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Chen M, Lv A, Zhang S, Zheng J, Zhang M, Chen L, He Q, Zhuang J, Lin N, Xu L, Huang H. First Report of Filipino β 0-Thalassemia/β-Thalassemia in a Chinese Family. Hemoglobin 2024; 48:34-38. [PMID: 38192212 DOI: 10.1080/03630269.2023.2301487] [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: 09/28/2023] [Accepted: 12/29/2023] [Indexed: 01/10/2024]
Abstract
A pregnant woman living in Fujian Province, southeastern China, presented due to a risk of having a baby with β-thalassemia major, during her second pregnancy, since she and her husband were suspected as β-thalassemia carriers and their affected daughter was a transfusion-dependent patient. Using the common α-thalassemia and β-thalassemia genotypes test, the pregnant woman was diagnosed as a β-thalassemia carrier with βIVS-2 - 654 (C→T)/βN genotype and her daughter had a homozygosity for IVS - 2 - 654 (C→T) mutation, however, no abnormalities were detected in her husband. SMRT identified a Filipino β0-deletion in her husband, and MLPA also revealed an unknown deletion in the HBB gene. Electrophoresis showed approximately 350 bp of the PCR product, and the β-Filipino genotype presented novel fracture fragments ranging from 5,112,884 to 5,231,358 bp, and lacked a 118,475 bp fragment relative to the wild-type sequence. The daughter was therefore diagnosed with the βIVS-2 - 654 (C→T)/βFilipino genotype. Prenatal diagnosis with umbilical cord blood at 27th week of gestation showed heteroztgosity for IVS - 2 - 654 (C→T) mutation in the fetus and continued pregnancy was recommended. In conclusion, we identified the Filipino β0-deletion in a Chinese family, from Fujian area, for the first time, during prenatal screening.
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Affiliation(s)
- Meihuan Chen
- Medical Genetic Diagnosis and Therapy Center, Fujian Maternity and Child Health Hospital, College of Clinical Medicine for Obstetrics & Gynecology and Pediatrics, Fujian Medical University, Fujian Provincial Key Laboratory of Prenatal Diagnosis and Birth Defect, Fuzhou, China
| | - Aixiang Lv
- Medical Genetic Diagnosis and Therapy Center, Fujian Maternity and Child Health Hospital, College of Clinical Medicine for Obstetrics & Gynecology and Pediatrics, Fujian Medical University, Fujian Provincial Key Laboratory of Prenatal Diagnosis and Birth Defect, Fuzhou, China
| | - Siwen Zhang
- Medical Genetic Diagnosis and Therapy Center, Fujian Maternity and Child Health Hospital, College of Clinical Medicine for Obstetrics & Gynecology and Pediatrics, Fujian Medical University, Fujian Provincial Key Laboratory of Prenatal Diagnosis and Birth Defect, Fuzhou, China
- The School of Medical Technology and Engineering, Fujian Medical University, Fuzhou, China
| | - Junhao Zheng
- Medical Genetic Diagnosis and Therapy Center, Fujian Maternity and Child Health Hospital, College of Clinical Medicine for Obstetrics & Gynecology and Pediatrics, Fujian Medical University, Fujian Provincial Key Laboratory of Prenatal Diagnosis and Birth Defect, Fuzhou, China
- The School of Medical Technology and Engineering, Fujian Medical University, Fuzhou, China
| | - Min Zhang
- Medical Genetic Diagnosis and Therapy Center, Fujian Maternity and Child Health Hospital, College of Clinical Medicine for Obstetrics & Gynecology and Pediatrics, Fujian Medical University, Fujian Provincial Key Laboratory of Prenatal Diagnosis and Birth Defect, Fuzhou, China
| | - Lingji Chen
- Medical Genetic Diagnosis and Therapy Center, Fujian Maternity and Child Health Hospital, College of Clinical Medicine for Obstetrics & Gynecology and Pediatrics, Fujian Medical University, Fujian Provincial Key Laboratory of Prenatal Diagnosis and Birth Defect, Fuzhou, China
| | - Qianqian He
- Medical Genetic Diagnosis and Therapy Center, Fujian Maternity and Child Health Hospital, College of Clinical Medicine for Obstetrics & Gynecology and Pediatrics, Fujian Medical University, Fujian Provincial Key Laboratory of Prenatal Diagnosis and Birth Defect, Fuzhou, China
| | - Jianlong Zhuang
- Prenatal Diagnosis Center, Quanzhou Women's and Children's Hospital, Quanzhou, China
| | - Na Lin
- Medical Genetic Diagnosis and Therapy Center, Fujian Maternity and Child Health Hospital, College of Clinical Medicine for Obstetrics & Gynecology and Pediatrics, Fujian Medical University, Fujian Provincial Key Laboratory of Prenatal Diagnosis and Birth Defect, Fuzhou, China
| | - Liangpu Xu
- Medical Genetic Diagnosis and Therapy Center, Fujian Maternity and Child Health Hospital, College of Clinical Medicine for Obstetrics & Gynecology and Pediatrics, Fujian Medical University, Fujian Provincial Key Laboratory of Prenatal Diagnosis and Birth Defect, Fuzhou, China
| | - Hailong Huang
- Medical Genetic Diagnosis and Therapy Center, Fujian Maternity and Child Health Hospital, College of Clinical Medicine for Obstetrics & Gynecology and Pediatrics, Fujian Medical University, Fujian Provincial Key Laboratory of Prenatal Diagnosis and Birth Defect, Fuzhou, China
- The School of Medical Technology and Engineering, Fujian Medical University, Fuzhou, China
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Saad HKM, Taib WRW, Ab Ghani AS, Ismail I, Al-Rawashde FA, Almajali B, Alhawamdeh M, Abd Rahman AA, Al-wajeeh AS, Al-Jamal HAN. HBB Gene Mutations and Their Pathological Impacts on HbE/β-Thalassaemia in Kuala Terengganu, Malaysia. Diagnostics (Basel) 2023; 13:diagnostics13071247. [PMID: 37046464 PMCID: PMC10147086 DOI: 10.3390/diagnostics13071247] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 02/26/2023] [Accepted: 03/23/2023] [Indexed: 03/29/2023] Open
Abstract
Background: β-thalassaemia is a disorder caused by mutations in the β-globin gene, leading to defective production of haemoglobins (Hb) and red blood cells (RBCs). It is characterised by anaemia, ineffective erythropoiesis, and iron overload. Patients with severe β-thalassaemia require lifelong blood transfusions. Haemoglobin E beta-thalassaemia (HbE/β-thalassaemia) is a severe form of β-thalassaemia in Asian countries. More than 200 alleles have been recognised in the β-globin region. Different geographical regions show different frequencies of allelic characteristics. In this study, the spectrum of β-thalassaemia (β-thal) alleles and their correlation with iron overload, in HbE/β-thalassaemia patients, β-thalassaemia trait, and HbE trait were studied. Methods: Blood samples (n = 260) were collected from 65 β-thalassaemia patients, 65 parents (fathers and/or mothers) and 130 healthy control individuals. Haematological analyses, iron profiles, and serum hepcidin levels were examined for all participants. DNA was extracted from patients’ and their parents’ blood samples, then subjected to PCR amplification. Multiplex amplification refractory mutation system PCR (MARMS-PCR) was conducted for eighteen primers to detect the mutations. Results: There was severe anaemia present in HbE/β-thalassaemia patients compared to their parents and healthy controls. The ferritin and iron levels were significantly increased in patients compared to their parents and healthy controls (p = 0.001). Two common mutations were detected among the patient group and three mutations were detected among their parents, in addition to seven novel mutations in HbE/β-thalassaemia patients (explained in results). Conclusion: Some mutations were associated with severe anaemia in β-thalassaemia patients. The detection of mutations is a prognostic marker, and could enhance the appropriate management protocols and improve the haematological and biochemical statuses of β-thalassaemia patients.
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Hariharan P, Sawant P, Sheth J, Nadkarni A. Rapid molecular identification of a rare β-globin gene deletion & its clinical implication. Indian J Med Res 2022; 155:432-437. [PMID: 36124516 PMCID: PMC9707687 DOI: 10.4103/ijmr.ijmr_4753_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Affiliation(s)
- Priya Hariharan
- Department of Haematogenetics, ICMR-National Institute of Immunohematology, K.E.M. Hospital Campus, Mumbai 400 012, Maharashtra, India
| | - Pratibha Sawant
- Department of Haematogenetics, ICMR-National Institute of Immunohematology, K.E.M. Hospital Campus, Mumbai 400 012, Maharashtra, India
| | - Jayesh Sheth
- Foundation for Research in Genetics and Endocrinology, Institute of Human Genetics, Satellite, Ahmedabad 380 015, Gujarat, India
| | - Anita Nadkarni
- Department of Haematogenetics, ICMR-National Institute of Immunohematology, K.E.M. Hospital Campus, Mumbai 400 012, Maharashtra, India,For correspondence:
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Teh LK, Elizabeth G, Lai MI, Wong L, Ismail P. Haplotype Analysis of β-Thalassaemia Major and Carriers with Filipino β°-Deletion in Sabah, Malaysia. Malays J Med Sci 2018; 25:63-71. [PMID: 30914848 PMCID: PMC6422544 DOI: 10.21315/mjms2018.25.4.6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Accepted: 05/31/2018] [Indexed: 11/16/2022] Open
Abstract
OBJECTIVE The Filipino β°-deletion has been reported as a unique mutation in East Malaysia with a severe phenotype due to the complete absence of β-globin chain synthesis. In this study, the haplotype patterns of the β-globin gene cluster were used to relate the human genetic variation to this specific β-thalassaemia mutation. METHODS The 376 study subjects included 219 β-thalassaemia major (β-TM) patients with homozygous Filipino β°-deletion and 157 carriers with heterozygous Filipino β°-deletion from 10 government hospitals in different regions of Sabah. Genomic DNA was isolated from whole blood using silica membrane based DNA purification protocol. Polymerase chain reaction restriction fragment length polymorphism analysis (PCR-RFLP) was conducted on five markers within the β-globin gene cluster to construct the haplotype patterns. RESULTS Four haplotypes (Haplotype I-IV) were identified with Haplotype I as the predominant haplotype with the highest frequency of 0.98, followed by Haplotype II, III and Haplotype IV with 0.02. Haplotype I was strongly linked with the Filipino β°-deletion among the indigenous population. CONCLUSION Haplotype I as the predominant haplotype suggests the patients with the Filipino β°-deletion in Sabah have a similar origin.
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Affiliation(s)
- Lai Kuan Teh
- Department of Biomedical Science, Faculty of Sciences, Universiti Tunku Abdul Rahman, 39100 Kampar, Perak, Malaysia
- Department of Pathology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
| | - George Elizabeth
- Department of Pathology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
- Assunta Hospital, Jalan Templer, Petaling Jaya, Selangor, Malaysia
| | - Mei I Lai
- Department of Pathology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
| | - Lily Wong
- Department of Medicine, Hospital Queen Elizabeth, 88586 Kota Kinabalu, Sabah, Malaysia
| | - Patimah Ismail
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
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A commentary on molecular basis of transfusion dependent beta-thalassemia major patients in Sabah. J Hum Genet 2014; 59:173. [DOI: 10.1038/jhg.2013.142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Molecular basis of transfusion dependent beta-thalassemia major patients in Sabah. J Hum Genet 2013; 59:119-23. [PMID: 24369358 DOI: 10.1038/jhg.2013.131] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Revised: 11/28/2013] [Accepted: 11/29/2013] [Indexed: 11/08/2022]
Abstract
Beta-thalassemia is one of the most prevalent inherited diseases and a public health problem in Malaysia. Malaysia is geographically divided into West and East Malaysia. In Sabah, a state in East Malaysia, there are over 1000 estimated cases of β-thalassemia major patients. Accurate population frequency data of the molecular basis of β-thalassemia major are needed for planning its control in the high-risk population of Sabah. Characterization of β-globin gene defects was done in 252 transfusion dependent β-thalassemia patients incorporating few PCR techniques. The study demonstrates that β-thalassemia mutations inherited are ethnically dependent. It is important to note that 86.9% of transfusion-dependent β-thalassemia major patients in Sabah were of the indigenous population and homozygous for a single mutation. The Filipino β(0)-deletion was a unique mutation found in the indigenous population of Sabah. Mutations common in West Malaysia were found in 11 (4.3%) patients. Four rare mutations (Hb Monroe, CD 8/9, CD 123/124/125 and IVS I-2) were also found. This study is informative on the population genetics of β-thalassemia major in Sabah.
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Cui J, Azimi M, Baysdorfer C, Vichinsky EP, Hoppe CC. Application of multiplex ligation-dependent probe amplification to screen for β-globin cluster deletions: detection of two novel deletions in a multi ethnic population. Hemoglobin 2013; 37:241-56. [PMID: 23577918 DOI: 10.3109/03630269.2013.782461] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Hereditary persistence of fetal hemoglobin (HPFH) and δβ-thalassemia (δβ-thal) are heterogeneous disorders caused by deletions within the β-globin gene cluster. When combined with other β-thal mutations or structural hemoglobin (Hb) variants, these deletions give rise to clinical phenotypes ranging from an asymptomatic condition to β-thal major (β-TM). Overlap in hematological parameters and variability in expression of Hbs A2 and F make molecular testing necessary to distinguish clinically relevant deletions. Multiplex ligation-dependent probe amplification (MLPA) was used to screen for β-globin gene cluster deletions in 49 unresolved samples referred for a suspected β-thal anomaly. The 1.39 kb Black β(0), 3.5 kb Thai β(0), 118 kb Filipino β(0), 11.8 kb Black (δβ)(0), 13.4 kb Sicilian (δβ)(0), 35.8 kb Black ((A)γδβ)0, Hb Lepore-Boston-Washington (Hb LBW) and HPFH-2 deletions, and two novel deletions, a 61.7 kb Pakistani β(0) deletion and an ((A)γδβ)(0) deletion, were identified in 15 cases. Detection of both known and unknown deletional Hb disorders provides for appropriate clinical management and genetic counseling.
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Affiliation(s)
- Jialing Cui
- Hemoglobinopathy Reference Laboratory, Children's Hospital & Research Center Oakland, Oakland, California, USA
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HbA2 levels in β-thalassaemia carriers with the Filipino β0-deletion: are the levels higher than what is found with non-deletional forms of β0-thalassaemia? Pathology 2012; 45:62-5. [PMID: 23222244 DOI: 10.1097/pat.0b013e32835af7c1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
AIMS Classical carriers of β-thalassaemia are identified by a raised HbA2 level. Earlier studies indicated that the Filipino β-deletion has high raised HbA2 levels. The introduction of automated high performance liquid chromatography (HPLC) for thalassaemia screening is an important advance in technology for haematology laboratories. The BioRad Variant II Hb analyser is a common instrument used to quantify HbA2 levels in thalassaemia screening. This study aimed to determine HbA2 levels in carriers of Filipino β-mutation using the BioRad Variant II Hb analyser. METHODS The Filipino β-deletion was identified using gap-polymerase chain reaction (PCR) in the parents of transfusion dependent β-thalassaemia patients who were homozygous for the Filipino β-deletion in the indigenous population of Sabah, Malaysia. Hb subtypes were quantified on the BioRad Variant II Hb analyser. Concurrent α-thalassaemia was identified by multiplex gap-PCR for deletions and amplification refractory mutation system (ARMS)-PCR for non-deletional mutations. RESULTS The mean HbA2 level for Filipino β-thalassaemia trait was 5.9 ± 0.47 and with coinheritance of α-thalassaemia was 6.3 ± 0.44 (-α heterozygous) and 6.7 ± 0.36 (-α homozygous). The HbA2 levels were all >4% in keeping with the findings of classical β-thalassaemia trait and significantly higher than levels seen in non-deletional forms of β-thalassaemia. CONCLUSION The HbA2 level measured on the BioRad Variant II Hb analyser was lower than the level in the first description of the Filipino β-thalassaemia. β-thalassaemia trait with coinheritance of α-thalassaemia (-α) is associated with significantly higher HbA2 level.
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Tritipsombut J, Phylipsen M, Viprakasit V, Chalaow N, Sanchaisuriya K, Giordano PC, Fucharoen S, Harteveld CL. A Single-Tube Multiplex Gap-Polymerase Chain Reaction for the Detection of Eight β-Globin Gene Cluster Deletions Common in Southeast Asia. Hemoglobin 2012. [DOI: 10.3109/03630269.2012.747441] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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11
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Yamsri S, Sanchaisuriya K, Fucharoen G, Fucharoen S. Genetic origin and interaction of the Filipino β⁰-thalassemia with Hb E and α-thalassemia in a Thai family. Transl Res 2012; 159:473-6. [PMID: 22633098 DOI: 10.1016/j.trsl.2011.10.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2011] [Revised: 10/19/2011] [Accepted: 10/25/2011] [Indexed: 11/20/2022]
Abstract
We describe hematologic and molecular characteristics of a hitherto undescribed interaction between the Filipino deletional β⁰-thalassemia with Hb E and α-thalassemia in a Thai family. This study was conducted during the prenatal screening of a pregnant Thai woman and her family members. A prenatal diagnosis was performed at her second pregnancy by amniocentesis. Laboratory investigations identified that the pregnant woman was Hb E heterozygote with α⁺-thalassemia, whereas her husband was a double heterozygote for the Filipino deletional β⁰-thalassemia and α⁺-thalassemia. Their affected son was a patient with a previously undescribed condition of Hb E-β⁰-thalassemia with α⁺-thalassemia. Both a combined gap-polymerase chain reaction (PCR) and allele-specific PCR were used successfully in the prenatal diagnosis, which identified an affected fetus with Hb E-β⁰-thalassemia without α⁺-thalassemia. Beta globin gene haplotype analysis indicated the same origin of this Filipino β⁰-thalassemia in Asian populations.
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Affiliation(s)
- Supawadee Yamsri
- Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand
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High prevalence of alpha- and beta-thalassemia in the Kadazandusuns in East Malaysia: challenges in providing effective health care for an indigenous group. J Biomed Biotechnol 2010; 2010. [PMID: 20871816 PMCID: PMC2943116 DOI: 10.1155/2010/706872] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2010] [Revised: 06/30/2010] [Accepted: 07/20/2010] [Indexed: 11/18/2022] Open
Abstract
Thalassemia can lead to severe transfusion-dependent anemia, and it is the most common genetic disorder in Malaysia. This paper aims to determine the prevalence of thalassemia in the Kadazandusuns, the largest indigenous group in Sabah, East Malaysia. α- and β-thalassemia were confirmed in 33.6% and 12.8%, of the individuals studied respectively. The high prevalence of α- and β-thalassemia in the Kadazandusuns indicates that thalassemia screening, genetic counseling, and prenatal diagnosis should be included as part of their healthcare system. This preliminary paper serves as a baseline for further investigations into the health and genetic defects of the major indigenous population in Sabah, East Malaysia.
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Joly P, Lacan P, Garcia C, Couprie N, Francina A. Identification and molecular characterization of four new large deletions in the β-globin gene cluster. Blood Cells Mol Dis 2009; 43:53-7. [DOI: 10.1016/j.bcmd.2009.01.017] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2008] [Revised: 01/20/2009] [Accepted: 01/23/2009] [Indexed: 11/25/2022]
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Setianingsih I, Williamson R, Daud D, Harahap A, Marzuki S, Forrest S. Phenotypic variability of Filipino beta(o)-thalassemia/HbE patients in Indonesia. Am J Hematol 1999; 62:7-12. [PMID: 10467270 DOI: 10.1002/(sici)1096-8652(199909)62:1<7::aid-ajh2>3.0.co;2-s] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Three Indonesian patients with identical genotypes, each compound heterozygotes for Filipino beta(o)-thalassemia/HbE, expressed different clinical severities. One patient has mild disease and is transfusion independent, while the other two are severely affected and transfusion dependent. The size of the Filipino beta(o)-globin gene deletion was confirmed to be 45 kb, resolving conflicting values given in the literature. Neither ameliorating genetic factors such as alpha-globin gene deletions or the XmnI restriction site polymorphism at position -158 upstream of the (G)gamma-globin gene, nor differences in beta-globin gene haplotype, explain the phenotypic variation. These observations have implications for the development of antenatal diagnosis in Indonesia, as at present it is not possible to give an accurate prediction of severity of phenotype for this common genotype.
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Affiliation(s)
- I Setianingsih
- The Murdoch Institute, Royal Children's Hospital, Flemington Road, Parkville, Melbourne, Australia.
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Abstract
A complete spectrum of genetic lesions affecting the beta-globin gene giving rise to a complete spectrum of phenotypic severity is described. Although most of the molecular lesions involve the structural beta gene directly, some down regulate the gene through in-cis effects at a distance while trans-acting factors are implicated in a few cases. The remarkable phenotypic diversity can be related ultimately to the degree of alpha-globin-beta-globin chain imbalance and arises from variability of mutations affecting the beta gene itself and from interactions with other genetic loci, such as the alpha- and gamma-globin genes. The presence of other interacting loci is implicated by their interactions in increasing gamma gene expression or by an increased proteolytic capacity of the erythroid precursors. It is hoped that observations from the genotype-phenotype relationship might form the basis for a comprehensive diagnostic database that will be useful not only for genetic counselling and prenatal diagnosis but also for providing prognostic information for decision making in bone marrow transplantation and gene therapy programmes in the future. However, it is clear from recent analyses that, apart from the two categories of triplicated alpha genes with heterozygous beta-thalassaemia and inheritance of mild beta(+)-thalassaemia alleles, it is still not possible to predict consistently phenotype from alpha and beta genotypes alone owing to the influence of the other modulating factors, some implicated (such as inheritance of hereditary persistence of fetal haemoglobin) and others as yet unidentified.
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Affiliation(s)
- S L Thein
- MRC Molecular Haematology Unit, John Radcliffe Hospital, Headington, Oxford, UK
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16
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Affiliation(s)
- T H Huisman
- Editorial Office, HEMOGLOBIN, Medical College of Georgia, Augusta 30912-2100, USA
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Dimovski AJ, Baysal E, Efremov DG, Prior JF, Raven JL, Efremov GD, Huisman TH. A large beta-thalassemia deletion in a family of Indonesian-Malay descent. Hemoglobin 1996; 20:377-92. [PMID: 8936464 DOI: 10.3109/03630269609005842] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The partial molecular characterization of a large deletion present in two members of an Indonesian-Malay family with beta-thalassemia trait is described. Polymerase chain reaction and sequencing analyses of the breakpoint identified a sequence which has previously been described in patients with the 45 kb Filipino beta 0-thalassemia deletion, i.e. a 5' breakpoint at position -4279 nucleotides 5' from the Cap site of the beta-globin gene. The 3' breakpoint is located in an L1 family of repetitive sequences at an unknown distance from the beta-globin gene. The hematological and hemoglobin data of the patients with this beta 0-thalassemia deletion further supports the concept that the unusually high Hb A2 levels are unique to deletions removing the 5' beta-globin gene region, and points to the importance of the 3' junction sequences for the regulation of Hb F levels in patients with deletional defects of the beta-globin gene cluster.
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Affiliation(s)
- A J Dimovski
- Department of Biochemistry and Molecular Biology Medical College of Georgia, Augusta 30912-2100, USA
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18
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Affiliation(s)
- E Baysal
- Department of Biochemistry and Molecular Biology Medical College of Georgia, Augusta 30912-2100, USA
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19
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Waye JS, Eng B, Hunt JA, Chui DH. Filipino beta-thalassemia due to a large deletion: identification of the deletion endpoints and polymerase chain reaction (PCR)-based diagnosis. Hum Genet 1994; 94:530-2. [PMID: 7959690 DOI: 10.1007/bf00211021] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The gene frequency of beta-thalassemia among Filipinos is estimated to be 0.02, although little is known about the mutations involved. Recently, an extensive beta-thalassemia deletion was reported in several unrelated individuals of Filipino descent. The deletion begins approximately 4 kb upstream of the beta-globin gene, and extends 3' beyond the beta-globin gene. In this report, we identify the 5' and 3' deletion endpoints and present a polymerase chain reaction (PCR) strategy for rapid DNA diagnosis of the Filipino beta-thalassemia deletion.
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Affiliation(s)
- J S Waye
- Provincial Hemoglobinopathy DNA Diagnostic Laboratory, McMaster University Medical Centre, Hamilton, Ontario, Canada
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