samples, and 17 amniotic fluid samples were collected, including 106 SEA heterozygotes, 43 normal individuals, 10 Hb Bart's hydrops details, and 19 SEA deletions combined with other genotypes.Genotypes of these samples were determined by the Gap-PCR method. We perform a series of optimizations of the ddPCR system to ensure the performance of the entire ddPCR reaction, such as droplet stability, fluorescence clustering, sensitivity, and accuracy. RESULTS Our assay exhibited 99.4% (177/178) accuracy compared with the Gap-PCR method, and the minimum detection limit of DNA was 0.1 ng/μL.Both targets have reliable linearity, R2 = 0.9999 for the α-thalassemia SEA deletion allele and R2 = 1 for the wild-type allele. The coefficient of variation for α-thalassemia SEA deletion allele detection at 2 and 10 ng/μL concentrations was 5.42% and 1.91%, respectively. In contrast, the coefficient of variation for wild-type allele detection was 4.06% and 1.83%, demonstrating its high quantitative accuracy. In addition, the DropXpert S6 PCR system showed some advantages over other ddPCR instruments, such as reducing testing costs, simplifying and automating the workflow. CONCLUSIONS The DropXpert S6 PCR system provided a highly accurate diagnosis for α-thalassemia SEA deletion and can be used to detect α-thalassemia as an alternative method.
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Affiliation(s)
- Youqiong Li
- Center for Medical Genetics and Prenatal Diagnosis, People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, People's Republic of China
| | - Junwei Ye
- Research and Development Department, Shenzhen Biorain Technology Co., Ltd, Shenzhen, People's Republic of China
| | - Liang Liang
- Center for Medical Genetics and Prenatal Diagnosis, People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, People's Republic of China
| | - Xiao Tan
- Research and Development Department, Shenzhen Biorain Technology Co., Ltd, Shenzhen, People's Republic of China
| | - Lihong Zheng
- Center for Medical Genetics and Prenatal Diagnosis, People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, People's Republic of China
| | - Ting Qin
- Center for Medical Genetics and Prenatal Diagnosis, People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, People's Republic of China
| | - Linfen Yu
- Research and Development Department, Shenzhen Biorain Technology Co., Ltd, Shenzhen, People's Republic of China
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Wei X, Wang X, Xiong F, Zhang X, Liu D, Zhou W, He F, Shang X. SNPscan Combined With CNVplex as a High-Performance Diagnostic Method for Thalassemia. Prenat Diagn 2024. [PMID: 39256948 DOI: 10.1002/pd.6661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 06/20/2024] [Accepted: 08/25/2024] [Indexed: 09/12/2024]
Abstract
OBJECTIVE Thalassemia is a Mendelian-inherited blood disorder with severe consequences, including disability and mortality, making it a significant public health concern. Therefore, there is an urgent need for precise diagnostic technologies. We introduce two innovative diagnostic techniques for thalassemia, SNPscan and CNVplex, designed to enhance molecular diagnostics of thalassemia. METHODS The SNPscan and CNVplex assays utilize variations in PCR product length and fluorescence to identify multiple mutations. In the SNPscan method, we designed three probes per locus: two 5' and one 3', and incorporated allele identification link sequences into one of the 5' probes to distinguish the alleles. The detection system was designed for 67 previously reported loci in the Chinese population for a specific genetic condition. CNVplex identifies deletion types by analyzing the specific positions of probes within the globin gene. This innovative approach enables the detection of six distinct deletional mutations, enhancing the precision of thalassemia diagnostics. We evaluated and refined the methodologies in a training cohort of 100 individuals with confirmed HBA and HBB genotypes. The validation cohort, consisting of 1647 thalassemia patients and 100 healthy controls, underwent a double-blind study. Traditional diagnostic techniques served as the control methods. RESULTS In the training set of 100 samples, 10 mutations (Hb QS, Hb CS, Hb Westmead, CD17, CD26, CD41-42, IVS-II-654, --SEA, -α3.7 and -α4.2) were identified, consistent with those identified by traditional methods. The validation study showed that SNPscan/CNVplex offered superior molecular diagnostic capabilities for thalassemia, with 100% accuracy compared to 99.43% for traditional methods. Notably, the assay identified three previously undetected mutations in 10 cases, including two deletion mutations (Chinese Gγ(Aγδβ)0 del and SEA-HPFH), and one non-deletion mutation (Hb Q-Thailand). CONCLUSIONS The SNPscan/CNVplex assay is a cost-effective and user-friendly tool for diagnosing thalassemia, demonstrating high accuracy and reliability, and showing great potential as a primary diagnostic method in clinical practice.
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Affiliation(s)
- Xiaofeng Wei
- Department of Medical Genetics, School of Basic Medicine Science, Southern Medical University, Guangdong, China
- Experimental Education and Administration Center, School of Basic Medical Science, Southern Medical University, Guangdong, China
| | - Xingmin Wang
- Department of Medical Genetics, School of Basic Medicine Science, Southern Medical University, Guangdong, China
| | - Fu Xiong
- Department of Medical Genetics, School of Basic Medicine Science, Southern Medical University, Guangdong, China
- Experimental Education and Administration Center, School of Basic Medical Science, Southern Medical University, Guangdong, China
| | - Xinhua Zhang
- Department of Hematology, 923rd Hospital of the People's Liberation Army, Guangxi, China
| | - Dun Liu
- Reproductive Medical Center, Guangdong Women and Children Hospital, Guangdong, China
| | - Wanjun Zhou
- Department of Medical Genetics, School of Basic Medicine Science, Southern Medical University, Guangdong, China
- Experimental Education and Administration Center, School of Basic Medical Science, Southern Medical University, Guangdong, China
| | - Fei He
- Department of Medical Genetics, School of Basic Medicine Science, Southern Medical University, Guangdong, China
- Experimental Education and Administration Center, School of Basic Medical Science, Southern Medical University, Guangdong, China
| | - Xuan Shang
- Department of Medical Genetics, School of Basic Medicine Science, Southern Medical University, Guangdong, China
- Experimental Education and Administration Center, School of Basic Medical Science, Southern Medical University, Guangdong, China
- Innovation Center for Diagnostics and Treatment of Thalassemia, Nanfang Hospital, Southern Medical University, Guangdong, China
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Long J, Yu C, Sun L, Peng M, Song C, Mao A, Zhan J, Liu E. Comprehensive analysis of thalassemia alleles (CATSA) based on third-generation sequencing is a comprehensive and accurate approach for neonatal thalassemia screening. Clin Chim Acta 2024; 560:119749. [PMID: 38796052 DOI: 10.1016/j.cca.2024.119749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 01/06/2024] [Accepted: 05/22/2024] [Indexed: 05/28/2024]
Abstract
Thalassemia is one of the most common and damaging monogenic diseases in the world. It is caused by pathogenic variants of α- and/or β-globin genes, which disrupt the balance of these two protein chains and leads to α-thalassemia or β-thalassemia, respectively. Patients with α-thalassemia or β-thalassemia could exhibit a severe phenotype, with no simple and effective treatment. A three-tiered strategy of carrier screening, prenatal diagnosis and newborn screening has been established in China for the prevention and control of thalassemia, of which the first two parts have been studied thoroughly. The implementation of neonatal thalassemia screening is lagging, and the effectiveness of various screening programs has not yet been demonstrated. In this study, hemoglobin capillary electrophoresis (CE), hotspot testing method, and third-generation sequencing (TGS) were used in the variant detection of 2000 newborn samples, to assess the efficacy of these methods in neonatal thalassemia screening. Compared with CE (249, 12.45 %) and hotspot analysis (424, 21.2 %), CATSA detected the largest number of thalassemia variants (535, 26.75 %), which included 24 hotspot variants, increased copy number of α-globin gene, rare pathogenic variants, and three unreported potentially disease-causing variants. More importantly, CATSA directly determined the cis-trans relationship of variants in three newborns, which greatly shortens the clinical diagnosis time of thalassemia. CATSA showed a great advantage over other genetic tests and could become the most powerful technical support for the three-tiered prevention and control strategy of thalassemia.
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Affiliation(s)
- Ju Long
- School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, China; Laboratory of Medical Genetics, Qinzhou Maternal and Child Health Care Hospital, Qinzhou, Guangxi 535099, China.
| | - Chunhui Yu
- Laboratory of Medical Genetics, Qinzhou Maternal and Child Health Care Hospital, Qinzhou, Guangxi 535099, China
| | - Lei Sun
- School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, China; Laboratory of Medical Genetics, Qinzhou Maternal and Child Health Care Hospital, Qinzhou, Guangxi 535099, China
| | - Mingkui Peng
- Laboratory of Medical Genetics, Qinzhou Maternal and Child Health Care Hospital, Qinzhou, Guangxi 535099, China
| | - Chuanlu Song
- Laboratory of Medical Genetics, Qinzhou Maternal and Child Health Care Hospital, Qinzhou, Guangxi 535099, China
| | - Aiping Mao
- Third-Generation Sequencing BU, Berry Genomics Corporation, Beijing 102200, China
| | - Jiahan Zhan
- Third-Generation Sequencing BU, Berry Genomics Corporation, Beijing 102200, China
| | - Enqi Liu
- School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, China.
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Almomani AA, Shraim AS, Atoom AM, Abdel MBA, Alhmoud JF. Evaluation of the validity of the pre-marriage mean corpuscular volume value as a predictive test for b-thalassemia carrier status. J Med Biochem 2023; 42:195-205. [PMID: 36987417 PMCID: PMC10040200 DOI: 10.5937/jomb0-37682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 07/30/2022] [Indexed: 11/02/2022] Open
Abstract
Background The national mandatory premarital screening test is based on mean corpuscular volume (MCV) > 80 fL value for the detection of β-thalassemia to provide acceptance for marriage. The objective of this study is to assess the efficacy of MCV as a screening test for β-thalassemia trait in the present population. Methods This study was conducted on 418 blood samples collected from adult individuals. The diagnosis of β-thalassemia carrier was given to those having HbA2 values equal to or above 3.5%. The diagnostic reliability of different RBC indices and formulas in discriminating cases of β-thalassemia trait were evaluated. Finally, a new index called "Momani" was determined based on MCV, RDW and RBC count. Results β-thalassemia trait was identified in 10% of the cases. The measured MCV value was significantly lower in β-thalassemia carrier group compared to non-carrier group (p = <0.001). MCV value and RBC count showed a higher diagnostic reliability than other RBC indices. We found that MCV ≤ 74.45 fL is more suitable cutoff value of MCV with 86.2% specificity, 71.4% sensitivity, 36.6% positive predictive value, and 96.4% negative predictive value. Finally, our index "Momani" was found to be useful in predicting carrier and paralleled the performance of Sirdah, Mentzer, and Ehsani indices. Conclusions MCV<80 is a useful but not a perfect cutoff point for the screening of β-thalassemia carriers from noncarriers. The diagnostic accuracy of MCV can be improved by selecting a new cutoff value. Moreover, "Momani" index shows good discrimination ability in diagnosing β-thalassemia carrier in our population.
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Affiliation(s)
- Ali A. Almomani
- Al-Ahliyya Amman University, Pharmacological and Diagnostic Research Centre, Amman, Jordan
| | - Ala'a S. Shraim
- Al-Ahliyya Amman University, Faculty of Allied Medical Sciences, Department of Medical Laboratory Sciences, Amman, Jordan
| | - Ali M. Atoom
- Al-Ahliyya Amman University, Pharmacological and Diagnostic Research Centre, Amman, Jordan
| | - Majeed Bayan A. Abdel
- Al-Ahliyya Amman University, Pharmacological and Diagnostic Research Centre, Amman, Jordan
| | - Jehad F. Alhmoud
- Al-Ahliyya Amman University, Pharmacological and Diagnostic Research Centre, Amman, Jordan
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Wei B, Zhou W, Peng M, Long J, Wen W. The population incidence of thalassemia gene variants in Baise, Guangxi, P. R. China, based on random samples. Hematology 2022; 27:1026-1031. [PMID: 36066284 DOI: 10.1080/16078454.2022.2119736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023] Open
Abstract
OBJECTIVE Thalassemia is a monogenic genetic disorder with a high prevalence in populations in the southern region of China. The thalassemia gene prevalence rate in the Baise population in China is high, and several rare gene variants have been detected in the population of this region during routine testing by our study group. To accurately reveal the thalassemia gene variants carried by the population in Baise, and to provide a basis for the formulation of thalassemia prevention and control policies in the region, we conducted a more comprehensive study in a randomly selected population. RESULTS In all, 4,800 randomized individuals were recruited for testing from Baise, and the detection of hot spot thalassemia genetic variants were performed by Gap-PCR and PCR-RDB methods, combined with the relative quantification of homologous fragments and AS-PCR to expand the detection range. The prevalence of thalassemia variants in this population was 24.19%, among which 16.69% of individuals carried α-thalassemia gene variants alone, 5.62% carried β-thalassemia gene variants alone, and 1.88% carried both variants. CONCLUSIONS The use of positive primary screening combined with hot spot gene variant detection alone can result in a certain degree of missed detection. In the prevention and control of thalassemia in the region, testing institutions need to pay attention to the detection of rare thalassemia gene variants such as αααanti4.2, αααanti3.7, -α2.4, -α21.9, β-50, β-90, and βIVS-II-5, to provide more accurate genetic counseling advice to subjects.
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Affiliation(s)
- Bixiao Wei
- Clinical Laboratory, The Affiliated Shunde Hospital of Jinan University, Foshan, Guangdong, PR People's Republic of China
- Clinical Laboratory Center, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, PR People's Republic of China
- Clinical Laboratory, The People's Hospital of Baise, Baise, Guangxi, PR People's Republic of China
| | - Weijie Zhou
- Clinical Laboratory, The People's Hospital of Baise, Baise, Guangxi, PR People's Republic of China
| | - Mingkui Peng
- Laboratory of Medical Genetics, Qinzhou Maternal and Child Health Care Hospital, Qinzhou, Guangxi, PR People's Republic of China
| | - Ju Long
- Laboratory of Medical Genetics, Qinzhou Maternal and Child Health Care Hospital, Qinzhou, Guangxi, PR People's Republic of China
| | - Wangrong Wen
- Clinical Laboratory, The Affiliated Shunde Hospital of Jinan University, Foshan, Guangdong, PR People's Republic of China
- Clinical Laboratory Center, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, PR People's Republic of China
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Novel Decision Tool for More Severe α-Thalassemia Genotypes Screening with Functional Loss of Two or More α-Globin Genes: A Diagnostic Test Study. Diagnostics (Basel) 2022; 12:diagnostics12123008. [PMID: 36553015 PMCID: PMC9777031 DOI: 10.3390/diagnostics12123008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 11/16/2022] [Accepted: 11/22/2022] [Indexed: 12/04/2022] Open
Abstract
After the exclusion of iron deficiency and β-thalassemia, molecular research for α-thalassemia is recommended to investigate microcytic anemia. Aiming to suggest more efficiently the molecular analysis for individuals with a greater chance of having a symptomatic form of the disease, we have developed and validated a new decision tool to predict the presence of two or more deletions of α-thalassemia, increasing considerably the pre-test probability. The model was created using the variables: the percentage of HbA2, serum ferritin and mean corpuscular volume standardized by age. The model was trained in 134 patients and validated in 160 randomly selected patients from the total sample. We used Youden's index applied to the ROC curve methodology to establish the optimal odds ratio (OR) cut-off for the presence of two or more α-globin gene deletions. Using the OR cut-off of 0.4, the model's negative predictive value (NPV) was 96.8%; the cut-off point accuracy was 85.4%; and the molecular analysis pre-test probability increased from 25.9% to 65.4% after the use of the proposed model. This tool aims to assist the physician in deciding when to perform molecular studies for the diagnosis of α-thalassemia. The model is useful in places with few financial health resources.
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Phirom K, Charoenkwan P, Shoombuatong W, Charoenkwan P, Sirichotiyakul S, Tongsong T. DeepThal: A Deep Learning-Based Framework for the Large-Scale Prediction of the α +-Thalassemia Trait Using Red Blood Cell Parameters. J Clin Med 2022; 11:jcm11216305. [PMID: 36362531 PMCID: PMC9654007 DOI: 10.3390/jcm11216305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 10/16/2022] [Accepted: 10/23/2022] [Indexed: 11/16/2022] Open
Abstract
Objectives: To develop a machine learning (ML)-based framework using red blood cell (RBC) parameters for the prediction of the α+-thalassemia trait (α+-thal trait) and to compare the diagnostic performance with a conventional method using a single RBC parameter or a combination of RBC parameters. Methods: A retrospective study was conducted on possible couples at risk for fetus with hemoglobin H (Hb H disease). Subjects with molecularly confirmed normal status (not thalassemia), α+-thal trait, and two-allele α-thalassemia mutation were included. Clinical parameters (age and gender) and RBC parameters (Hb, Hct, MCV, MCH, MCHC, RDW, and RBC count) obtained from their antenatal thalassemia screen were retrieved and analyzed using a machine learning (ML)-based framework and a conventional method. The performance of α+-thal trait prediction was evaluated. Results: In total, 594 cases (female/male: 330/264, mean age: 29.7 ± 6.6 years) were included in the analysis. There were 229 normal controls, 160 cases with the α+-thalassemia trait, and 205 cases in the two-allele α-thalassemia mutation category, respectively. The ML-derived model improved the diagnostic performance, giving a sensitivity of 80% and specificity of 81%. The experimental results indicated that DeepThal achieved a better performance compared with other ML-based methods in terms of the independent test dataset, with an accuracy of 80.77%, sensitivity of 70.59%, and the Matthews correlation coefficient (MCC) of 0.608. Of all the red blood cell parameters, MCH < 28.95 pg as a single parameter had the highest performance in predicting the α+-thal trait with the AUC of 0.857 and 95% CI of 0.816−0.899. The combination model derived from the binary logistic regression analysis exhibited improved performance with the AUC of 0.868 and 95% CI of 0.830−0.906, giving a sensitivity of 80.1% and specificity of 75.1%. Conclusions: The performance of DeepThal in terms of the independent test dataset is sufficient to demonstrate that DeepThal is capable of accurately predicting the α+-thal trait. It is anticipated that DeepThal will be a useful tool for the scientific community in the large-scale prediction of the α+-thal trait.
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Affiliation(s)
- Krittaya Phirom
- Department of Obstetrics and Gynecology, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Phasit Charoenkwan
- Modern Management and Information Technology, College of Arts, Media and Technology, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Watshara Shoombuatong
- Center of Data Mining and Biomedical Informatics, Faculty of Medical Technology, Mahidol University, Bangkok 10700, Thailand
| | - Pimlak Charoenkwan
- Department of Pediatrics, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand
- Thalassemia and Hematology Center, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Supatra Sirichotiyakul
- Department of Obstetrics and Gynecology, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand
- Thalassemia and Hematology Center, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand
- Correspondence: (S.S.); (T.T.)
| | - Theera Tongsong
- Department of Obstetrics and Gynecology, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand
- Thalassemia and Hematology Center, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200, Thailand
- Correspondence: (S.S.); (T.T.)
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Zulkafli Z, Azlan M, Abu Za'ror YM, Mat Ghani SA, Bakar N. Detection of BCL11A, HMIP, and XmnI polymorphisms among anemic pregnant women in hospital Universiti Sains Malaysia. JOURNAL OF APPLIED HEMATOLOGY 2022. [DOI: 10.4103/joah.joah_22_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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Mattar CNZ, Labude MK, Lee TN, Lai PS. Ethical considerations of preconception and prenatal gene modification in the embryo and fetus. Hum Reprod 2021; 36:3018-3027. [PMID: 34665851 DOI: 10.1093/humrep/deab222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 09/08/2021] [Indexed: 11/13/2022] Open
Abstract
The National Academies of Sciences and Medicine 2020 consensus statement advocates the reinstatement of research in preconception heritable human genome editing (HHGE), despite the ethical concerns that have been voiced about interventions in the germline, and outlines criteria for its eventual clinical application to address monogenic disorders. However, the statement does not give adequate consideration to alternative technologies. Importantly, it omits comparison to fetal gene therapy (FGT), which involves gene modification applied prenatally to the developing fetus and which is better researched and less ethically contentious. While both technologies are applicable to the same monogenic diseases causing significant prenatal or early childhood morbidity, the benefits and risks of HHGE are distinct from FGT though there are important overlaps. FGT has the current advantage of a wealth of robust preclinical data, while HHGE is nascent technology and its feasibility for specific diseases still requires scientific proof. The ethical concerns surrounding each are unique and deserving of further discussion, as there are compelling arguments supporting research and eventual clinical translation of both technologies. In this Opinion, we consider HHGE and FGT through technical and ethical lenses, applying common ethical principles to provide a sense of their feasibility and acceptability. Currently, FGT is in a more advanced position for clinical translation and may be less ethically contentious than HHGE, so it deserves to be considered as an alternative therapy in further discussions on HHGE implementation.
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Affiliation(s)
- Citra Nurfarah Zaini Mattar
- Experimental Fetal Medicine Group, Department of Obstetrics and Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,Department of Obstetrics and Gynaecology, National University Health System, Singapore, Singapore
| | - Markus Klaus Labude
- Science, Health and Policy-Relevant Ethics in Singapore (SHAPES) Initiative, Centre for Biomedical Ethics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Timothy Nicholas Lee
- Science, Health and Policy-Relevant Ethics in Singapore (SHAPES) Initiative, Centre for Biomedical Ethics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Poh San Lai
- Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
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Liang Q, Gu W, Chen P, Li Y, Liu Y, Tian M, Zhou Q, Qi H, Zhang Y, He J, Li Q, Tang L, Tang J, Teng Y, Zhou Y, Huang S, Lu Z, Xu M, Hou W, Huang T, Li Y, Li R, Hu L, Li S, Guo Q, Zhuo Z, Mou Y, Cram DS, Wu L. A More Universal Approach to Comprehensive Analysis of Thalassemia Alleles (CATSA). J Mol Diagn 2021; 23:1195-1204. [PMID: 34293487 DOI: 10.1016/j.jmoldx.2021.06.008] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 03/24/2021] [Accepted: 06/10/2021] [Indexed: 11/18/2022] Open
Abstract
The aim of the study was to assess the clinical utility of a third-generation sequencing (TGS) approach termed comprehensive analysis of thalassemia alleles (CATSA) for identifying both α and β thalassemia genetic carrier status. Prospective blood samples (n = 1759) with abnormal hemoglobin parameters were screened for pathogenic thalassemia variants by CATSA on the PacBio TGS platform. In 1159 individuals, a total of 1317 pathogenic thalassemia variants were identified and confirmed by independent PCR-based tests. Of the total thalassemia variants detected, the α-variant --SEA (35.4%) and β-variant c.126_129delCTTT (15%) were the most common. CATSA was also able to detect three types of rare HBA structural variants as well as five rare HBA2, three HBA1, and 10 HBB single-nucleotide variations/insertions and deletions. Compared with standard thalassemia variant PCR panel testing, CATSA identified all panel variants present, with no false-negative results. Carrier assignment was improved through identification of rare variants missed by the panel test. On the basis of allelic coverage, reliability, and accuracy, TGS with long-range PCR presents a comprehensive approach with the potential to provide a universal solution for thalassemia genetic carrier screening. It is proposed that CATSA has immediate clinical utility as an effective carrier screening approach for at-risk couples.
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Affiliation(s)
- Qiaowei Liang
- Department of Molecular Genetics, Hunan Jiahui Genetics Hospital, Changsha, China
| | - Wanqian Gu
- Department of Reproductive Genetics, Yunnan Maternal and Child Health Care Hospital, Kunming, China
| | - Ping Chen
- Key Laboratory of Thalassemia Medicine, Chinese Academy of Medical Sciences, Guangxi Key Laboratory of Thalassemia Research, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | | | - Yanqiu Liu
- Prenatal Diagnosis Center, Jiangxi Maternal and Child Health Hospital, Nanchang, China
| | - Mao Tian
- Center for Medical Genetic and Prenatal Diagnosis, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
| | - Qiaomiao Zhou
- Department of Genetics and Prenatal Diagnosis, Hainan Women and Children's Medical Center, Haikou, China
| | - Hongbo Qi
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Yuhong Zhang
- The Center for Clinical Molecular Medical Detection, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Jun He
- Department of Molecular Genetics, Changsha Hospital for Maternal and Child Health Care Genetic Eugenics, Changsha, China
| | - Qing Li
- Department of Obstetrics and Gynecology, Key Laboratory for Major Obstetric Diseases of Guangdong Province, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Lingfang Tang
- Department of Pregnancy Health, Guilin Women and Children Health Care Hospital, Guilin, China
| | - Juan Tang
- Laboratory of Genetics and Metabolism, Guilin Women and Children Health Care Hospital, Guilin, China
| | - Yanling Teng
- Department of Molecular Genetics, Hunan Jiahui Genetics Hospital, Changsha, China
| | - Yulin Zhou
- United Diagnostic and Research Center for Clinical Genetics, Women and Children's Hospital, School of Medicine and School of Public Health, Xiamen University, Xiamen, China
| | - Shengwen Huang
- Department of Genetics and Prenatal Diagnosis, Guizhou Provincial People's Hospital, Guiyang, China
| | - Zongjie Lu
- Department of Obstetrics, Suining Central Hospital, Suining, China
| | | | - Wei Hou
- Key Laboratory of Thalassemia Medicine, Chinese Academy of Medical Sciences, Guangxi Key Laboratory of Thalassemia Research, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Ting Huang
- Prenatal Diagnosis Center, Jiangxi Maternal and Child Health Hospital, Nanchang, China
| | - Youqiong Li
- Center for Medical Genetic and Prenatal Diagnosis, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
| | - Rong Li
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Lanping Hu
- Department of Molecular Genetics, Changsha Hospital for Maternal and Child Health Care Genetic Eugenics, Changsha, China
| | - Shaoying Li
- Department of Obstetrics and Gynecology, Key Laboratory for Major Obstetric Diseases of Guangdong Province, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Qiwei Guo
- United Diagnostic and Research Center for Clinical Genetics, Women and Children's Hospital, School of Medicine and School of Public Health, Xiamen University, Xiamen, China
| | - Zhaozhen Zhuo
- Department of Genetics and Prenatal Diagnosis, Guizhou Provincial People's Hospital, Guiyang, China
| | - Yan Mou
- Department of Obstetrics, Suining Central Hospital, Suining, China
| | | | - Lingqian Wu
- Department of Molecular Genetics, Hunan Jiahui Genetics Hospital, Changsha, China; Center for Medical Genetics and Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, China.
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11
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Mosca A, Paleari R, Harteveld CL. A roadmap for the standardization of hemoglobin A 2. Clin Chim Acta 2021; 512:185-190. [PMID: 33181152 DOI: 10.1016/j.cca.2020.11.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 10/12/2020] [Accepted: 11/06/2020] [Indexed: 11/30/2022]
Abstract
BACKGROUND Standardization of laboratory tests can be a long process, and this is the case with regards to the methods used to measure hemoglobin A2 (HbA2), an important marker for beta-thalassemia and other thalassemic conditions. The IFCC standardization project started in 2004, and it took at least 15 years before developing a reference measurement procedure, defining and producing calibrators and certified reference materials. METHODS A series of steps have to be undertaken in order to promote the standardization in the field, a process involving a number of stakeholders (manufacturers, scientific societies, national health bodies, laboratory professionals, clinicians). In this work we describe some possible process indicators, in order to assure that the standardization will have internal and external validity and be effective for a long time. These indicators concern the inter-method studies, elaboration of External Quality Assessment Schemes, and the evaluation of the yearly distributions of HbA2 measurements collected in selected laboratories. RESULTS Preliminary results are reported concerning the yearly distributions of HbA2, collected in two different locations, and using different analytical methods. Median yearly values were found very constant over the years, but different between methods. On the other side, results obtained on the same specimens using two different techniques, proved that results by capillary electrophoresis in 2 out of the 3 years of observation, were significantly lower than those by HPLC. CONCLUSION In this document we report what has been done so far, and what has to be done to achieve the standardization of the measurement of HbA2 worldwide.
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Affiliation(s)
- Andrea Mosca
- Dip. di Fisiopatologia Medico-Chirurgica e dei Trapianti and Centro per la Riferibilità Metrologica in Medicina di Laboratorio (CIRME), Università degli Studi di Milano, Milano, Italy; Istituto di Tecnologie Biomediche, Consiglio Nazionale delle Ricerche (ITB-CNR), Milano, Italy.
| | - Renata Paleari
- Dip. di Fisiopatologia Medico-Chirurgica e dei Trapianti and Centro per la Riferibilità Metrologica in Medicina di Laboratorio (CIRME), Università degli Studi di Milano, Milano, Italy; Istituto di Tecnologie Biomediche, Consiglio Nazionale delle Ricerche (ITB-CNR), Milano, Italy
| | - Cornelis L Harteveld
- Dept. of Clinical Genetics/LDGA, Leiden University Medical Center, Leiden, the Netherlands
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12
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Qian H, Huang J, Xu J, Zhao W, Ye X, Liu W. Prenatal diagnosis of a rare β-thalassemia gene -90 (C>T) (HBB: c.-140 C>T) mutation associated with deletional Hb H disease (-- SEA /-α 4.2 ). Mol Genet Genomic Med 2020; 8:e1472. [PMID: 32885601 PMCID: PMC7667371 DOI: 10.1002/mgg3.1472] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Revised: 08/06/2020] [Accepted: 08/07/2020] [Indexed: 12/13/2022] Open
Abstract
Background Hemoglobin H (Hb H) disease can be caused by compound heterozygosity for two different mutations or from homozygotes for mutations, and conventional genetic methods may lead to misdiagnosis when Hb H disease is combined with a rare β‐thalassemia. Methods Hematology parameters and hemoglobin electrophoresis analysis, gap‐polymerase chain reaction (gap‐PCR) and reverse dot‐blot hybridization (RDB‐PCR) were employed to identify common α‐thalassemia and Hb H disease. Rare β‐thalassemia mutations were detected by DNA sequencing. Results Hematological analysis and hemoglobin electrophoresis revealed a mild anemia α0‐thalassemia trait (Hb 90 g/L, MCV 71 fL, and MCH 22.7 pg) compound with β+‐thalassemia trait (MCV 71 fL, MCH 22.7 pg, and HbA2 5.51%) for the pregnant woman. DNA sequencing for the β‐globin gene revealed rare a -90 (C>T) (HBB: c.‐140 C>T) mutation for the woman. DNA analysis identified that the fetus inherited the α0‐thalassemia mutation [‐‐SEA (Southeast Asian)] and a rare β+‐thalassemia mutation -90 (C>T) (HBB: c.‐140 C>T) from the mother, and the α+‐thalassemia mutation [‐α4.2 (leftward)] from the father. Conclusion We reported a rare -90 (C>T) (HBB: c.‐140 C>T) mutation combined with the ‐‐SEA/‐α4.2 in a family. This finding enriched the mutation spectrum of thalassemia molecular characteristics in China and emphasized the significance in DNA sequencing in mutation screening for the families with thalassemia.
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Affiliation(s)
- Hou Qian
- The Medical Genetics & Molecular Diagnosis Laboratory, Shenzhen, China.,Prenatal Diagnosis Center, Shenzhen, China.,Department of Obstetrics, Shenzhen Second People's Hospital/the First Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen, China
| | - Jianlin Huang
- The Medical Genetics & Molecular Diagnosis Laboratory, Shenzhen, China.,Prenatal Diagnosis Center, Shenzhen, China.,Department of Obstetrics, Shenzhen Second People's Hospital/the First Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen, China
| | - Ji Xu
- The Medical Genetics & Molecular Diagnosis Laboratory, Shenzhen, China.,Prenatal Diagnosis Center, Shenzhen, China.,Department of Obstetrics, Shenzhen Second People's Hospital/the First Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen, China
| | - Weihua Zhao
- Prenatal Diagnosis Center, Shenzhen, China.,Department of Obstetrics, Shenzhen Second People's Hospital/the First Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen, China
| | - Xiufeng Ye
- The Medical Genetics & Molecular Diagnosis Laboratory, Shenzhen, China.,Prenatal Diagnosis Center, Shenzhen, China.,Department of Obstetrics, Shenzhen Second People's Hospital/the First Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen, China
| | - Wenlan Liu
- The Medical Genetics & Molecular Diagnosis Laboratory, Shenzhen, China.,Prenatal Diagnosis Center, Shenzhen, China.,Department of Obstetrics, Shenzhen Second People's Hospital/the First Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen, China
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13
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Xu L, Mao A, Liu H, Gui B, Choy KW, Huang H, Yu Q, Zhang X, Chen M, Lin N, Chen L, Han J, Wang Y, Zhang M, Li X, He D, Lin Y, Zhang J, Cram DS, Cao H. Long-Molecule Sequencing. J Mol Diagn 2020; 22:1087-1095. [DOI: 10.1016/j.jmoldx.2020.05.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 04/22/2020] [Accepted: 05/19/2020] [Indexed: 01/04/2023] Open
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14
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Mortazavipour MM, Shahbazi S, Mahdian R. Detection of Paternal IVS-II-1 (G>A) ( HBB: c.315+1G>A) Mutation in Cell-Free Fetal DNA Using COLD-PCR assay. Hemoglobin 2020; 44:168-173. [PMID: 32703054 DOI: 10.1080/03630269.2020.1768864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Standardization of noninvasive prenatal diagnosis (PND) method that can identify common mutations in the population is of great value. The purpose of this study was to find the paternal HBB gene IVS-II-1 (G>A) (HBB: c.315+1G>A) mutation in maternal plasma cell-free DNA using the co-amplification at lower denaturation temperature-polymerase chain reaction (COLD-PCR) method. We designed simulated circulating free DNA (cfDNA) in maternal plasma to optimize the COLD-PCR assay. Peripheral blood samples were collected from normal and IVS-II-1 heterozygous individuals as well as five heterozygous pregnant women whose husbands were carriers of IVS-II-1. The cfDNA was extracted from the plasma and subjected to optimized COLD-PCR followed by Sanger sequencing. The optimized protocol was tested on simulated cfDNA samples with proportions of 8.0, 6.0, 4.0 and 2.0%, and the results showed that the COLD-PCR is informative on samples containing 8.0% mutant alleles and above. The patients were undergoing invasive PND procedures via chorionic villi sampling (CVS) as scheduled at the 12th week of gestation. Paternal IVS-II-1 was detected in cfDNA samples of three patients who were in complete concordance with the outcome of CVS. Despite the limitations of the COLD-PCR method in noninvasive PND, it can be considered as a cost-effective screening option. The use of this approach for screening at-risk patients can prevent unnecessary invasive procedures identifying common mutations in high-prevalence diseases.
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Affiliation(s)
- Mohamad M Mortazavipour
- Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Shirin Shahbazi
- Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Reza Mahdian
- Molecular Medicine Department, Pasteur Institute of Iran, Tehran, Iran
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15
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Risoluti R, Caprari P, Gullifa G, Massimi S, Maffei L, Sorrentino F, Carcassi E, Materazzi S. An Innovative Multilevel Test for Hemoglobinopathies: TGA/Chemometrics Simultaneously Identifies and Classifies Sickle Cell Disease From Thalassemia. Front Mol Biosci 2020; 7:141. [PMID: 32850950 PMCID: PMC7396684 DOI: 10.3389/fmolb.2020.00141] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 06/10/2020] [Indexed: 11/13/2022] Open
Abstract
Introduction: Hemoglobinopathies are the most common genetic disorder wordlwide and because of migrations are become an emerging global health problem. Screening programmes for Sickle cell disease and Thalassemia have been implemented in some countries, but are not a common practice, due to a lack in the accuracy of the methods and to the costs of the analyses. Objectives: The objective of this study was the application of the thermogravimetry coupled to chemometrics as new screening method to perform an early diagnosis of thalassemia and sickle cell disease. Methods: Whole blood samples (30 μL) from sickle cell anemia and thalassemia patients were analyzed using the thermobalance TG7 and the resulting curves were compared with those of healthy individuals. A chemometric approach based on Principal Components Analysis (PCA) was exploited to enhance correlation between thermogravimetric profiles and a model of prediction by Partial Least Square Discriminant Analysis (PLS-DA) was developed and validated. Results: The characteristic profile of the blood sample thermal decomposition and the first derivative of the TG curve showed that patients were clearly distinguished from healthy individuals as a result of different amounts of water and corpuscular fraction of blood. The chemometric approach based on PCA allowed a quick identification of differences between healthy subjects and patients and also between thalassemic and sickle cell anemia subjects. Chemometric tools (PLS-DA) were used to validate a model of prediction to process the thermogravimetric curves and to obtain in 1 h an accurate diagnosis. The TGA/Chemometric test permitted to perform first level test for hemoglobinopathies with the same accuracy of confirmatory analyses obtained by the molecular investigation. Conclusions: A screening test based on the coupling of thermogravimetry and chemometrics was optimized for the differential diagnosis of hemoglobinopathies. The novel test is able to simultaneously perform a simple and fast diagnosis of sickle cell anemia or thalassemia, in a single analysis of few microliters of non-pretreated whole blood at low cost, and with high accuracy. Moreover this method results particularly suitable in pediatric patients as it requires small sample volumes and is able to characterize also transfused patients.
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Affiliation(s)
- Roberta Risoluti
- Department of Chemistry, Sapienza - University of Rome, Rome, Italy
| | - Patrizia Caprari
- National Centre for the Control and Evaluation of Medicines, Istituto Superiore di Sanità, Rome, Italy
| | | | - Sara Massimi
- National Centre for the Control and Evaluation of Medicines, Istituto Superiore di Sanità, Rome, Italy
| | - Laura Maffei
- Thalassemia Unit, S. Eugenio Hospital, Rome, Italy
| | | | - Elena Carcassi
- Department of Chemistry, Sapienza - University of Rome, Rome, Italy
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16
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Zhou Y, Zhang J, Wang C, Zhou L, Zhou L, Ou D, Peng D. Application of HbA 2 levels and red cell indices-based new model in the differentiation of thalassemia traits from iron deficiency in hypochromic microcytic anemia Cases. Int J Lab Hematol 2020; 42:526-532. [PMID: 32564505 DOI: 10.1111/ijlh.13270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 05/18/2020] [Accepted: 05/31/2020] [Indexed: 11/28/2022]
Abstract
INTRODUCTION Thalassemia traits and iron deficiency anemia are the most common types of hypochromic microcytic anemia with similar clinical and laboratory features. It is vital to establish a new screening model based on HbA2 levels and red cell indices for the differentiation of TT from IDA in hypochromic microcytic anemia cases. METHOD The data comprised of the red blood cell indices and HbA2 prenatal diagnostic test results of 810 individuals who were identified to conform to the following criteria: MCV < 80 fl or MCH < 26 pg. We launched a new model consisting mainly of significative red cell indices and HbA2 levels, as well as proposing cutoff values by using decision trees and logistic regression analyses. Next, we evaluated our new method by comparing the sensitivity, specificity, positive, and negative predictive values with those of the previous formulas. RESULTS We put forward a new model and compared it with 5 efficient formulas. The new model exhibited the highest accuracy (0.918), with its sensitivity and specificity calculated as 0.917 and 0.921, respectively. Our new model's Youden index was 0.838, which is higher than the other formulas' Youden indices. CONCLUSIONS The new screening model, based on HbA2 levels and red cell indices, is suitable for the screening of thalassemia patients in the hypochromic microcytic anemia group and has the best efficiency in distinguishing TT and IDA.
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Affiliation(s)
- Yuan Zhou
- The First People's Hospital of Changde, Changde, China
| | - Jibo Zhang
- The First People's Hospital of Changde, Changde, China
| | - Chao Wang
- The First People's Hospital of Changde, Changde, China
| | - Lihua Zhou
- The First People's Hospital of Changde, Changde, China
| | - Lu Zhou
- The First People's Hospital of Changde, Changde, China
| | - Dan Ou
- Changde Hospital of University of South China, Changde, China
| | - Dan Peng
- The First People's Hospital of Changde, Changde, China.,Changde Hospital of University of South China, Changde, China
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17
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Noor FA, Sultana N, Bhuyan GS, Islam MT, Hossain M, Sarker SK, Islam K, Khan WA, Rahman M, Qadri SK, Shekhar HU, Qadri F, Qadri SS, Mannoor K. Nationwide carrier detection and molecular characterization of β-thalassemia and hemoglobin E variants in Bangladeshi population. Orphanet J Rare Dis 2020; 15:15. [PMID: 31941534 PMCID: PMC6961315 DOI: 10.1186/s13023-020-1294-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 01/02/2020] [Indexed: 12/30/2022] Open
Abstract
Background ß-thalassemia is one of the most common inherited blood disorders in the world and a major deterrent to the public health of Bangladesh. The management of thalassemia patients requires lifelong frequent blood transfusion and the available treatment options are unsatisfactory. A national policy on thalassemia prevention is mandatory in Bangladesh. However, precise and up-to-date information on the frequency of ß-thalassemia carriers are missing due to lack of accurate diagnostic approaches, limited access to information and absence of national screening program. This study aims to determine the nationwide carrier frequency of hemoglobin E (HbE) and β- thalassemia and mutation spectrum among the carriers using molecular, hematological and biochemical methods. Methods The study enrolled a total of 1877 individuals (60.1% male and 39.9% female) aged between 18 and 35 years. Total sample size and its division-wise breakdown were calculated in proportion to national and division-wise population. Venous blood was collected and subjected to CBC analysis and Hb-electrophoresis for each participant. Serum ferritin was measured to detect coexistence of iron deficiency anemia with thalassemia carrier. DNA-based High Resolution Melting (HRM) curve analysis was performed for confirmation of carrier status by mutation detection. Results Of 11.89% (95% CI, 10.43–13.35) carriers of β-globin gene mutations, 8.68% (95% CI, 7.41–9.95) had HbE trait (ETT) and 2.24% (95% CI, 1.57–2.91) had beta-thalassemia trait (BTT). Among eight divisions, Rangpur had the highest carrier frequency of 27.1% (ETT-25%, BTT-2.1%), whereas Khulna had the lowest frequency of 4.2% (ETT-4.2% only). Moreover, α- thalassemia, HbD trait, HbE disease, hereditary persistence of HbF were detected in 0.11, 0.16, 0.43 and 0.16% participants, respectively. HRM could identify two individuals with reported pathogenic mutations in both alleles who were erroneously interpreted as carriers by hematological indices. Finally, a total of nine different mutations including a novel mutation (c.151A > G) were detected in the β-globin gene. Conclusions Since carrier frequency for both HbE and β-thalassemia is alarmingly high in Bangladesh, a nationwide awareness and prevention program should be made mandatory to halt the current deteriorating situations. Mutation-based confirmation is highly recommended for the inconclusive cases with conventional carrier screening methods to avoid any faulty detection of thalassemia carriers.
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Affiliation(s)
- Farjana Akther Noor
- Laboratory of Genetics and Genomics, Institute for Developing Science and Health Initiatives, Mohakhali, Dhaka, 1212, Bangladesh.,Department of Biochemistry and Molecular Biology, University of Dhaka, Shahbagh, Dhaka, 1000, Bangladesh
| | - Nusrat Sultana
- Laboratory of Genetics and Genomics, Institute for Developing Science and Health Initiatives, Mohakhali, Dhaka, 1212, Bangladesh.,Department of Virology, Dhaka Medical College Hospital, Shahbagh, Dhaka, 1000, Bangladesh
| | - Golam Sarower Bhuyan
- Laboratory of Genetics and Genomics, Institute for Developing Science and Health Initiatives, Mohakhali, Dhaka, 1212, Bangladesh
| | - Md Tarikul Islam
- Laboratory of Genetics and Genomics, Institute for Developing Science and Health Initiatives, Mohakhali, Dhaka, 1212, Bangladesh
| | - Mohabbat Hossain
- Laboratory of Genetics and Genomics, Institute for Developing Science and Health Initiatives, Mohakhali, Dhaka, 1212, Bangladesh
| | - Suprovath Kumar Sarker
- Laboratory of Genetics and Genomics, Institute for Developing Science and Health Initiatives, Mohakhali, Dhaka, 1212, Bangladesh
| | - Khaleda Islam
- Directorate General of Health Services, MoHFW, Government of Bangladesh, Mohakhali, Dhaka, 1212, Bangladesh
| | - Waqar Ahmed Khan
- Department of Biochemistry and Molecular Biology, Dhaka Shishu Hospital, Sher-e-Bangla Nagar, Dhaka, 1207, Bangladesh
| | - Mujahida Rahman
- Department of Hematology, Bangabandhu Sheikh Mujib Medical University, Shahbagh, Dhaka, 1000, Bangladesh
| | - Syeda Kashfi Qadri
- Department of Pediatric Medicine, KK Women's and Children's Hospital, 100 Bukit Timah Road, Singapore, Singapore
| | - Hossain Uddin Shekhar
- Department of Biochemistry and Molecular Biology, University of Dhaka, Shahbagh, Dhaka, 1000, Bangladesh
| | - Firdausi Qadri
- Laboratory of Genetics and Genomics, Institute for Developing Science and Health Initiatives, Mohakhali, Dhaka, 1212, Bangladesh.,Department of Enteric and Respiratory Infectious Diseases, Infectious Diseases Division, International Centre for Diarrhoeal Disease Research, Mohakhali, Dhaka, 1212, Bangladesh
| | - Syed Saleheen Qadri
- Laboratory of Genetics and Genomics, Institute for Developing Science and Health Initiatives, Mohakhali, Dhaka, 1212, Bangladesh
| | - Kaiissar Mannoor
- Laboratory of Genetics and Genomics, Institute for Developing Science and Health Initiatives, Mohakhali, Dhaka, 1212, Bangladesh.
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Abstract
Next generation DNA sequencing (NGS) has the potential to improve the diagnostic and prognostic utility of newborn screening programmes. This study assesses the feasibility of automating NGS on dried blood spot (DBS) DNA in a United Kingdom National Health Service (UK NHS) laboratory. An NGS panel targeting the entire coding sequence of five genes relevant to disorders currently screened for in newborns in the UK was validated on DBS DNA. An automated process for DNA extraction, NGS and bioinformatics analysis was developed. The process was tested on DBS to determine feasibility, turnaround time and cost. The analytical sensitivity of the assay was 100% and analytical specificity was 99.96%, with a mean 99.5% concordance of variant calls between DBS and venous blood samples in regions with ≥30× coverage (96.8% across all regions; all variant calls were single nucleotide variants (SNVs), with indel performance not assessed). The pipeline enabled processing of up to 1000 samples a week with a turnaround time of four days from receipt of sample to reporting. This study concluded that it is feasible to automate targeted NGS on routine DBS samples in a UK NHS laboratory setting, but it may not currently be cost effective as a first line test.
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Chakravorty S, Dick MC. Antenatal screening for haemoglobinopathies: current status, barriers and ethics. Br J Haematol 2019; 187:431-440. [PMID: 31509241 DOI: 10.1111/bjh.16188] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Sickle cell disease (SCD) and thalassaemia are genetic disorders that are caused by errors in the genes for haemoglobin and are some of the most common significant genetic disorders in the world, resulting in significant morbidity and mortality. Great disparities exist in the outcome of these conditions between resource- rich and resource-poor nations. Antenatal screening for these disorders aims to provide couples with information about their reproductive risk and enable them to make informed reproductive choices; ultimately reducing the likelihood of children being born with these conditions. This review provides an overview of the current status of antenatal, pre-marital and population screening of SCD and thalassaemia in countries with both high-and low prevalence of these conditions, methods of screening in use, and discusses some of the pitfalls, ethical issues and controversies surrounding antenatal screening. It also discusses outcomes of some screening programmes and recognises the need for the establishment of antenatal screening in areas where their prevalence is highest; namely sub-Saharan Africa and India.
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Affiliation(s)
| | - Moira C Dick
- Paediatric Haematology, King's College Hospital, London, UK
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20
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Pornprasert S, Tookjai M, Punyamung M, Kongthai K. A Formula to Identify Potential Cases of β-Thalassemia/HbE Disease Among Patients With Absent HbA, HbE >75% and HbF Between 5 and 15. Lab Med 2019; 50:158-162. [PMID: 30239825 DOI: 10.1093/labmed/lmy058] [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: 11/13/2022] Open
Abstract
OBJECTIVE To establish a simple formula to be used for discrimination between β-thalassemia/hemoglobin E (β-thal/HbE) and homozygous hemoglobin (Hb)E in specimens with absent hemoglobin (Hb)A, HbE of greater than 75%, and HbF between 5% and 15%. METHODS We analyzed laboratory results from February 2015 through February 2018. Molecular analysis for diagnosis of β-thal mutation and HbE was performed in specimens that contained HbE of greater than 75% and HbF from 5% to 15%, as measured by high-performance liquid chromatography (HPLC). HbA2 and HbF levels were also measured by capillary electrophoresis. Then, the formula (6 × HbA2 + HbF)/MCV was developed. RESULTS The score of 0.9 or higher was found in all 19 β-thal/HbE specimens (100%) and only 8 of 65 homozygous HbE specimens (12.3%). Also, the formula yielded 90.5% efficiency in identifying β-thal/HbE disease, and the efficiency was found to be higher compared with when the HbA2 value of greater than 6% was used by itself (85.4%). CONCLUSION The formula (6 × HbA2 + HbF)/MCV, with a cutoff point at 0.9, could identify the potential cases of β-thal/HbE disease among patients with absent HbA, HbE of greater than 75%, and HbF between 5% and 15%.
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Affiliation(s)
- Sakorn Pornprasert
- Department of Medical Technology, Faculty of Associated Medical Sciences and Chiang Mai University, Thailand
| | - Monthathip Tookjai
- Associated Medical Sciences Clinical Service Center, Faculty of Associated Medical Sciences and Chiang Mai University, Thailand
| | - Manoo Punyamung
- Associated Medical Sciences Clinical Service Center, Faculty of Associated Medical Sciences and Chiang Mai University, Thailand
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21
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Lee SY, Yap ES, Lee EYP, Goh JH, Liu TC, Yip C. Evaluation of Thalassaemia Screening Tests in the Antenatal and Non-Antenatal Populations in Singapore. ANNALS OF THE ACADEMY OF MEDICINE, SINGAPORE 2019. [DOI: 10.47102/annals-acadmedsg.v48n1p5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Introduction: Haemoglobinopathy testing is performed for carrier screening and evaluation of microcytic anaemia. We evaluated the effectiveness of thalassaemia screening tests at our institution and suggest ways of improving the testing algorithm. Materials and Methods: A total of 10,084 non-antenatal and 11,364 antenatal samples with alkaline gel electrophoresis (AGE), capillary electrophoresis (CE), haemoglobin H (HbH) inclusion test, mean corpuscular haemoglobin (MCH) and mean corpuscular volume (MCV) were retrospectively reviewed. A subgroup of 187 samples with genetic testing was correlated with HbH inclusions and MCH/MCV. The effect of iron deficiency on percentage haemoglobin A2 (HbA2) was studied. Results: HbH inclusion test showed low sensitivity of 21.43% for α-thalassaemia mutations but higher sensitivity of 78.95% for --SEA deletion. Byreceiver operating characteristic (ROC) analysis, MCH ≤28 pg or MCV ≤80 fl for non-antenatal samples and MCH ≤27 pg or MCV ≤81 fl for antenatal samples had >98% sensitivity for HbH inclusions. Above these thresholds, the probability that HbH inclusions would be absent was >99% (negative predictive value [NPV] >99%). MCH ≤28 pg had 100% sensitivity (95% CI 95.63%-100%) for α-thalassaemia mutations and 97.68% calculated NPV in the antenatal population. Detection of haemoglobin variants by CE correlated highly with AGE (99.89% sensitivity, 100% specificity). Severe iron deficiency reduced HbA2 in haemoglobin E (P <0.001) and α-thalassaemia (P = 0.0035), but not in β-thalassaemia. Conclusion: MCH/MCV thresholds have adequate sensitivity for α-thalassaemia in the antenatal population, and genotyping plays an important role as HbH inclusion test shows low sensitivity. CE without AGE, may be used as initial screening for haemoglobin variants. Our study provides contemporary data to guide thalassaemia screening algorithms in Singapore.
Key words: Haemoglobinopathy, Mean corpuscular haemoglobin, Mean corpuscular volume
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22
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Viprakasit V, Ekwattanakit S. Clinical Classification, Screening and Diagnosis for Thalassemia. Hematol Oncol Clin North Am 2018; 32:193-211. [PMID: 29458726 DOI: 10.1016/j.hoc.2017.11.006] [Citation(s) in RCA: 102] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
At present, thalassemia diseases are classified into transfusion-dependent thalassemia and non-transfusion-dependent thalassemia. This classification is based on the clinical severity of patients determining whether they do require regular blood transfusions to survive (transfusion-dependent thalassemia) or not (non-transfusion-dependent thalassemia). In addition to the previous terminology of "thalassemia major" or "thalassemia intermedia," this classification has embraced all other forms of thalassemia syndromes such as α-thalassemia, hemoglobin E/β-thalassemia and combined α- and β-thalassemias. Definitive diagnosis of thalassemia and hemoglobinopathies requires a comprehensive workup from complete blood count, hemoglobin analysis, and molecular studies to identify mutations of globin genes.
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Affiliation(s)
- Vip Viprakasit
- Siriraj Integrated Center of Excellence for Thalassemia (SiiCOE-T) and Division of Hematology/Oncology, Department of Pediatrics, Faculty of Medicine Siriraj Hospital, Mahidol University, 2 Wanglang Road, Siriraj, Bangkoknoi, Bangkok 10700, Thailand.
| | - Supachai Ekwattanakit
- Division of Hematology, Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, 2 Wanglang Road, Siriraj, Bangkoknoi, Bangkok 10700, Thailand
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Al-Amodi AM, Ghanem NZ, Aldakeel SA, Ibrahim Al Asoom L, Rafique Ahmed N, Almandil NB, Naserullah ZA, Al-Jarrash S, Shakil Akhtar M, AbdulAzeez S, Al-Ali AK, Borgio JF. Hemoglobin A 2 (HbA 2) has a measure of unreliability in diagnosing β-thalassemia trait (β-TT). Curr Med Res Opin 2018; 34:945-951. [PMID: 29383950 DOI: 10.1080/03007995.2018.1435520] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
INTRODUCTION Detection of β-thalassemia trait or carriers (β-TT) depends significantly on an increase in Hemoglobin A2 (HbA2) levels, which is found at low levels (<3%) in normal healthy individuals and elevated levels (≥3.5%) in β-TT individuals. The study was designed to evaluate the reliability of the diagnostic parameter HbA2 in the differentiation of β-TT and non-β-TT in Saudis. METHODS The widely used high performance liquid chromatography (Variant II Bio-Rad) was used to measure HbA2 levels in blood. Sanger sequencing was used to screen the variation in globin genes (HBB, HBD, HBA1, and HBA2). All the study subjects were divided into βTT and non-βTT (wild) categories based on the presence or absence of HBB variations and further sub-divided into false positive, true positive, false negative, and true negative, based on HbA2 values. RESULTS Out of 288 samples, 96 had HBB gene mutations. Of the 96 β-TT samples, sickle cell trait (SCT) samples (n = 58) were excluded, while the remaining (38 β-TT) were included in the detailed analysis: seven subjects with the HBB mutation had normal HbA2 (<3%), and three were borderline (3.1-3.9%). The remainder (n = 28) had an elevated HbA2 level (>4%). Based on HbA2 analysis alone, both these groups would be incorrectly diagnosed as normal. Similarly, of the 189 non-β-TT samples, 179 had normal HbA2, eight had borderline HbA2, and two had a HbA2 level above 4%. Based on HbA2 analysis alone, borderline and >4% HbA2 individuals, negative for β-TT, can be incorrectly diagnosed as carriers. CONCLUSION Given the percentage of samples falling in the HbA2 "borderline" and "normal" categories, it can be concluded that HbA2 has a measure of unreliability in the diagnosis of β-thalassemia carriers.
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Affiliation(s)
- Amani M Al-Amodi
- a Department of Genetic Research , Institute for Research and Medical Consultation (IRMC), Imam Abdulrahman Bin Faisal University , Dammam , Saudi Arabia
| | - Neda Z Ghanem
- a Department of Genetic Research , Institute for Research and Medical Consultation (IRMC), Imam Abdulrahman Bin Faisal University , Dammam , Saudi Arabia
| | - Sumayh A Aldakeel
- a Department of Genetic Research , Institute for Research and Medical Consultation (IRMC), Imam Abdulrahman Bin Faisal University , Dammam , Saudi Arabia
| | - Lubna Ibrahim Al Asoom
- b Department of Physiology, College of Medicine , Imam Abdulrahman Bin Faisal University , Dammam , Saudi Arabia
| | - Nazish Rafique Ahmed
- b Department of Physiology, College of Medicine , Imam Abdulrahman Bin Faisal University , Dammam , Saudi Arabia
| | - Noor B Almandil
- c Department of Clinical Pharmacy Research , Institute for Research and Medical Consultation (IRMC), Imam Abdulrahman Bin Faisal University , Dammam , Saudi Arabia
| | | | - Sana Al-Jarrash
- d Dammam Maternity and Child Hospital , Dammam , Saudi Arabia
| | - Mohammed Shakil Akhtar
- e Department of Biochemistry , Imam Abdulrahman Bin Faisal University , Dammam , Saudi Arabia
| | - Sayed AbdulAzeez
- a Department of Genetic Research , Institute for Research and Medical Consultation (IRMC), Imam Abdulrahman Bin Faisal University , Dammam , Saudi Arabia
| | - Amein K Al-Ali
- e Department of Biochemistry , Imam Abdulrahman Bin Faisal University , Dammam , Saudi Arabia
| | - J Francis Borgio
- a Department of Genetic Research , Institute for Research and Medical Consultation (IRMC), Imam Abdulrahman Bin Faisal University , Dammam , Saudi Arabia
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Rodrigo R, Allen A, Manampreri A, Perera L, Fisher CA, Allen S, Weatherall DJ, Premawardhena A. Haemoglobin variants, iron status and anaemia in Sri Lankan adolescents with low red cell indices: A cross sectional survey. Blood Cells Mol Dis 2018; 71:11-15. [PMID: 29409695 DOI: 10.1016/j.bcmd.2018.01.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 01/26/2018] [Accepted: 01/30/2018] [Indexed: 10/18/2022]
Abstract
Iron deficiency complicates the use of red cell indices to screen for carriers of haemoglobin variants in many populations. In a cross sectional survey of 7526 secondary school students from 25 districts of Sri Lanka, 1963 (26.0%) students had low red cell indices. Iron deficiency, identified by low serum ferritin, was the major identifiable cause occurring in 550/1806 (30.5%) students. Low red cell indices occurred in iron-replete students with alpha-thalassaemia including those with single alpha-globin gene deletions. Anaemia and low red cell indices were also common in beta-thalassaemia trait. An unexpected finding was that low red cell indices occurred in 713 iron-replete students with a normal haemoglobin genotype. It is common practice to prescribe iron supplements to individuals with low red cell indices. Since low red cell indices were a feature of all forms of α thalassaemia and also of iron deficiency, in areas where both conditions are common, such as Sri Lanka, it is imperative to differentiate between the two, to allow targeted administration of iron supplements and avoid the possible deleterious effects of increased iron availability in iron replete individuals with low red cell indices due to other causes such as α thalassaemia.
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Affiliation(s)
- Rexan Rodrigo
- Faculty of Medicine, University of Kelaniya, Sri Lanka; Thalassemia Care Unit, North Colombo Teaching Hospital, Ragama, Sri Lanka
| | - Angela Allen
- MRC Molecular Hematology Unit, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford, Oxford, UK; Centre for Tropical and Infectious Disease, Liverpool School of Tropical Medicine, Liverpool, UK
| | | | - Luxman Perera
- Thalassemia Care Unit, North Colombo Teaching Hospital, Ragama, Sri Lanka
| | - Christopher A Fisher
- MRC Molecular Hematology Unit, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford, Oxford, UK
| | - Stephen Allen
- Centre for Tropical and Infectious Disease, Liverpool School of Tropical Medicine, Liverpool, UK
| | - David J Weatherall
- MRC Molecular Hematology Unit, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford, Oxford, UK
| | - Anuja Premawardhena
- Faculty of Medicine, University of Kelaniya, Sri Lanka; Thalassemia Care Unit, North Colombo Teaching Hospital, Ragama, Sri Lanka.
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Paleari R, Ceriotti F, Harteveld CL, Strollo M, Bakker-Verweij G, ter Huurne J, Bisoen S, Mosca A. Calibration by commutable control materials is able to reduce inter-method differences of current high-performance methods for HbA 2. Clin Chim Acta 2018; 477:60-65. [DOI: 10.1016/j.cca.2017.12.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 12/01/2017] [Accepted: 12/01/2017] [Indexed: 10/18/2022]
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Gong XQ, Yang XH, Qiao LL, Cheng YJ, Zhou WJ. [Rapid detection of alpha-globin gene ααα anti-3.7 triplets with droplet digital PCR]. NAN FANG YI KE DA XUE XUE BAO = JOURNAL OF SOUTHERN MEDICAL UNIVERSITY 2017; 37:1265-1269. [PMID: 28951374 PMCID: PMC6765481 DOI: 10.3969/j.issn.1673-4254.2017.09.22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
OBJECTIVE To establish a rapid method for detection of alpha-globin gene αααanti-3.7 based on droplet digital PCR (ddPCR) technique. METHODS The differential sequence between the X1 and Y1 box of α1 gene was selected as the amplicon of the target gene with β-actin as the reference gene. The specific primers and TaqMan probes were designed, and then a quantitative method for detecting the copy number was established based on ddPCR technique. The sensitivity and accuracy of the method were evaluated by detecting 28 samples of known genotypes and 60 clinical samples. RESULTS The ddPCR-based method accurately identified the genotypes of all the 28 samples with known genotypes and detected 5 cases of αα/αααanti-3.7 from the 60 clinical samples, and the results were verified by MLPA. The sensitivity and accuracy of this method were both 100% for detecting alpha-globin gene αααanti-3.7. CONCLUSION This ddPCR-based method for detecting αααanti-3.7 triplet can be applied for population screening and in routine clinical molecular diagnosis with simple operation, rapid analysis and accurate results.
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Affiliation(s)
- Xiao-Qian Gong
- Shaoguan Maternal and Child Healthcare Hospital, Shaoguan 512026, China.E-mail:
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