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Waye JS, Eng B, Hanna M, Hohenadel BA, Nakamura L, Walker L. α 0-Thalassemia Due to a 90.7 kb Deletion (- - NFLD). Hemoglobin 2017; 41:218-219. [PMID: 28838269 DOI: 10.1080/03630269.2017.1369987] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
We report an α0-thalassemia (α0-thal) trait in Newfoundlanders caused by a novel 90.7 kb deletion. The deletion, designated the Newfoundland deletion (- -NFLD), removes both the HBA2 and HBA1 genes, while leaving the HBZ gene intact. The 5' deletion endpoint is within the HBAP1 pseudogene, approximately 3.7 kb upstream of the HBA2 gene. The 3' deletion endpoint is approximately 82.5 kb downstream of the HBA1 gene, within the second intervening sequence (IVS-II) of the FAM234A gene. This is the second α0-thal deletion reported in Newfoundland families of northern European descent.
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Affiliation(s)
- John S Waye
- a Hamilton Regional Laboratory Medicine Program , Hamilton Health Sciences , Hamilton , Ontario , Canada.,b Department of Pathology and Molecular Medicine , McMaster University , Hamilton , Ontario , Canada
| | - Barry Eng
- a Hamilton Regional Laboratory Medicine Program , Hamilton Health Sciences , Hamilton , Ontario , Canada
| | - Meredith Hanna
- a Hamilton Regional Laboratory Medicine Program , Hamilton Health Sciences , Hamilton , Ontario , Canada
| | - Betty-Ann Hohenadel
- a Hamilton Regional Laboratory Medicine Program , Hamilton Health Sciences , Hamilton , Ontario , Canada
| | - Lisa Nakamura
- a Hamilton Regional Laboratory Medicine Program , Hamilton Health Sciences , Hamilton , Ontario , Canada
| | - Lynda Walker
- a Hamilton Regional Laboratory Medicine Program , Hamilton Health Sciences , Hamilton , Ontario , Canada
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2
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Abstract
Alpha-thalassaemia is inherited as an autosomal recessive disorder characterised by a microcytic hypochromic anaemia, and a clinical phenotype varying from almost asymptomatic to a lethal haemolytic anaemia. It is probably the most common monogenic gene disorder in the world and is especially frequent in Mediterranean countries, South-East Asia, Africa, the Middle East and in the Indian subcontinent. During the last few decades the incidence of alpha thalassaemia in North-European countries and Northern America has increased because of demographic changes. Compound heterozygotes and some homozygotes have a moderate to severe form of alpha thalassaemia called HbH disease. Hb Bart's hydrops foetalis is a lethal form in which no alpha-globin is synthesized. Alpha thalassaemia most frequently results from deletion of one or both alpha genes from the chromosome and can be classified according to its genotype/phenotype correlation. The normal complement of four functional alpha-globin genes may be decreased by 1, 2, 3 or all 4 copies of the genes, explaining the clinical variation and increasing severity of the disease. All affected individuals have a variable degree of anaemia (low Hb), reduced mean corpuscular haemoglobin (MCH/pg), reduced mean corpuscular volume (MCV/fl) and a normal/slightly reduced level of HbA2. Molecular analysis is usually required to confirm the haematological observations (especially in silent alpha-thalassaemia and alpha-thalassaemia trait). The predominant features in HbH disease are anaemia with variable amounts of HbH (0.8-40%). The type of mutation influences the clinical severity of HbH disease. The distinguishing features of the haemoglobin Bart's hydrops foetalis syndrome are the presence of Hb Bart's and the total absence of HbF. The mode of transmission of alpha thalassaemia is autosomal recessive. Genetic counselling is offered to couples at risk for HbH disease or haemoglobin Bart's Hydrops Foetalis Syndrome. Carriers of alpha+- or alpha0-thalassaemia alleles generally do not need treatment. HbH patients may require intermittent transfusion therapy especially during intercurrent illness. Most pregnancies in which the foetus is known to have the haemoglobin Bart's hydrops foetalis syndrome are terminated due to the increased risk of both maternal and foetal morbidity.
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Affiliation(s)
- Cornelis L Harteveld
- 1Department of Human and Clinical Genetics, Leiden University Medical Center, Einthovenweg 20, 2333ZC Leiden, The Netherlands
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3
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Eng B, Greenlay B, Waye JS. Characterisation of the British alpha 0-thalassaemia deletion: evidence of a founder effect in Newfoundland, Canada. Br J Haematol 2009; 147:150-2. [PMID: 19622095 DOI: 10.1111/j.1365-2141.2009.07825.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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4
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Ozgönenel B, Savaşan S. Leftward -alpha4.2 deletion alpha-thalassemia in a patient of northern European extraction. J Pediatr Hematol Oncol 2004; 26:29-30. [PMID: 14707709 DOI: 10.1097/00043426-200401000-00010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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6
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Abstract
alpha-Thalassaemias are genetic defects extremely frequent in some populations and are characterized by the decrease or complete suppression of alpha-globin polypeptide chains. The gene cluster, which codes for and controls the production of these polypeptides, maps near the telomere of the short arm of chromosome 16, within a G + C rich and early-replicating DNA region. The genes expressed during the embryonic (zeta) or fetal and adult stage (alpha 2 and alpha 1) can be modified by point mutations which affect either the processing-translation of mRNA or make the polypeptide chains extremely unstable. Much more frequent are the deletions of variable size (from approximately 3 to more than 100 kb) which remove one or both alpha genes in cis or even the whole gene cluster. Deletions of a single gene are the result of unequal pairing during meiosis, followed by reciprocal recombination. These unequal cross-overs, which produce also alpha gene triplications and quadruplications, are made possible by the high degree of homology of the two alpha genes and of their flanking sequences. Other deletions involving one or more genes are due to recombinations which have taken place within non-homologous regions (illegitimate recombinations) or in DNA segments whose homology is limited to very short sequences. Particularly interesting are the deletions which eliminate large DNA areas 5' of zeta or of both alpha genes. These deletions do not include the structural genes but, nevertheless, suppress completely their expression. Larger deletions involving the tip of the short arm of chromosome 16 by truncation, interstitial deletions or translocations result in the contiguous gene syndrome ATR-16. In this complex syndrome alpha-thalassaemia is accompanied by mental retardation and variable dismorphic features. The study of mutations of the 5' upstream flanking region has led to the discovery of a DNA sequence, localized 40 kb upstream of the zeta-globin gene, which controls the expression of the alpha genes (alpha major regulatory element or HS-40). In the acquired variant of haemoglobin H (HbH) disease found in rare individuals with myelodysplastic disorders and in the X-linked mental retardation associated with alpha-thalassaemia, a profound reduction or absence of alpha gene expression has been observed, which is not accompanied by structural alterations of the coding or controlling regions of the alpha gene complex. Most probably the acquired alpha-thalassaemia is due to the lack of soluble activators (or presence of repressors) which act in trans and affect the expression of the homologous clusters and are coded by genes not (closely) linked to the alpha genes. The ATR-X syndrome results from mutations of the XH2 gene, located on the X chromosome (Xq13.3) and coding for a transacting factor which regulates gene expression. The interaction of the different alpha-thalassaemia determinants results in three phenotypes: the alpha-thalassaemic trait, clinically silent and presenting only limited alterations of haematological parameters, HbH disease, characterized by the development of a haemolytic anaemia of variable degree, and the (lethal) Hb Bart's hydrops fetalis syndrome. The diagnosis of alpha-thalassaemia due to deletions is implemented by the electrophoretic analysis of genomic DNA digested with restriction enzymes and hybridized with specific molecular probes. Recently polymerase chain reaction (PCR) based strategies have replaced the Southern blotting methodology. The straightforward identification of point mutations is carried out by the specific amplification of the alpha 2 or alpha 1 gene by PCR followed by the localization and identification of the mutation with a variety of screening systems (denaturing gradient gel electrophoresis (DGGE), single strand conformation polymorphisms (SSCP)) and direct sequencing.
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Affiliation(s)
- L F Bernini
- Institute of Human Genetics, Medical Faculty, University of Leiden, Sylvius Laboratory, The Netherlands
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7
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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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8
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Waye JS, Eng B, Patterson M, Chui DH, Fernandes BJ. Novel beta 0-thalassemia mutation in a Canadian woman of British descent (codons 72/73, -AGTGA, +T). Hemoglobin 1997; 21:385-7. [PMID: 9255617 DOI: 10.3109/03630269709000671] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- J S Waye
- Provincial Hemoglobinopathy, DNA Diagnostic Laboratory, McMaster University Medical Centre Hamilton, Ontario, Canada
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9
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Kattamis AC, Camaschella C, Sivera P, Surrey S, Fortina P. Human alpha-thalassemia syndromes: detection of molecular defects. Am J Hematol 1996; 53:81-91. [PMID: 8892732 DOI: 10.1002/(sici)1096-8652(199610)53:2<81::aid-ajh5>3.0.co;2-#] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- A C Kattamis
- Department of Pediatrics, Children's Hospital of Philadelphia, University of Pennsylvania School of Medicine 19104, USA
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10
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Shalmon L, Kirschmann C, Zaizov R. A new deletional alpha-thalassemia detected in Yemenites with hemoglobin H disease. Am J Hematol 1994; 45:201-4. [PMID: 8296789 DOI: 10.1002/ajh.2830450302] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A new large deletion from the human alpha-globin gene cluster is characterized. It involves at least 39 kb and includes the two alpha-globin genes, the theta 1-gene, all the pseudogenes, and the two hypervariable regions (HVRs), interzeta-HVR and alpha-globin 3'HVR. The conserved zeta-globin gene has been identified in various restriction fragments of abnormal size. The new deletion was found in four unrelated Israeli patients with Hb H disease, all originating in Yemen, and has been designated--YEM. It is the only two-gene deletion identified in this ethnic group.
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Affiliation(s)
- L Shalmon
- Basil and Gerald Felsenstein Medical Research Center (FMRC), Sackler School of Medicine, Rogoff Medical Research Institute, Beilinson Medical Center, Petah Tikva, Israel
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11
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Huisman TH, Gu LH, Liu JC, Fei YJ, Walker EL. Black alpha-thalassemia-1: partial characterization of an approximately 80 kb deletion which includes the zeta- and alpha-globin genes. Hemoglobin 1993; 17:345-53. [PMID: 7901183 DOI: 10.3109/03630269308997487] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A large novel alpha-thalassemia-1 deletion which includes the zeta-, alpha 2-, alpha 1-, and theta 1-globin genes is described in a Black family living in Georgia and Florida. The deletion which was characterized by restriction enzyme analysis, extends 15 to 35 kb 5' and at least 35 kb 3' to the Cap site of the zeta-globin gene. Mental retardation was not observed. The deletion was present in a 35-year-old male with Hb H disease and his mother; the major hemoglobin type in the propositus was Hb G-Philadelphia or alpha (2)68(E12)Asn-->Lys beta 2 because his second chromosome carried the -alpha G(-3.7 kb) alpha-thalassemia-2 deletion.
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Affiliation(s)
- T H Huisman
- Department of Biochemistry and Molecular Biology Medical College of Georgia, Augusta 30912-2100
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12
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Flint J, Harding RM, Boyce AJ, Clegg JB. The population genetics of the haemoglobinopathies. BAILLIERE'S CLINICAL HAEMATOLOGY 1993; 6:215-62. [PMID: 8353314 DOI: 10.1016/s0950-3536(05)80071-x] [Citation(s) in RCA: 83] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The haemoglobinopathies are the commonest single gene disorders known, and are so common in some regions of the world that the majority of the population carries at least one genetic abnormality affecting the structure or synthesis of the haemoglobin molecule. The prevalence of the common haemoglobinopathies (the alpha- and beta-thalassaemias, HbS, HbC and HbE) is almost certainly a result of the protection they provide against malaria, as the epidemiological evidence reviewed in this chapter shows. World-wide, the distributions of malaria and the common haemoglobinopathies largely overlap, and micro-epidemiological surveys have confirmed the close relationship between the disorders. However, there are complications to this picture which appear to undermine the malaria hypothesis. First, in some areas, malaria and haemoglobinopathies are not coincident. Second, the malaria hypothesis does not easily explain why no two regions of the world have the same haemoglobinopathy or combination of haemoglobinopathies. The majority of mutations have arisen only once and are regionally specific. By using molecular characterization of mutations and the analysis of haplotypes on haemoglobinopathy-bearing chromosomes it is possible to show how a combination of selection by malaria, genetic drift and population movements can explain the first complication. In order to explain the second, we have argued that malaria selection has operated relatively recently on human populations (within the last 5000 years). The present distribution is then seen as the result of selection elevating sporadic mutations in local populations. In the absence of sufficient gene flow to spread all mutations to all populations, the consequence is a patchwork distribution of haemoglobinopathies. Given time, we would expect the mutations that protect and do not compromise the health of their carriers to become widely disseminated, but it is likely that human intervention will alter this process of natural selection.
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Affiliation(s)
- J Flint
- MRC Molecular Haematology Unit, John Radcliffe Hospital, Headington, Oxford, U.K
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13
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Abstract
The large number of naturally occurring mutants of this well-characterized locus provides an excellent opportunity for elucidating the relationship between its structure and function. Comparisons of what has been learned about the alpha-globin locus with complementary observations on the beta-globin locus, provide a strategy for understanding the co-ordinate regulation of eukaryotic gene expression. From a practical point of view it is important to remember that millions of individuals throughout the world are carriers of alpha-thalassaemia and every year many thousands of pregnancies are at risk of producing children with the severe alpha-thalassaemia syndromes. The data summarized here provide the basis for accurately predicting the genotype in such cases and thus enabling appropriate prenatal testing. However, because this is a genetic disease that predominantly affects individuals from countries with limited health resources, simpler and cheaper methods of screening and diagnosis will have to be developed before this information has a significant impact on the attendant morbidity and mortality (see Chapter 9, this volume).
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Affiliation(s)
- D R Higgs
- MRC Molecular Haematology Unit, Institute of Molecular Medicine, Headington, Oxford, U.K
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14
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Fortina P, Dianzani I, Serra A, Gottardi E, Saglio G, Farinasso L, Piga A, Gabutti V, Camaschella C. A newly-characterized alpha-thalassaemia-1 deletion removes the entire alpha-like globin gene cluster in an Italian family. Br J Haematol 1991; 78:529-34. [PMID: 1911344 DOI: 10.1111/j.1365-2141.1991.tb04483.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We describe a new deletional form of alpha thalassaemia which encompasses the entire alpha-like globin gene cluster in a 15-year-old boy of Southern Italian descent. The deletion removes approximately 31 kb, the 5'-end point is located approximately 4 kb upstream of the xi gene, while the 3'-end point maps between the alpha 1- and theta 1-globin genes. The interaction of this deletion with the common-alpha 3.7 form gives origin to a classical form of haemoglobin (Hb) H disease in the propositus of this study. Deletional forms of xi alpha-thalassaemia are uncommon in the Mediterranean basin; as for other unusual xi alpha-thalassaemia forms, heterozygotes for this mutation may escape detection in population surveys based on zeta and alpha probes.
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Affiliation(s)
- P Fortina
- Istituto di Clinica Pediatrica, Università degli Studi, Torino, Italy
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15
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16
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Luzzi GA, Merry AH, Newbold CI, Marsh K, Pasvol G, Weatherall DJ. Surface antigen expression on Plasmodium falciparum-infected erythrocytes is modified in alpha- and beta-thalassemia. J Exp Med 1991; 173:785-91. [PMID: 2007853 PMCID: PMC2190806 DOI: 10.1084/jem.173.4.785] [Citation(s) in RCA: 85] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
In an attempt to determine the mechanism whereby thalassemia in its milder forms may protect against malaria, we have examined the expression of neoantigen at the surface of Plasmodium falciparum-parasitized thalassemic red cells. Neoantigen expression was estimated by measurement of antibody bound after incubation in serum from adults living in a malaria-endemic area, using a quantitative radiometric antiglobulin assay. We found that P. falciparum-parasitized alpha- and beta-thalassemic red cells bind greater levels of antibody from endemic serum than controls: mean binding ratios (+/- SE), respectively, for alpha- and beta-thalassemia compared with controls were 1.69 +/- 0.12 and 1.23 +/- 0.06 on a cell for cell basis, and 1.97 +/- 0.11 and 1.47 +/- 0.08 after a correction for surface area differences. Binding of antibody increased exponentially during parasite maturation. In addition, we found a small but significant degree of binding of naturally occurring antibody to parasitized red cells, the extent of which was also greater in thalassemia. The apparent protective effect of thalassemia against malaria may be related to enhanced immune recognition and hence clearance of parasitized erythrocytes.
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Affiliation(s)
- G A Luzzi
- University of Oxford, John Radcliffe Hospital, Headington, England
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17
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Lebo RV, Saiki RK, Swanson K, Montano MA, Erlich HA, Golbus MS. Prenatal diagnosis of alpha-thalassemia by polymerase chain reaction and dual restriction enzyme analysis. Hum Genet 1990; 85:293-9. [PMID: 1975558 DOI: 10.1007/bf00206749] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Asian couples at risk for a fetus with homozygous alpha-thalassemia (hydrops fetalis) are often identified by their low erythrocyte mean corpuscular volume (MCV) and normal hemoglobin electrophoresis when little time remains to test their genotypes by restriction enzyme analysis. DNA analysis is performed directly on chorionic villi or amniocytes remaining after an aliquot is used to establish a backup cell culture. The polymerase chain reaction (PCR) protocol quickly determines whether the fetus has hydrops fetalis without waiting for cultured cells to grow. Previously, growing cultured fetal cells to obtain more fetal material to establish unambiguously the fetal genotype with two independent restriction enzyme digests absorbed a significant portion of the time remaining to complete prenatal diagnosis. A dual restriction enzyme digestion protocol was development using a 3' zeta-globin probe to clearly distinguish the most common alpha-thalassemia deletions that represent nearly all the alpha-thalassemia haplotypes in Southeast Asia.
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Affiliation(s)
- R V Lebo
- Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Francisco 94143-0720
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18
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Luzzi GA, Torii M, Aikawa M, Pasvol G. Unrestricted growth of Plasmodium falciparum in microcytic erythrocytes in iron deficiency and thalassaemia. Br J Haematol 1990; 74:519-24. [PMID: 2189491 DOI: 10.1111/j.1365-2141.1990.tb06344.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The mechanism(s) underlying the apparent resistance to malaria in certain inherited red cell disorders and iron deficiency anaemia remain poorly understood. The possibility that microcytic erythrocytes might inhibit parasite development, by physical restriction or reduced supply of nutrients, has been considered for many years, and never formally investigated. We sought to determine whether in vitro growth studies of P. falciparum could provide evidence to suggest that small red cell size contributes to malaria resistance in those red cell disorders in which microcytosis is a characteristic feature. Invasion and development of P. falciparum in iron deficient red cells (mean values for mean cell volume [MCV] 66 fl, mean cell haemoglobin [MCH] 19 pg) and in the red cells of two gene deletion forms of alpha-thalassaemia (mean MCV 71 fl, MCH 22 pg) were normal, assessed both morphologically, and by 3H-hypoxanthine incorporation. Although parasite appearances were normal in all cell types, morphological abnormalities were noted in iron deficient and thalassaemic cells parasitized by mature stages of P. falciparum, notably cellular ballooning and extreme hypochromia of the red cell cytoplasm. Using electron microscopy, the red cell cytoplasm in parasitized thalassaemic cells showed reduced electron density and abnormal reticulation. Normal invasion rates were observed following schizogony in microcytic cells of both types. Our findings indicate that whilst minor morphological abnormalities may be detected in parasitized iron deficiency and thalassaemic erythrocytes, development of P. falciparum in these conditions is not limited by small erythrocyte size.
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Affiliation(s)
- G A Luzzi
- Institute of Molecular Medicine, John Radcliffe Hospital, Oxford
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19
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Hattori Y, Morishita M, Yamashiro Y, Yamamoto K, Yamamoto K, Matsuno Y, Ohba Y, Miyaji T. Three Japanese families with Hb H disease: gene analyses and their characterizations. Hemoglobin 1990; 14:559-67. [PMID: 2079436 DOI: 10.3109/03630269009005809] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Y Hattori
- Department of Clinical Laboratory Science, Yamaguchi University School of Medicine, Japan
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20
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Bhavnani M, Wickham M, Ayyub H, Higgs DR. Alpha-thalassaemia in the north west of England. CLINICAL AND LABORATORY HAEMATOLOGY 1989; 11:293-7. [PMID: 2605871 DOI: 10.1111/j.1365-2257.1989.tb00226.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Although it is extremely rare amongst the indigenous population, we have previously identified several British individuals with alpha-thalassaemia. It was to be expected that the underlying molecular defect in these individuals would result from racial admixture; however, we found that many of them share a specific, previously reported determinant of alpha-thalassaemia, referred to as --BRIT (Higgs et al. 1985). Several of these individuals with the --BRIT determinant originated from the North West of England and therefore a more extensive survey of individuals from this area was undertaken. We identified 14 individuals with the --BRIT determinant out of 200,000 individuals studied. These, together with all other known examples bring the total number of cases identified to 36. It seems likely that this almost exclusively British determinant of alpha-thalassaemia (--BRIT) has become established through genetic drift in this population.
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Affiliation(s)
- M Bhavnani
- Department of Haematology, Royal Albert Edward Infirmary, Wigan
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21
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Vickers MA, Higgs DR. A novel deletion of the entire alpha-globin gene cluster in a British individual. Br J Haematol 1989; 72:471-3. [PMID: 2765412 DOI: 10.1111/j.1365-2141.1989.tb07736.x] [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: 01/02/2023]
Affiliation(s)
- M A Vickers
- Nuffield Department of Clinical Medicine, University of Oxford, John Radcliffe Hospital
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22
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Fortina P, Delgrosso K, Rappaport E, Poncz M, Ballas SK, Schwartz E, Surrey S. A large deletion encompassing the entire alpha-like globin gene cluster in a family of northern European extraction. Nucleic Acids Res 1988; 16:11223-35. [PMID: 2905048 PMCID: PMC339006 DOI: 10.1093/nar/16.23.11223] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
We describe a new deletional form of alpha thalassemia segregating in three generations of a family of northern European origin. A full-term female girl had hypochromic, microcytic anemia since early infancy associated with delayed language development, slow growth and weight gain. Hematologic studies suggested the presence of alpha thalassemia. Gene-blotting studies showed no abnormal alpha-like globin gene fragments; however, studies of inheritance of informative polymorphic restriction fragments using zeta, alpha and 3'-alpha-hypervariable region (3'-HVR) probes showed evidence for an extensive deletion encompassing the entire alpha-like globin gene cluster. The 3' breakpoint of this deletion maps beyond the 3'-HVR, a region implicated as a hot spot for the generation of other large deletional events within the alpha-like cluster. The 5' breakpoint maps at least 10 kilobases (kb) 5' to the zeta-globin gene. The minimum size estimate for this deletion is greater than 47 kilobases.
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Affiliation(s)
- P Fortina
- Division of Hematology, Children's Hospital, Philadelphia, PA
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23
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Gonzalez-Redondo JM, Diaz-Chico JC, Malcorra-Azpiazu JJ, Balda-Aguirre MI, Huisman TH. Characterization of a newly discovered alpha-thalassaemia-1 in two Spanish patients with Hb H disease. Br J Haematol 1988; 70:459-63. [PMID: 3219296 DOI: 10.1111/j.1365-2141.1988.tb02517.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
A new deletion of more than 27 kb, removing the psi zeta 1, psi alpha 2, psi alpha 1, alpha 2, alpha 1 and theta 1 globin genes has been found in four members of a Spanish family, including two patients with Hb H disease. The 5' end point of the deletion is located between the zeta and psi zeta genes, and the 3' end of the deletion is downstream of the 3' hypervariable region.
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Affiliation(s)
- J M Gonzalez-Redondo
- Department of Cell and Molecular Biology, Medical College of Georgia, Augusta 30912-2100
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24
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Safaya S, Mullaney P, Rieder RF. Dysfunctional alpha-globin genes in hemoglobin H disease in blacks: variation in restriction fragment size permits the detection of the -alpha/-alpha T genotype. Am J Hematol 1987; 26:329-39. [PMID: 2891296 DOI: 10.1002/ajh.2830260406] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Hemoglobin H (HbH) disease is most often due to deletion of three of the four alpha-globin genes (genotype --/--alpha). In black subjects although the -alpha/chromosome is common, the --/haplotype is very rare and few examples of HbH disease have been detected. We have studied three black siblings with HbH by restriction endonuclease mapping of the alpha-like gene complex (5'-zeta-psi zeta-psi alpha 2-psi alpha 1-alpha 2-alpha 1-3') using zeta- and alpha- specific probes. The presence of size differences in the previously described hypervariable region between the zeta and psi zeta genes results in a restriction fragment length polymorphism which permitted the detection of single alpha genes on both number 16 chromosomes in these subjects. Quantitative DNA hybridization by a slot-blot technique confirmed that their genomes contained two alpha-globin genes. The results establish that in these black subjects HbH disease is associated with dysfunctional alpha-globin genes (genotype: -alpha/-alpha T).
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Affiliation(s)
- S Safaya
- Department of Medicine, State University of New York, Brooklyn 11203
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25
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Nicholls RD, Fischel-Ghodsian N, Higgs DR. Recombination at the human alpha-globin gene cluster: sequence features and topological constraints. Cell 1987; 49:369-78. [PMID: 3032452 DOI: 10.1016/0092-8674(87)90289-3] [Citation(s) in RCA: 248] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
We have characterized 170 kb of DNA around the human alpha-globin gene cluster to enable a systematic analysis of 12 naturally occurring deletions from this region. In 8 deletions, the 3' breakpoints lie within a 6-8 kb segment of DNA, identifying a breakpoint cluster region. Members of the Alu family of repetitive sequences are frequently found at the breakpoints and we describe a novel deletion due to homologous recombination between such repeats. In another deletion the breakpoints are separated by 131 bp of DNA, which we have shown to be transposed from a region 36 kb upstream from the 5' breakpoint where it is present in the inverse orientation. The sizes of these deletions, the nonrandom distribution of their breakpoints, and the nature of the inversion-duplication transposition event suggest that these rearrangements are constrained by the higher-order structure of the alpha-globin cluster.
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26
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Flint J, Hill AV, Weatherall DJ, Clegg JB, Higgs DR. Alpha globin genotypes in two North European populations. Br J Haematol 1986; 63:796-7. [PMID: 3730299 DOI: 10.1111/j.1365-2141.1986.tb07564.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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27
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Wilkinson T, Yakas J, Kronenberg H, Trent RJ. Alpha thalassemia British type (alpha alpha/--Brit) in an Australian family. Pathology 1986; 18:193-5. [PMID: 3020489 DOI: 10.3109/00313028609059458] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Alpha thalassemia is rarely diagnosed in Australian families of British or Northern European ancestry. In 1972, a third generation Australian was shown to have alpha thalassemia. In the absence of known Mediterranean or South East Asian ancestry it was reported as being the first example of alpha thalassemia in an Australian family. Further study of the proposita in 1985 using DNA mapping of the alpha globin gene complex, shows a distinctive molecular defect identical to the British type of alpha thalassemia. The latter is clearly different from the commonly encountered Mediterranean and South East Asian alpha zero haplotypes. Recognition that alpha zero thalassemia occurs in Australians is important since it may produce a microcytic hypochromic anemia. Its inheritance together with other forms of alpha thalassemia may lead to severe Hb H disease or Hb Bart's hydrops fetalis.
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28
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Weatherall DJ, Old JM, Thein SL, Wainscoat JS, Clegg JB. Prenatal diagnosis of the common haemoglobin disorders. J Med Genet 1985; 22:422-30. [PMID: 3001310 PMCID: PMC1049501 DOI: 10.1136/jmg.22.6.422] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
New techniques of DNA analysis have been applied to the prenatal diagnosis of the common haemoglobin disorders. Currently, it is possible to provide a comprehensive programme for the prevention of these conditions, although this entails the use of several different techniques including globin chain synthesis analysis, direct identification of mutations with restriction enzymes, linkage analysis of restriction fragment length polymorphisms, and the use of oligonucleotide probes. At present, the best combination of these approaches has to be worked out for individual populations, but as the techniques of chorion villus sampling and DNA analysis improve it should be possible to rationalise these prenatal diagnosis programmes and thus make them simpler and less expensive.
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