1
|
Wajcman H, de Brevern AG, Riou J, Latouche C, Marden MC, Pissard S. Short in-Frame Insertions/Deletions in the Coding Sequence of the α-Globin Gene. Consequences of the 3D Structure and Resulting Phenotypes: Hb Choisy as an Example. Hemoglobin 2019; 42:287-293. [PMID: 30700179 DOI: 10.1080/03630269.2018.1556683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A small group of hemoglobin (Hb) variants result from 'in-frame' deletion/insertion (del/ins). We describe a new variant of this group (Hb Choisy), found on the α1 gene, which is the exact counterpart of a previously published deletional variant, Hb J-Biskra [codons 51-58 (or codons 52-59) (-24 bp) (-TCTGCCCAGGTTAAGGGCCACGGC); HBA1: c.157_180del (or HBA2)]. In Hb J-Biskra, the sequence Ser-Ala-Gln-Val-Lys-Gly-His-Gly located from positions α52(E1) to α59(E8) is deleted, while in Hb Choisy the same sequence (Ser-Ala-Gln-Val-Lys-Gly-His-Gly) is inserted at position α52(E1). The variant carrying the insertion appears to be less damaging than the one with the deletion. A possible explanation could be that the additional sequence is located in the C to E interhelical region, and is less disturbing to the general structure of the globin chain. This insertion/deletion (ins/del) is likely favored by the repetition, at an interval of 16 nucleotides, of an eight nucleotide sequence. Comparison of variants of this group, found in the HbVar database, shows that structural modifications resulting from insertions are frequently less damaging than that caused by deletions.
Collapse
Affiliation(s)
- Henri Wajcman
- a Institut National de la Sante et de la Recherche Médicale (INSERM) U 955 eq 2 , Institut Mondor de Recherche Biomoléculaire (IMRB) , Créteil , France
| | - Alexandre G de Brevern
- b Biologie Integree du Globule Rouge Unité Mixte de Recherche (UMR)-S1134, INSERM , Université Paris Diderot, Sorbonne, Paris Cite, Université de la Réunion, Université des Antilles , Paris , France.,c Institut National de la Transfusion Sanguine (INTS) , Paris , France.,e Laboratoire d'Excellence GR-Ex , Créteil , France
| | - Jean Riou
- d Assistance Publique-Hôpitaux de Paris (APHP), Département de Génétique , Hôpital Henri Mondor , Créteil , France
| | - Celine Latouche
- d Assistance Publique-Hôpitaux de Paris (APHP), Département de Génétique , Hôpital Henri Mondor , Créteil , France
| | - Michael C Marden
- a Institut National de la Sante et de la Recherche Médicale (INSERM) U 955 eq 2 , Institut Mondor de Recherche Biomoléculaire (IMRB) , Créteil , France.,e Laboratoire d'Excellence GR-Ex , Créteil , France
| | - Serge Pissard
- a Institut National de la Sante et de la Recherche Médicale (INSERM) U 955 eq 2 , Institut Mondor de Recherche Biomoléculaire (IMRB) , Créteil , France.,d Assistance Publique-Hôpitaux de Paris (APHP), Département de Génétique , Hôpital Henri Mondor , Créteil , France.,e Laboratoire d'Excellence GR-Ex , Créteil , France
| |
Collapse
|
2
|
Farashi S, Najmabadi H. Diagnostic pitfalls of less well recognized HbH disease. Blood Cells Mol Dis 2015; 55:387-95. [DOI: 10.1016/j.bcmd.2015.08.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Revised: 08/06/2015] [Accepted: 08/06/2015] [Indexed: 10/23/2022]
|
3
|
Scheps KG, De Paula SM, Bitsman AR, Freigeiro DH, Basack FN, Pennesi SP, Varela V. Coinheritance of a Novel Mutation on theHBA1Gene: c.187delG (p.W62fsX66) [codon 62 (–G) (α1)] with theα212 Patchwork Allele and Hb S [β6(A3)Glu→Val, GAG>GTG;HBB: c.20A>T]. Hemoglobin 2013; 37:492-500. [DOI: 10.3109/03630269.2013.806930] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
4
|
Zhai YS, Tang HS, Zhou JY, Li DZ. A Novel Case of Hb Phnom Penh: Codons 117/118 (+ATC) as a Cause of α+-Thalassemia. Hemoglobin 2012; 36:289-92. [DOI: 10.3109/03630269.2012.665402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
5
|
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.
Collapse
Affiliation(s)
- Cornelis L Harteveld
- 1Department of Human and Clinical Genetics, Leiden University Medical Center, Einthovenweg 20, 2333ZC Leiden, The Netherlands
| | | |
Collapse
|
6
|
Dimisianos G, Traeger-Synodinos J, Vrettou C, Papassotiriou I, Kanavakis E. A Rare 33 bp In‐Frame Deletion (α63–74 or α64–74 or α65–75) in the α1‐Globin Gene Causing α+‐Thalassemia: A Second Observation. Hemoglobin 2009; 28:137-43. [PMID: 15182056 DOI: 10.1081/hem-120035914] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The most frequent defects resulting in alpha-thalassemia (thal) include large deletions that remove one or both of the duplicated alpha-globin genes on chromosome 16. Less commonly, alpha-thal mutations involve single nucleotide substitutions or micro-deletions, leading either directly to decreased alpha-globin chain synthesis by the affected allele, or indirectly through production of hyperunstable variant alpha-globin chains. Here we describe the characterization of a 33 bp in-frame deletion within the alpha1-globin gene, in a woman with hematological findings consistent with an alpha-thal trait. The amino acids predicted to be missing as a result of the 33 bp deletion are at the end of the E helix and the EF corner of the alpha-globin protein chain, and are not normally involved in the heme contact, although it is presumed that alpha-globin chain folding and hemoglobin (Hb) formation will be disrupted. The observation of inclusion and Heinz bodies indicates the synthesis of some abnormal Hb (or globin chains). An identical mutation has been previously observed in a single case, a Canadian individual of Greek descent, indicating that it is a rare mutation, and probably of the same origin. Possible mechanisms underlying the mutation at the DNA level are discussed.
Collapse
Affiliation(s)
- Gerasimos Dimisianos
- Medical Genetics, Athens University, Aghia Sophia Children's Hospital, Athens, Greece
| | | | | | | | | |
Collapse
|
7
|
Siala H, Ouali F, Messaoud T, Sfar R, Fattoum S. First Description in Tunisia of a Point Mutation at Codon 119 (CCT→TCT) in the α1-Globin Gene: Hb Groene Hart in Association with the − α3.7Deletion. Hemoglobin 2009; 29:263-8. [PMID: 16370486 DOI: 10.1080/03630260500308053] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Herein we describe the case of a Tunisian girl who presented with 3% Hb Bart's (gamma4) at birth. At the age of 3 years, she showed microcytosis and hypochromia in the absence of iron deficiency. The first step of molecular analysis was to test for the common Mediterranean mutations and the classical -alpha3.7 deletion was found in the heterozygous state. Since this finding could not explain the level of Hb Bart's at birth, or the hypochromia and microcytosis, all the alpha-globin genes were sequenced. This revealed a rare point mutation at codon 119 (CCT-->TCT) in the alpha1-globin gene, identified for the first time in Tunisia, and which has previously been described as an unstable hemoglobin (Hb) variant named Hb Groene Hart [alpha119(H2)Pro-->Ser (alpha1)]. Here the -alpha3.7/alpha(alpha)119(CCT-->TCT) genotype is responsible for the alpha-thalassemia (thal) trait phenotype.
Collapse
Affiliation(s)
- Hajer Siala
- Laboratoire de Biochimie Clinique, Hôpital d'Enfants, Tunis, Tunisie
| | | | | | | | | |
Collapse
|
8
|
Wajcman H, Traeger-Synodinos J, Papassotiriou I, Giordano PC, Harteveld CL, Baudin-Creuza V, Old J. Unstable and Thalassemic α Chain Hemoglobin Variants: A Cause of Hb H Disease and Thalassemia Intermedia. Hemoglobin 2009; 32:327-49. [DOI: 10.1080/03630260802173833] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
9
|
Kanavakis E, Papassotiriou I, Karagiorga M, Vrettou C, Metaxotou-Mavrommati A, Stamoulakatou A, Kattamis C, Traeger-Synodinos J. Phenotypic and molecular diversity of haemoglobin H disease: a Greek experience. Br J Haematol 2008. [DOI: 10.1111/j.1365-2141.2000.02448.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
10
|
Kanavakis E, Papassotiriou I, Karagiorga M, Vrettou C, Metaxotou-Mavrommati A, Stamoulakatou A, Kattamis C, Traeger-Synodinos J. Phenotypic and molecular diversity of haemoglobin H disease: a Greek experience. Br J Haematol 2000. [DOI: 10.1046/j.1365-2141.2000.02448.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
11
|
Traeger-Synodinos J, Papassotiriou I, Metaxotou-Mavrommati A, Vrettou C, Stamoulakatou A, Kanavakis E. Distinct phenotypic expression associated with a new hyperunstable alpha globin variant (Hb heraklion, alpha1cd37(C2)Pro>0): comparison to other alpha-thalassemic hemoglobinopathies. Blood Cells Mol Dis 2000; 26:276-84. [PMID: 11042028 DOI: 10.1006/bcmd.2000.0307] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Clinical phenotypes associated with abnormal globin chain biosynthesis may result in thalassemia (deficient quantity) or hemolytic anemia (abnormal hemoglobins). However, the phenotypic expression of hyperunstable hemoglobin variants often includes features of thalassemia, along with variable peripheral hemolysis. Hemoglobinopathies caused by highly unstable beta-chain variants have a dominant thalassemia-like phenotype, in which carriers have a clinical expression of thalassemia intermedia, but highly unstable alpha-globin variants are usually only phenotypically apparent when they interact with other alpha-thalassemia mutations. In a child with clinical and hematological features consistent with beta-thalassemia intermedia, DNA analysis excluded any beta-globin gene mutations but characterized a novel deletion cd37(C2)Pro>0 (Hb Heraklion) in the alpha1 globin gene, in trans to a common Mediterranean nondeletion alpha-thalassemia mutation (alpha(Hph)alpha). The deletion of proline at alpha37(C2) is predicted to result in severe instability of the variant hemoglobin, which on interaction with a synthesis-deficient alpha-thalassemia mutation causes a relatively severe dyserythropoietic anemia, representing an alternative phenotype associated with highly unstable alpha-chain variants. Hb Heraklion is the fourth highly unstable alpha-globin variant that we have observed in patients from Greece and Albania. Two variants involve the alpha2-globin gene: Hb Agrinio (alpha29(B10)Leu>Pro) and Hb Adana (alpha59(E8)Gly>Asp), and two the alpha1-gene: Hb Aghia Sophia (alpha62(E11)Val>0) and (Hb Heraklion a37(C2)Pro>0). Each has been observed on interaction with a different alpha-thalassemia mutation and the phenotypes associated with these highly unstable alpha-variants are presented.
Collapse
Affiliation(s)
- J Traeger-Synodinos
- First Department of Pediatrics, University of Athens, St. Sophia's Children's Hospital, Athens, 11527, Greece
| | | | | | | | | | | |
Collapse
|