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Diamantidis MD, Karanikola RA, Polyzoudi C, Delicou S, Manafas A, Savera H, Xydaki A, Kotsiafti A, Tsangalas E, Ikonomou G, Mani E, Ntoulas K, Alexiou E, Argyrakouli I, Koskinas J, Fotiou P. Clinical significance of mutational variants in beta and alpha genes in patients with hemoglobinopathies from two large Greek centers: a complex interplay between genotype and phenotype. J Mol Med (Berl) 2023; 101:1073-1082. [PMID: 37420139 DOI: 10.1007/s00109-023-02342-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 06/15/2023] [Accepted: 06/19/2023] [Indexed: 07/09/2023]
Abstract
Hemoglobinopathies affect patients in the wider Mediterranean area consisting of 4 distinct subgroups: beta thalassemia major (TM), beta thalassemia intermedia (TI), sickle cell disease (SCD) and hemoglobin H disease (alpha thalassemia). The clinical spectrum varies from mild to severe. Complex interactions between genes and environmental factors form the clinical manifestations. There is an unmet need to clarify these multifactorial mechanisms. This is the first Greek study describing mutational alleles (HBB and HBA1/HBA2 gene variants) in 217 patients with hemoglobinopathies of two large centers in Greece (Larissa and Athens) and associating particular genotypes or gene variants with clinical manifestations (transfusion frequency, complications). Thus, the complex interplay between corresponding genotypes and phenotypes was investigated. Our results are in accordance with previous national studies with limited variations, due to regional prevalence of specific gene variants, as expected. It is also a description of the prevalence of hemoglobinopathies in the Greek population. The type and prevalence of beta and alpha globin gene variants differ significantly among countries. We also confirm the well-known observation of many studies that in our beta thalassemic or SCD patients, co-inheritance of variants in the alpha globin genes, leading to absence or reduction of alpha globin synthesis were associated with milder clinical course, whereas the inheritance of additional alpha genes (triplication) led to a more severe clinical phenotype. In cases in whom the genotype and phenotype did not correlate, factors like the function or modification of possible regulatory genes or additional nutritional-environmental effects should be investigated. KEY MESSAGES: • This is the first Greek study, fully molecularly defining the beta and alpha mutational alleles in 217 patients with hemoglobinopathies of two large centers in Greece and correlating particular genotypes or gene variants with clinical manifestations (transfusion frequency, complications). • In the beta thalassemic or SCD patients of our cohort, co-inheritance of variants in the alpha globin genes, leading to absence or reduction of alpha globin synthesis were associated with milder clinical course (confirmation of a well-known previous observation). • The inheritance of additional alpha genes (triplication) led to a more severe clinical phenotype (confirmation of a well known previous observation). • The function or modification of possible regulatory genes should be investigated in cases in whom the genotype and phenotype did not correlate.
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Affiliation(s)
- Michael D Diamantidis
- Thalassemia and Sickle Cell Disease Unit, Department of Hematology, First Department of Internal Medicine, General Hospital of Larissa, Tsakalov St. 1, 41 221, Larissa, Greece.
| | - Rebecca-Anastasia Karanikola
- Thalassemia and Sickle Cell Disease Unit, Department of Hematology, First Department of Internal Medicine, General Hospital of Larissa, Tsakalov St. 1, 41 221, Larissa, Greece
| | - Chrysoula Polyzoudi
- Thalassemia and Sickle Cell Disease Unit, Department of Hematology, First Department of Internal Medicine, General Hospital of Larissa, Tsakalov St. 1, 41 221, Larissa, Greece
| | - Sophia Delicou
- Thalassemia and Sickle Cell Disease Unit, Hippokration General Hospital of Athens, Athens, Greece
| | - Achilles Manafas
- Thalassemia and Sickle Cell Disease Unit, Department of Hematology, First Department of Internal Medicine, General Hospital of Larissa, Tsakalov St. 1, 41 221, Larissa, Greece
| | - Helen Savera
- Thalassemia and Sickle Cell Disease Unit, Department of Hematology, First Department of Internal Medicine, General Hospital of Larissa, Tsakalov St. 1, 41 221, Larissa, Greece
| | - Aikaterini Xydaki
- Thalassemia and Sickle Cell Disease Unit, Hippokration General Hospital of Athens, Athens, Greece
| | - Angeliki Kotsiafti
- Thalassemia and Sickle Cell Disease Unit, Hippokration General Hospital of Athens, Athens, Greece
| | - Evangelos Tsangalas
- Thalassemia and Sickle Cell Disease Unit, Department of Hematology, First Department of Internal Medicine, General Hospital of Larissa, Tsakalov St. 1, 41 221, Larissa, Greece
| | - Georgia Ikonomou
- Thalassemia Prevention Unit, General Hospital of Larissa, Larissa, Greece
| | - Eirini Mani
- Thalassemia Prevention Unit, General Hospital of Larissa, Larissa, Greece
| | - Konstantinos Ntoulas
- Thalassemia and Sickle Cell Disease Unit, Department of Hematology, First Department of Internal Medicine, General Hospital of Larissa, Tsakalov St. 1, 41 221, Larissa, Greece
| | - Evangelos Alexiou
- Thalassemia and Sickle Cell Disease Unit, Department of Hematology, First Department of Internal Medicine, General Hospital of Larissa, Tsakalov St. 1, 41 221, Larissa, Greece
| | - Ioanna Argyrakouli
- Thalassemia and Sickle Cell Disease Unit, Department of Hematology, First Department of Internal Medicine, General Hospital of Larissa, Tsakalov St. 1, 41 221, Larissa, Greece
| | - John Koskinas
- Thalassemia and Sickle Cell Disease Unit, Hippokration General Hospital of Athens, Athens, Greece
| | - Paraskevi Fotiou
- Thalassemia and Sickle Cell Disease Unit, Department of Hematology, First Department of Internal Medicine, General Hospital of Larissa, Tsakalov St. 1, 41 221, Larissa, Greece
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Liang HF, Liang WM, Xie WG, Lin F, Liu LL, Li LJ, Ge YY, Lu M, Liao YW, Zeng GK, Yao JX, Situ JW, Yang LY. The gene spectrum of thalassemia in Yangjiang of western Guangdong Province. Front Genet 2023; 14:1126099. [PMID: 36861132 PMCID: PMC9968962 DOI: 10.3389/fgene.2023.1126099] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Accepted: 01/18/2023] [Indexed: 02/15/2023] Open
Abstract
Background: Thalassemia presents a higher incidence in southern China. The objective of this study is to analyze the genotype distribution of thalassemia in Yangjiang, a western city of Guangdong Province in China. Methods: The genotypes of suspected cases with thalassemia were tested by PCR and reverse dot blot (RDB). Unidentified rare thalassemia genotypes of the samples were further ascertained by PCR and direct DNA sequencing. Results: Among 22467 suspected cases with thalassemia, 7658 cases were found with thalassemia genotypes using our PCR-RDB kit. Among these 7658 cases, 5313 cases were found with α-thalassemia (α-thal) alone, --SEA/αα was the most common genotype, accounting for 61.75% of α-thal genotypes, and the following mutations were found: α3.7/αα, -α4.2/αα, αCSα/αα, αWSα/αα, and αQSα/αα. A total of 2032 cases were found with β-thalassemia (β-thal) alone. βCD41-42/βN, βIVS-II-654/βN, and β-28/βN accounted for 80.9% of all β-thal genotypes, and the following genotypes were found: βCD17/βN, βCD71-72/βN, and βE/βN. Compound heterozygotes of β-thal and β-thalassemia homozygotes were identified in 11 and five cases, respectively, in this study. α-thal combined with β-thal was identified in 313 cases, showing 57 genotype combinations of the coincidence of both Hb disorders; one extreme patient had a genotype of --SEA/αWSα and βCD41-42/β-28. In addition, four rare α-mutations (--THAI, HKαα, Hb Q-Thailand, and CD31 AGG>AAG) and six rare β-mutations (CD39 CAG>TAG, IVS-Ⅱ-2 (-T), -90(C>T), Chinese Gγ+(Aγδβ)0, CD104 (-G), and CD19 A>G) were also found in this study population. Conclusion: This study provided detailed genotypes of thalassemia in Yangjiang of western Guangdong Province in China and reflected the complexity of genotypes in this high-prevalence region, and this would be valuable for diagnosis and counseling for thalassemia in this area.
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Affiliation(s)
- Hong-Feng Liang
- Precision Medical Lab Center, People’s Hospital of Yangjiang, Yangjiang, Guangdong, China
| | - Wei-Min Liang
- Medical Laboratory, Women and Children Hospital of Yangjiang, Yangjiang, Guangdong, China
| | - Wen-Guang Xie
- Medical Laboratory, Women and Children Hospital of Yangjiang, Yangjiang, Guangdong, China
| | - Fen Lin
- Precision Medical Lab Center, Chaozhou Central Hospital Affiliated to Southern Medical University, Chaozhou, Guangdong, China
| | - Li-Li Liu
- Precision Medical Lab Center, People’s Hospital of Yangjiang, Yangjiang, Guangdong, China
| | - Lie-Jun Li
- Guangdong Hybribio Limited Corporation, Chaozhou, Guangdong, China
| | - Yi-Yuan Ge
- Guangdong Hybribio Limited Corporation, Chaozhou, Guangdong, China
| | - Min Lu
- Guangdong Hybribio Limited Corporation, Chaozhou, Guangdong, China
| | - Yu-Wei Liao
- Precision Medical Lab Center, People’s Hospital of Yangjiang, Yangjiang, Guangdong, China
| | - Guang-Kuan Zeng
- Precision Medical Lab Center, People’s Hospital of Yangjiang, Yangjiang, Guangdong, China
| | - Jin-Xiu Yao
- Laboratory Medical Center, People’s Hospital of Yangjiang, Yangjiang, Guangdong, China
| | - Jing-Wei Situ
- Laboratory Medical Center, People’s Hospital of Yangjiang, Yangjiang, Guangdong, China
| | - Li-Ye Yang
- Precision Medical Lab Center, People’s Hospital of Yangjiang, Yangjiang, Guangdong, China,*Correspondence: Li-Ye Yang,
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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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Rizo-de-la-Torre LC, Ibarra B, Sánchez-López JY, Magaña-Torres MT, Rentería-López VM, Perea-Díaz FJ. Three novel HBB mutations, c.-140C>G (-90 C>G), c.237_256delGGACAACCTCAAGGGCACCT (FS Cd 78/85 -20 bp), and c.315+2T>G (IVS2:2 T>G). Update of the mutational spectrum of β-Thalassemia in Mexican mestizo patients. Int J Lab Hematol 2017; 39:539-545. [PMID: 28603845 DOI: 10.1111/ijlh.12692] [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: 09/27/2016] [Accepted: 03/24/2017] [Indexed: 11/28/2022]
Abstract
INTRODUCTION Beta-thalassemia (β-thal) is frequent in Mexican patients with microcytosis and hypochromia. We report three novel mutations and analyze the actual mutational spectrum in Mexican population. METHODS One hundred and forty-nine β-thal Mexican mestizo patients were studied (154 alleles). ARMS-PCR was performed to identify Cd39C>T, IVS1:1G>A, IVS1:110G>A, -28A>C, initiation codonA>G and IVS1:5G>A mutations, and gap-PCR for δβ-thal Spanish type. DNA sequencing of HBB gene was carried out in negative samples for the initial screening. RESULTS Fifteen different HBB gene mutations were observed in 148 alleles; three of them are novel: -90C>G, 20 bp deletion (at codons 78/85), and IVS2:2T>G; the mutation IVS1:6T>C that was observed for first time in our population; and eleven previously described mutations. Six alleles showed normal HBB sequence. To date, a total of 21 different mutations have been observed in Mexican patients; the four most frequent mutations are of Mediterranean origin: Cd39C>T (37.2%), IVS1:1G>A (17.3%), IVS1:110G>A (13.9%), and δβ-thal Spanish type (9.0%), which represent 77.4% of the total studied alleles. CONCLUSION Considering the novel mutations -90C>G, -20 bp Cd78/85, IVS2:2T>G and the first observation of IVS1:6T>C, the molecular spectrum of β-thal in Mexicans comprises 21 different mutations, confirming the high allelic heterogeneity in Mexicans.
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Affiliation(s)
- L C Rizo-de-la-Torre
- Doctorado en Genética Humana, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Guadalajara, Jalisco, México.,División de Genética, Centro de Investigación Biomédica de Occidente, Instituto Mexicano del Seguro Social, Guadalajara, Jalisco, México
| | - B Ibarra
- Doctorado en Genética Humana, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Guadalajara, Jalisco, México
| | - J Y Sánchez-López
- División de Genética, Centro de Investigación Biomédica de Occidente, Instituto Mexicano del Seguro Social, Guadalajara, Jalisco, México
| | - M T Magaña-Torres
- División de Genética, Centro de Investigación Biomédica de Occidente, Instituto Mexicano del Seguro Social, Guadalajara, Jalisco, México
| | - V M Rentería-López
- División de Genética, Centro de Investigación Biomédica de Occidente, Instituto Mexicano del Seguro Social, Guadalajara, Jalisco, México
| | - F J Perea-Díaz
- División de Genética, Centro de Investigación Biomédica de Occidente, Instituto Mexicano del Seguro Social, Guadalajara, Jalisco, México
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Martyn GE, Quinlan KGR, Crossley M. The regulation of human globin promoters by CCAAT box elements and the recruitment of NF-Y. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2016; 1860:525-536. [PMID: 27718361 DOI: 10.1016/j.bbagrm.2016.10.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 09/30/2016] [Accepted: 10/03/2016] [Indexed: 01/01/2023]
Abstract
CCAAT boxes are motifs found within the proximal promoter of many genes, including the human globin genes. The highly conserved nature of CCAAT box motifs within the promoter region of both α-like and β-like globin genes emphasises the functional importance of the CCAAT sequence in globin gene regulation. Mutations within the β-globin CCAAT box result in β-thalassaemia, while mutations within the distal γ-globin CCAAT box cause the Hereditary Persistence of Foetal Haemoglobin, a benign condition which results in continued γ-globin expression during adult life. Understanding the transcriptional regulation of the globin genes is of particular interest, as reactivating the foetal γ-globin gene alleviates the symptoms of β-thalassaemia and sickle cell anaemia. NF-Y is considered to be the primary activating transcription factor which binds to globin CCAAT box motifs. Here we review recruitment of NF-Y to globin CCAAT boxes and the role NF-Y plays in regulating globin gene expression. This article is part of a Special Issue entitled: Nuclear Factor Y in Development and Disease, edited by Prof. Roberto Mantovani.
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Affiliation(s)
- Gabriella E Martyn
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, NSW 2052, Australia
| | - Kate G R Quinlan
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, NSW 2052, Australia
| | - Merlin Crossley
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, NSW 2052, Australia.
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Prajantasen T, Teawtrakul N, Fucharoen G, Fucharoen S. Molecular Characterization of a β-Thalassemia Intermedia Patient Presenting Inferior Vena Cava Thrombosis: Interaction of the β-Globin Erythroid Krüppel-Like Factor Binding Site Mutation with Hb E and α+-Thalassemia. Hemoglobin 2014; 38:451-3. [DOI: 10.3109/03630269.2014.974608] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Achoubi N, Asghar M, Saraswathy KN, Murry B. Prevalence of β-Thalassemia and hemoglobin E in two migrant populations of Manipur, North East India. Genet Test Mol Biomarkers 2013; 16:1195-200. [PMID: 23057593 DOI: 10.1089/gtmb.2011.0373] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Hemoglobinopathies are a group of inherited single-gene disorders found commonly in the Mediterranean region, Middle East, Indian subcontinent, Burma, and South East Asia. As many as 229 mutation variants of β-thalassemia are reported in the world, many community/region-specific mutations. Very little on thalassemia has been reported in Manipur, a North Eastern Indian state. Thus, a community genetic approach through population screening can be applied to the people of Manipur and a total of 602 blood samples from unrelated Meitei Brahmins (n=300) and Meitei Muslims (n=302) were screened for abnormal hemoglobins by Naked Eye Single Tube Red Cell Osmotic Fragility Test (NESTROFT). HBA(2) level was estimated by using high-performance liquid chromatography and molecular analysis was done by using PCR. Sequencing was also carried out to confirm the mutations. High frequencies of NESTROFT positive (10%) and NESTROFT doubtful (11%) cases were found among the Meitei Brahmins in comparison to the Meitei Muslims [NESTROFT positive (3.31%) and NESTROFT doubtful (1.33%)]. The allele frequency of HB*E was 0.022 and 0.012 among the Meitei Brahmin and Meitei Muslim, respectively. Sequencing of the β-globin gene confirmed a very rare β-thalassemia [-90 C→T (0.33%)] among the Meitei Brahmins of Manipur. This mutation with hemoglobin E in one of the present population hints the presence of the Mongoloid stock among them, possibly from China. There is a need for further studies on other populations of Manipur and the neighboring North East Indian states using such genetic markers.
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Affiliation(s)
- Nongthombam Achoubi
- Molecular Anthropology Laboratory, Department of Anthropology, University of Delhi, Delhi, India
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López-Escribano H, Parera MM, Guix P, Serra JM, Gutierrez A, Balsells D, Oliva-Berini E, Castro JA, Ramon MM, Picornell A. Balearic archipelago: three islands, three beta-thalassemia population patterns. Clin Genet 2012; 83:175-80. [DOI: 10.1111/j.1399-0004.2012.01864.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Moatter T, Kausar T, Aban M, Ghani S, Pal JA. Prenatal screening for β-thalassemia major reveals new and rare mutations in the Pakistani population. Int J Hematol 2012; 95:394-8. [PMID: 22392582 DOI: 10.1007/s12185-012-1036-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Revised: 02/20/2012] [Accepted: 02/23/2012] [Indexed: 11/24/2022]
Abstract
β-Thalassemia is the most common genetic disorder in Pakistan, where more than 6000 affected children are born annually, and the carrier population is around 10 million. The objective was to study β-globin gene mutations in chorionic villous biopsy samples. Prenatal screening of 383 pregnant women between 2003 and 2010 was carried out using a panel of 13 mutation primers and amplification refractory mutations system (ARMS)-PCR. In addition, DNA sequencing was used to confirm uncharacterized mutations and in some cases fetal disease status was confirmed by linkage analysis. Families enrolled in this study represented major ethnic groups in Pakistan. Of the 13 mutations tested, three mutations accounted 71% of the total, including IVS1-5(G-C)[HBB:c.92+5G>C], codon 8/9(+G) [HBB:c.27_28insG] and del 619[NG_000007.3:g71609-72227del619]. Mutations in four uncharacterized samples were later confirmed by DNA sequencing as -88(C-T)[HBB:c.-138C>G], -90(C-T)[HBB:c.-140C>T] and codon 59(+T)[HBB:c.178_179insT]. To our knowledge, this is the first report of these mutations in Pakistan. Moreover, 19.2% fetal samples were normal and 52.3% heterozygous, whereas 26.4% were affected with thalassemia major. IVS1-5:IVS1-5 was the most common genotype in fetal samples. Prenatal diagnosis of β-thalassemia using ARMS PCR is an efficient approach for reducing the burden of this disease in Pakistan. In addition, rare mutations reported in this study should be incorporated in the diagnostic strategy.
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Affiliation(s)
- Tariq Moatter
- Department of Pathology and Microbiology, Aga Khan University, Stadium Road, Karachi 74800, Pakistan.
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Lemsaddek W, Picanço I, Seuanes F, Nogueira P, Mahmal L, Benchekroun S, Khattab M, Osório-Almeida L. The β‐Thalassemia Mutation/Haplotype Distribution in the Moroccan Population. Hemoglobin 2009; 28:25-37. [PMID: 15008262 DOI: 10.1081/hem-120028884] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The present study compiles the results of our own research and of a prior study on beta-thalassemia (thal) in Morocco, comprising a total of 187 beta-thalassemic chromosomes. Six major mutations: (beta0) codon 39 (C --> T), (beta+) IVS-I-6 (T --> C), (beta0) frameshift codon (FSC) 6 (-A), (beta0) FSC 8 (-AA), (beta0) IVS-I-1 (G --> A) and (beta+) -29 (A --> G) account for 75.7% of the independent chromosomes studied. A regional predominance was observed (Gharb and West regions) for the (beta+) IVS-I-6 (T --> C) mutation. Despite an observed heterogeneity of molecular anomalies, a direct method of diagnosis of the prevalent mutations is feasible in this population. The distributions of mutations and haplotypes are in conformity with the geographical location of Morocco and the historical links with both the Mediterranean communities that have successively interspersed with the Berbers, the Phoenicians, the Carthaginians, the Romans, the Arabs, the population of the Iberian Peninsula and, to a lesser degree, the Vandals and the Byzantines and permanently, with the Sub-Saharan Africans. In the adult population, the levels of fetal hemoglobin (Hb) in heterozygotes vary from trace quantities to 2.38 g/dL of total Hb. With the exception of the (beta0) codon 39 (C --> T) nonsense mutation, no statistically significant correlation was found, neither between mutation and Hb F levels, nor gender and Hb F levels in heterozygotes. The genetic markers for Hb F increase, located within cis active sites such as the XmnI site at -158 bp of the Ggamma-globin gene and the AT(X)T(Y) repeat region at -540 bp of the beta-globin gene, were assessed. The polymorphism XmnI shows linkage disequilibrium with haplotypes III, IV and IX, as previously observed in the Algerian, Sicilian and Portuguese beta-thal populations. Contrary to what has previously been reported for a population of beta-thal carriers of European descent, this sample does not show a statistically significant correlation between Hb F levels and the presence of the genetic markers XmnI restriction site at -158 bp of the Ggamma-globin gene and AT(X)T(Y) alleles at 5' of the beta-globin gene.
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Affiliation(s)
- Wafaâ Lemsaddek
- Laboratório de Genética Molecular, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
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Boudrahem-Addour N, Zidani N, Carion N, Labie D, Belhani M, Beldjord C. Molecular heterogeneity of beta-thalassemia in Algeria: how to face up to a major health problem. Hemoglobin 2009; 33:24-36. [PMID: 19205970 DOI: 10.1080/03630260802626061] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
This study concerns the molecular characterization of beta-thalassemia (beta-thal) alleles in 210 chromosomes. In the studied population, mutations were detected in 98% of the beta-thalassemic chromosomes. Twenty-one molecular defects have been found, where the five dominant mutations, IVS-I-110 (G>A), nonsense mutation at codon 39 (C>T), the frameshift codon (FSC) 6 (-A), IVS-I-1 (G>A), and IVS-I-6 (T>C), account for 80% of the independent chromosomes. Among the remaining alleles, 16 different mutations were identified, half of them being described for the first time in Algeria. These include the -101 (C>T) and the -90 (C>T) mutations in the distal and proximal promoter elements, respectively, the FSC 8 (-AA), IVS-I-5 (G>T), IVS-I-128 (T>G), FSC 47 (+A), IVS-II-1 (G>A), and the substitution in the polyadenylation signal (poly A) site AATAAA>AATGAA. Haplotype analyses on rare variants were performed. The possible origin of these mutations either by founder effect or by migrations is discussed, and raises the question of an adequate strategy to be used adapted to socio-economical status.
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Affiliation(s)
- Nassima Boudrahem-Addour
- Laboratoire de Biologie Cellulaire et Moléculaire, Faculté des Sciences Biologiques, Université des Sciences et de la Technologie Houari Boumediène, Alger, Algérie
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13
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Molecular basis of deletional hereditary persistence of fetal hemoglobin and δβ-thalassemia in Indian patients. Clin Chim Acta 2008; 392:69-70. [DOI: 10.1016/j.cca.2008.02.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2008] [Revised: 02/18/2008] [Accepted: 02/19/2008] [Indexed: 11/20/2022]
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14
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de Vooght KMK, van Wijk R, Rijksen G, van Solinge WW. A family with multiple mutations and sequence variations in the alpha- and beta-globin gene clusters. Clin Chem Lab Med 2008; 46:165-8. [PMID: 18076350 DOI: 10.1515/cclm.2008.037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Usually, laboratory diagnostics of hereditary hemoglobin disorders is fairly straightforward. Sometimes, however, correct diagnosis can be difficult. In this study, we describe a family with multiple mutations and sequence variations in the alpha- and beta-globin gene clusters. METHODS Hemocytometry results were obtained using an automated cell counter. Hemoglobin variant analysis was performed by cation-exchange HPLC. PCR and DNA sequence analyses were used to identify mutations in the globin genes. RESULTS The proposita was referred to our laboratory for hematological evaluation [hemoglobin 145 g/L (119-155 g/L) mean corpuscular volume 72 fl (80-97 fl), mean corpuscular hemoglobin 26 pg (28-36 pg), erythrocytes 5.6 x 10(12)/L (3.7-5.0 10(12)/L)]. Characterization and quantification of hemoglobin variants showed 11.3% HbA1, 4.4% HbA2, 58.9% HbC and 23.0% HbF. Subsequent analysis revealed, in addition to a heterozygous HbC mutation, the presence of a beta-thalassemia causing mutation (-90C>T), a heterozygous alpha-thalassemia (-alpha(-3.7)/alpha alpha) and three different gamma-globin sequence variations. Additional molecular analysis was performed in all family members. CONCLUSIONS In the family presented in this study, 10 different mutations were found in the globin genes. Molecular analysis was necessary to clarify hemoglobin variant analysis, in particular the low amount of HbA1 in the proposita. Knowledge of the molecular background facilitates in the understanding of the hematological parameters and proper counseling of the patient.
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Affiliation(s)
- Karen M K de Vooght
- Department of Clinical Chemistry and Haematology, Laboratory for Red Blood Cell Research, University Medical Center Utrecht, Utrecht, The Netherlands
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15
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Edison ES, Shaji RV, Devi SG, Moses A, Viswabandhya A, Mathews V, George B, Srivastava A, Chandy M. Analysis of beta globin mutations in the Indian population: presence of rare and novel mutations and region-wise heterogeneity. Clin Genet 2008; 73:331-7. [PMID: 18294253 DOI: 10.1111/j.1399-0004.2008.00973.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Beta thalassaemia is a major public health problem in India. A comprehensive database of the spectrum of mutations causing beta thalassaemia in the Indian population is necessary. This study in which a large number of patients with beta thalassaemia including those from certain regions that were not explored earlier shows a great heterogeneity of mutations. Several novel and rare alleles that have not been reported earlier in the Indian population have been identified, and mutations differ in frequency in different regions of the country. This information on the spectrum of mutations has implications for the control of beta thalassaemia in a population with complex ethnic background and also on the genotype-phenotype correlation of the disease.
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Affiliation(s)
- E S Edison
- Department of Haematology, Christian Medical College, Vellore, Tamilnadu, India
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16
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Morgado A, Picanço I, Gomes S, Miranda A, Coucelo M, Seuanes F, Seixas MT, Romão L, Faustino P. Mutational spectrum of delta-globin gene in the Portuguese population. Eur J Haematol 2007; 79:422-8. [PMID: 17916081 DOI: 10.1111/j.1600-0609.2007.00949.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The phenotype of increased Hb A2 typical of beta-thalassaemia (beta-thal) carriers can be reduced to normal or borderline values because of the co-inheritance of a delta-globin gene (HBD, MIM #142000) mutation, which may lead to misinterpretation of diagnostic results. To know the spectrum of delta-globin mutations in the Portuguese population we performed a mutational analysis of the delta-globin gene in a group of 51 Portuguese beta-thal carriers presenting microcytosis, hypochromia and a normal/borderline Hb A2 level and in another group of 15 individuals suspected to have delta-globin structural abnormalities. The heterozygosity for the beta(+)IVS-I-6T-->C (HBB:c. 92+6T>C) mutation was the main cause for the mentioned atypical beta-thal carrier phenotype. Furthermore, eight individuals were double heterozygous for one common beta-thal mutation and the delta(+)Cd27G-->T mutation (Hb A2-Yialousa; HBD:c.82G>T). One of them also presented a novel delta-globin gene promoter mutation,-80G-->A (HBD:c.-130G>A), responsible for about 25% decrease of the promoter activity in transient expression assays. One the other hand, in the other group of 15 individuals suspected to have delta-globin structural abnormalities observed by biochemical methods, some known Hb A2 variants were identified - Hb A2' (HBD:c.49G>C), Hb A2-Babinga (HBD:c.410G>A), and Hb A2-Wrens (HBD:c.295G>A), and the novel Hb A2-Fogo [delta64(E8)(Gly-->Ser); (HBD:c.193G>A)]. This novel Hb A2 variant was observed segregating in linkage with Hb E (HBB:c.79G>A) in a three generation family. In conclusion, six different delta-globin mutations were found, being two of them new molecular defects. All delta-alleles identified were found linked to the expected beta-globin cluster haplotype. All mutations caused a low Hb A2 level and through this could lead to misdiagnosis when inherited together with a beta-thal allele.
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Affiliation(s)
- Ana Morgado
- Centro de Genética Humana, Instituto Nacional de Saúde Dr Ricardo Jorge, Lisboa, Portugal
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17
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Lemsaddek W, Picanço I, Seuanes F, Mahmal L, Benchekroun S, Khattab M, Nogueira P, Osório-Almeida L. Spectrum of beta thalassemia mutations and HbF levels in the heterozygous Moroccan population. Am J Hematol 2003; 73:161-8. [PMID: 12827652 DOI: 10.1002/ajh.10358] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A comprehensive hematological and molecular analysis of 57 beta thalassemic heterozygotes, 28 homozygotes, 18 double heterozygotes, 3 compound heterozygotes beta thal/beta S and one compound heterozygote beta thal/Hb Newcastle, in 46 Moroccan families with at least one beta thalassemia patient is reported. Six major mutations: beta(0)39 (C-->T), beta(0)FsCD8(-AA), beta(+)IVS1,nt6 (T-->C) and beta(0)IVS1,nt1 (G-->A), beta(0)FsCD6 (-A) and beta(+)-29 (A-->G) cap site account for 75% of the 86 independent beta thal chromosomes studied. For the first time, an extensive mutation/haplotype study has been performed on the Moroccan population, and data are consistent with the geographical location of the country and historical links with both the Mediterranean and the Sub-Saharan Africa communities. Despite the heterogeneous spectrum of mutations, good genetic counseling can be offered to the carrier population. This study focuses on the analysis of fetal hemoglobin levels in beta thalassemic heterozygotes and its correlation with beta globin cluster polymorphic markers in this population. Fetal hemoglobin levels in heterozygotes vary from trace quantities to 17.9% (2.38 g/dl) of total hemoglobin in the adult. No statistically significant correlation was found, either between genders and HbF levels, or between the mutation and the HbF level, with the exception of mutation beta(0)FSCD6(-A). We have examined the alpha globin genotype and the beta globin genotype of heterozygotes, namely, the extended haplotype, which includes the XmnI site at -158 bp of the Ggamma gene and the microsatellite (AT)(x)T(y) at -540 bp of the beta globin gene. In this sample, we confirm the existence of linkage disequilibrium between the C-->T variation at -158 bp of Ggamma globin gene (XmnI(+)) and Orkin's haplotypes III, IV, or IX (the 5' subhaplotype class A). At 5' beta globin gene, we observe exclusively the allele (AT)(7)T(7). In the beta thalassemic heterozygotes studied, no correlation of those genetic markers with HbF levels is observed.
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Affiliation(s)
- Wafaa Lemsaddek
- Laboratório de Genética Molecular, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
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18
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Fisher CA, Premawardhena A, de Silva S, Perera G, Rajapaksa S, Olivieri NA, Old JM, Weatherall DJ. The molecular basis for the thalassaemias in Sri Lanka. Br J Haematol 2003; 121:662-71. [PMID: 12752111 DOI: 10.1046/j.1365-2141.2003.04346.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The beta-globin gene mutations and the alpha-globin genes of 620 patients with the phenotype of severe to moderate thalassaemia from seven centres in Sri Lanka were analysed. Twenty-four beta-globin gene mutations were identified, three accounting for 84.5% of the 1240 alleles studied: IVSI-5 (G-->C) 56.2%; IVSI-1 (G-->A) 15.2%; and haemoglobin E (codon (CD)26 GAG-->GAA) 13.1%. Three new mutations were found; a 13-bp deletion removing the last nucleotide in CD6 to CD10 inclusively, IVSI-129 (A-->C) in the consensus splice site, and a frame shift, CD55 (-A). The allele frequency of alpha+ thalassaemia was 6.5% and 1.1% for -alpha3.7 and -alpha4.2 deletions respectively. Non-deletion alpha-thalassaemia was not observed. Triplicate or quadruplicate alpha-globin genes were unusually common. In 1.5% of cases it was impossible to identify beta-thalassaemia alleles, but in Kurunegala detailed family studies led to an explanation for the severe thalassaemia phenotype in every case, including a previously unreported instance of homozygosity for a quadruplicated alpha-globin gene together with beta-thalassaemia trait. These findings have implications for the control of thalassaemia in high-frequency populations with complex ethnic histories.
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Affiliation(s)
- Christopher A Fisher
- Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK.
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19
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Gonçalves I, Henriques A, Raimundo A, Picanço I, Reis A, Correia Junior E, Santos E, Nogueira P, Osório-Almeida L. Fetal hemoglobin elevation in Hb Lepore heterozygotes and its correlation with beta globin cluster linked determinants. Am J Hematol 2002; 69:95-102. [PMID: 11835344 DOI: 10.1002/ajh.10019] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
We have analysed, at the hematological and molecular level, 51 Hb lepore heterozygotes and three compound heterozygotes for Hb Lepore and HbS (HbLep/HbS) in 26 unselected Portuguese families. The Lepore Boston variant was present in one family, in association with classical haplotype V. All of the other Lepore alleles present haplotype III in association with XmnI (+)5' of (G)gamma gene, in tight linkage disequilibrium to the major mutation found in the Portuguese population, the Lepore Baltimore variant ( delta(68Leu)-beta(84Thr)). The three compound heterozygotes are the first HbLep/HbS individuals reported in the literature, with the Lepore Baltimore mutation linked to haplotype III. In agreement with other studies, these Lepore Baltimore heterozygotes have higher HbF (1.4-14.1% of total hemoglobin) than published cases of Lepore Boston (0.8-5.4%), which is associated with XmnI(-). Among the Lepore Baltimore heterozygotes, the (AT)xTy repeat region at -540 bp of the beta globin gene in trans to the Lepore chromosome, can account for much of the variability in HbF level. The allele (AT)7T7 is associated with lower HbF, and (AT)9T5 is associated with higher HbF. As we previously reported for beta thalassemic carriers, we observe in Lepore Baltimore carriers an effector in trans, linked to the (AT)xTy sequence, acting as an HPFH (Hereditary Persistence of Fetal Hemoglobin) determinant.
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Affiliation(s)
- Isabel Gonçalves
- Laboratório de Genética Molecular, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
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20
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Faustino P, Pacheco P, Loureiro P, Nogueira PJ, Lavinha J. The geographic pattern of beta-thalassaemia mutations in the Portuguese population. Br J Haematol 1999; 107:903-4. [PMID: 10671033 DOI: 10.1046/j.1365-2141.1999.01821.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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21
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Cabeda JM, Correia C, Estevinho A, Simoes C, Amorim ML, Pinho L, JusticA B. Unexpected pattern of beta-globin mutations in beta-thalassaemia patients from northern Portugal. Br J Haematol 1999. [DOI: 10.1111/j.1365-2141.1999.01295.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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22
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Gonçalves I, Ducrocq R, Lavinha J, Nogueira PJ, Peres MJ, Picanço I, Correia E, Reis AB, Silva C, Krishnamoorthy R, Almeida LO. Combined effect of two different polymorphic sequences within the beta globin gene cluster on the level of HbF. Am J Hematol 1998; 57:269-76. [PMID: 9544969 DOI: 10.1002/(sici)1096-8652(199804)57:4<269::aid-ajh1>3.0.co;2-s] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Beta thalassemia and Hb Lepore heterozygotes included in this study exhibit fetal hemoglobin levels varying from trace quantities to 14% (1.74 g/dl) of total hemoglobin in the adult. In this work, we have examined the correlation of DNA sequence polymorphisms with the observed HbF level. The analysis of polymorphic markers within the beta globin cluster in 39 individuals heterozygous for beta thalassemia or Hb Lepore confirms the previous findings for homozygous beta thalassemia: the presence of both an (AT)9 T5 sequence configuration at position -540 of the beta globin gene and a (C --> T) variation at -158 of the Ggamma globin gene is associated with elevated expression of HbF. However, at least one defective beta globin gene is required to reveal this association. The best evidence is from the study of individuals heterozygous for Hb Lepore with various levels of HbF. In these individuals it was possible to explore the effect of a single (AT)x Ty motif (the other being absent from the rearranged Lepore chromosome) on HbF expression. The presence of the (AT)9 T5 configuration increases HbF level from a median of 0.515 g/dl observed in (AT)7 T7 subjects, to 1.39 g/dl. We confirm the existence of linkage disequilibrium between the (C --> T) variation at -158 of Ggamma gene and the (TG)13 configuration at the second intervening sequence (IVS-2) of Agamma gene and identify two new polymorphisms in this region: (TG)7 (CG)5 (TG)8 linked to haplotype V and (TG)8 (CG)5 (TG)10 linked to haplotype II. This study suggests that two distinct regions of the beta cluster, whether in cis or in trans to each other, can interact to enhance HbF expression when a beta thalassemic determinant is present in heterozigosity.
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Affiliation(s)
- I Gonçalves
- Laboratório de Genética Molecular, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Monte da Caparica, Portugal
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23
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Flint J, Harding RM, Boyce AJ, Clegg JB. The population genetics of the haemoglobinopathies. BAILLIERE'S CLINICAL HAEMATOLOGY 1998; 11:1-51. [PMID: 10872472 DOI: 10.1016/s0950-3536(98)80069-3] [Citation(s) in RCA: 218] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The haemoglobinopathies are the commonest single-gene disorders known, almost certainly because of the protection they provide against malaria, as attested by a number of observations. The geographical distributions of malaria and haemoglobinopathies largely overlap, and microepidemiological surveys confirm the close relationship between them. For two of the commonest disorders, haemoglobin S and alpha(+)-thalassaemia, there is also good clinical evidence for protection against malaria morbidity. However, not all the evidence appears to support this view. In some parts of the world malaria and haemoglobinopathies are not, and never have been, coexistent. It is also difficult to explain why the majority of haemoglobinopathies appear to be recent mutations and are regionally specific. Here we argue that these apparent inconsistencies in the malaria hypothesis are the result of processes such as genetic drift and migration and of demographic changes that have occurred during the past 10,000 years. When these factors are taken into account, selection by malaria remains the force responsible for the prevalence of the haemoglobinopathies.
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Affiliation(s)
- J Flint
- Institute of Molecular Medicine, John Radcliffe Hospital, Headington, Oxford, UK
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24
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Affiliation(s)
- T H Huisman
- Editorial Office, HEMOGLOBIN, Medical College of Georgia, Augusta 30912-2100, USA
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25
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Dominantly Transmitted β-Thalassemia Arising From the Production of Several Aberrant mRNA Species and One Abnormal Peptide. Blood 1998. [DOI: 10.1182/blood.v91.2.685] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AbstractWe describe a dominantly inherited β-thalassemia intermedia phenotype observed in a five-generation Portuguese family. Carriers are characterized by moderate anemia, hypochromia, microcytosis, elevated hemoglobin (Hb)A2 and HbF levels, splenomegaly, hepatomegaly, and inclusion bodies in pheripheral red blood cells after splenectomy. The molecular basis of this condition is a small deletion within the 5′ consensus splicing sequence of the second intron of the β-globin gene, IVS-II-4,5 (-AG). Reticulocyte RNA studies performed by reverse transcription-polymerase chain reaction (RT-PCR) and primer extension analysis showed three abnormally processed transcripts, which, upon sequencing, were shown to correspond to (1) skipping of exon 2, and (2) activation of two cryptic splice sites (between codons 59/60, and at IVS-II-47). In vitro translation studies of these patients' reticulocyte RNA have shown that at least one of these aberrant mRNA species is translated into an abnormally elongated peptide whose cytotoxic properties could, in part, be causing the atypical dominant mode of inheritance observed in this family. We suggest that this elongated β chain is unable to combine with an α-globin chain to form a functional Hb molecule. Its degradation would, then, exhaust the proteolytic defense mechanism of the erythroid precursors, leading to inefficient proteolysis of the free α chains in excess.
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26
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Dominantly Transmitted β-Thalassemia Arising From the Production of Several Aberrant mRNA Species and One Abnormal Peptide. Blood 1998. [DOI: 10.1182/blood.v91.2.685.685_685_690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We describe a dominantly inherited β-thalassemia intermedia phenotype observed in a five-generation Portuguese family. Carriers are characterized by moderate anemia, hypochromia, microcytosis, elevated hemoglobin (Hb)A2 and HbF levels, splenomegaly, hepatomegaly, and inclusion bodies in pheripheral red blood cells after splenectomy. The molecular basis of this condition is a small deletion within the 5′ consensus splicing sequence of the second intron of the β-globin gene, IVS-II-4,5 (-AG). Reticulocyte RNA studies performed by reverse transcription-polymerase chain reaction (RT-PCR) and primer extension analysis showed three abnormally processed transcripts, which, upon sequencing, were shown to correspond to (1) skipping of exon 2, and (2) activation of two cryptic splice sites (between codons 59/60, and at IVS-II-47). In vitro translation studies of these patients' reticulocyte RNA have shown that at least one of these aberrant mRNA species is translated into an abnormally elongated peptide whose cytotoxic properties could, in part, be causing the atypical dominant mode of inheritance observed in this family. We suggest that this elongated β chain is unable to combine with an α-globin chain to form a functional Hb molecule. Its degradation would, then, exhaust the proteolytic defense mechanism of the erythroid precursors, leading to inefficient proteolysis of the free α chains in excess.
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27
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Pacheco P, Peres MJ, Faustino P, Pischedda C, Gonçalves J, Carvajales-Ramos M, Seixas T, Martins MC, Moi P, Lavinha J. Beta-thalassaemia unlinked to the beta-globin gene interacts with sickle-cell trait in a Portuguese family. Br J Haematol 1995; 91:85-9. [PMID: 7577658 DOI: 10.1111/j.1365-2141.1995.tb05249.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
An autosomally transmitted hypochromic microcytic mild anaemia with elevated haemoglobin (Hb) A2 and globin chain imbalance has been observed in a three-generation family of Portuguese origin. Extensive DNA analysis of the beta-globin gene cluster, including the complete sequencing of the beta-globin gene and flanking regions, failed to reveal any genetic alteration. The co-segregation of sickle-cell trait in this family enabled us to postulate a defective erythroid trans-acting factor was playing a role in the down-regulation of both beta A- and beta S-globin genes. Among the transcription factors that could possibly have caused the reported phenotype, NF-E2 is unlikely to be implicated, whereas Nrf1 and Nrf2 cannot be ruled out. Thus, this family carries a novel beta-thalassaemia autosomal determinant unlinked to the beta-globin gene. This observation reinforces the notion of the haemoglobinopathies as single gene disorders under polygenic regulation.
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Affiliation(s)
- P Pacheco
- Departamento de Genética Humana, Instituto Nacional de Saúde Dr Ricardo Jorge, Lisboa
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28
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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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29
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Peres MJ, Romão L, Carreiro H, Picanço I, Batalha L, Magalhães HA, Martins MC, Lavinha J. Molecular basis of alpha-thalassemia in Portugal. Hemoglobin 1995; 19:343-52. [PMID: 8718693 DOI: 10.3109/03630269509005826] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
We have estimated the incidence and molecular basis of alpha-thalassemia in a Portuguese population, mostly from the Greater Lisbon area. In a group of 100 consecutive cord blood samples, the gene frequency of the rightward deletion (-alpha 3.7) was 0.035, and the leftward deletion (-alpha 4.2) was 0.015. In this group, we have also found four heterozygotes for the triple alpha-globin gene rearrangement (alpha alpha alpha anti 3.7. gene frequency 0.020). We have characterized the subtypes of -alpha 3.7 and alpha alpha alpha anti 3.7 rearrangements. On the whole, these results give an incidence of 10% for deletional alpha-thalassemia carriers in the studied Portuguese population. In a group of 342 subjects presenting beta-thalassemia, or Hb S trait, beta-thalassemia major sickle cell disease or low red blood cell indices, the -alpha 3.7, -alpha 4.2, -SEA, -MED, (alpha alpha)MM, and alpha alpha alpha anti 3.7 haplotypes were found in different combinations. Only one nondeletional alpha-thalassemia determinant (a 5 nucleotide deletion in the alpha 2-globin gene in the second intervening sequence donor site) was detected, which might suggest a low incidence of these defects in the Portuguese population.
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Affiliation(s)
- M J Peres
- Departamento de Biologia Médica, Instituto Nacional de Saúde Dr Ricardo Jorge, Lisboa, Portugal
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30
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Martins MC, Olim G, Melo J, Magalhães HA, Rodrigues MO. Hereditary anaemias in Portugal: epidemiology, public health significance, and control. J Med Genet 1993; 30:235-9. [PMID: 8474108 PMCID: PMC1016307 DOI: 10.1136/jmg.30.3.235] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
A countrywide prospective study aimed at establishing the prevalence of the haemoglobinopathy genes in the Portuguese population was carried out by screening 15,208 randomly selected blood samples from young males. This male based survey provided the opportunity of assessing simultaneously the prevalence of the red cell enzyme glucose-6-phosphate dehydrogenase (G6PD) deficiency, thus giving a picture of these important hereditary anaemias in Portugal. The results showed a low average frequency of beta thalassaemia (0.45%) and haemoglobin S (0.32%) carriers as well as G6PD deficiency (0.51%). However, these disorders are unevenly distributed throughout the country with a higher prevalence in some areas, mainly in the south. The relationship of this pattern of haemoglobinopathies to the known haplotypes linked to beta thalassaemia and sickle cell disease, relevant historical events, and local selective pressure was investigated. Hb D and Hb J are the commonest other structural variants. The implemented programme for control of these hereditary anaemias is described.
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Affiliation(s)
- M C Martins
- Laboratório de Química, Clínica/Hematologia, Instituto Nacional de Saude, Lisboa, Portugal
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Oppenheim A, Oron V, Filon D, Fearon CC, Rachmilewitz EA, Kazazian HH, Rund D. Sporadic alleles, including a novel mutation, characterize beta-thalassemia in Ashkenazi Jews. Hum Mutat 1993; 2:155-7. [PMID: 8318995 DOI: 10.1002/humu.1380020219] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- A Oppenheim
- Department of Hematology, Hadassah University Hospital, Jerusalem, Israel
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Abstract
Mutations in gene promoter/regulatory regions represent an important class of lesion causing human genetic disease. Such mutations are associated with either increases or decreases in transcriptional activity mediated by the altered binding behaviour of trans-acting protein factors to specific DNA sequences in the promoter region. Although most promoter mutations are individually very infrequent, some occur at polymorphic frequencies. Both categories of lesion are likely to be important in clinical medicine and their study has already led to new insights into the mechanisms underlying the regulation of human genes.
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Affiliation(s)
- D N Cooper
- Charter Molecular Genetics Laboratory, Thrombosis Research Institute, London, U.K
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