scholarly journals Importance of Sequencing HBA1, HBA2 and HBB Genes to Confirm the Diagnosis of High Oxygen Affinity Hemoglobin

Genes ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 132
Author(s):  
Mathilde Filser ◽  
Betty Gardie ◽  
Mathieu Wemeau ◽  
Patricia Aguilar-Martinez ◽  
Muriel Giansily-Blaizot ◽  
...  
Keyword(s):  
Venous Blood ◽  
Real Life ◽  
Oxygen Affinity ◽  
Electrophoretic Analysis ◽  
High Oxygen ◽  
Beta Globin ◽  
Globin Chains ◽  
High Oxygen Affinity ◽  
Idiopathic Erythrocytosis ◽  
Rule Out

High oxygen affinity hemoglobin (HOAH) is the main cause of constitutional erythrocytosis. Mutations in the genes coding the alpha and beta globin chains (HBA1, HBA2 and HBB) strengthen the binding of oxygen to hemoglobin (Hb), bringing about tissue hypoxia and a secondary erythrocytosis. The diagnosis of HOAH is based upon the identification of a mutation in HBA1, HBA2 or HBB in specialized laboratories. Phenotypic studies of Hb are also useful, but electrophoretic analysis can be normal in 1/3 of cases. The establishment of the dissociation curve of Hb can be used as another screening test, a shift to the left indicating an increased affinity for Hb. The direct measurement of venous P50 using a Hemox Analyzer is of great importance, but due to specific analytic conditions, it is only available in a few specialized laboratories. Alternatively, an estimated measurement of the P50 can be obtained in most of the blood gas analyzers on venous blood. The aim of our study was therefore to determine whether a normal venous P50 value could rule out HOAH. We sequenced the HBB, HBA1 and HBA2 genes of 75 patients with idiopathic erythrocytosis. Patients had previously undergone an exhaustive medical check-up after which the venous P50 value was defined as normal. Surprisingly, sequencing detected HOAH in three patients (Hb Olympia in two patients, and Hb St Nazaire in another). A careful retrospective examination of their medical files revealed that (i) one of the P50 samples was arterial; (ii) there was some air in another sample; and (iii) the P50 measurement was not actually done in one of the patients. Our study shows that in real life conditions, due to pre-analytical contingencies, a venous P50 value that is classified as being normal may not be sufficient to rule out a diagnosis of HOAH. Therefore, we recommend the systematic sequencing of the HBB, HBA1 and HBA2 genes in the exploration of idiopathic erythrocytosis.

Hemoglobin fort gordon or α2β2145 Tyr → Asp, a new high-oxygen-affinity hemoglobin variant

1975 ◽  
Vol 400 (2) ◽  
pp. 343-347 ◽  
Author(s):  
H.B. Kleckner ◽  
J.B. Wilson ◽  
J.G. Lindeman ◽  
P.D. Stevens ◽  
G. Niazi ◽  
...  
Keyword(s):  
Oxygen Affinity ◽  
High Oxygen ◽  
Hemoglobin Variant ◽  
High Oxygen Affinity

Germline mosaicism for an alanine to valine substitution at residue ? 140 in hemoglobin Puttelange, a new variant with high oxygen affinity

1995 ◽  
Vol 96 (6) ◽  
pp. 711-716 ◽  
Author(s):  
H. Wajcman ◽  
E. Girodon ◽  
D. Prom� ◽  
M.L. North ◽  
F. Plassa ◽  
...  
Keyword(s):  
Oxygen Affinity ◽  
High Oxygen ◽  
Germline Mosaicism ◽  
New Variant ◽  
High Oxygen Affinity

Unusual finding of high oxygen affinity haemoglobinopathy treated with phlebotomy: a rare but predictable union

2021 ◽  
pp. 103290
Author(s):  
Epifania Rita Testa ◽  
Adriana Masotti ◽  
Patrizia Valeri ◽  
Luciana Geremia ◽  
Valeria Brunetta ◽  
...  
Keyword(s):  
Oxygen Affinity ◽  
High Oxygen ◽  
High Oxygen Affinity ◽  
Unusual Finding

scholarly journals Haemoglobin Olympia {β Codon 20 (B2) G→A, Val→Met}: A Silent Haemoglobin Variant

2021 ◽  
Author(s):  
Abhay A Bhave ◽  
Lakshmi Iyer ◽  
Nawal Kazi ◽  
Manju Gorivale ◽  
Anita Nadkarni
Keyword(s):  
High Performance ◽  
Extended Family ◽  
Globin Gene ◽  
Oxygen Affinity ◽  
High Oxygen ◽  
Cerebral Vessel ◽  
Haemoglobin Variant ◽  
First Case ◽  
History Of ◽  
High Oxygen Affinity

High oxygen affinity haemoglobin variants are rare and often underdiagnosed in persistent erythrocytosis with no apparent aetiology. Here the author present a 29-year-old Indian male patient with a long-standing history of erythrocytosis which was incidentally detected. The proband had a prothrombotic family history of cerebral vessel stroke in his paternal grandfather at a young age and unexplained erythrocytosis in his father and brother. A review of his haemograms showed persistent high haemoglobin values. Routine tests did not reveal any specific aetiology and haemoglobin electrophoresis by High-Performance Liquid Chromatography (HPLC) showed absence of any abnormal peak or unstable haemoglobin. DNA sequencing of the β globin gene revealed heterozygosity for codon 20 {GTG→ATG, Valine (Val)→ Methionine (Met)} mutation confirming the presence of an electrophoretically silent Hb variant - Haemoglobin Olympia in him and his extended family members. This case study emphasises importance of this rare entity of high oxygen affinity haemoglobin variant as a differential diagnosis while screening for erythrocytosis. This is the first case report of Haemoglobin Olympia from India reported in the literature.

scholarly journals A Newly Characterized Hemoglobin Variant with a High Oxygen Affinity, Hb Fuchu-II, Presenting with Acute Myocardial Infarction

2016 ◽  
Vol 55 (3) ◽  
pp. 285-287
Author(s):  
Raku Son ◽  
Takakazu Higuchi ◽  
Atsushi Mizuno ◽  
Ryosuke Koyamada ◽  
Sadamu Okada ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Oxygen Affinity ◽  
High Oxygen ◽  
Hemoglobin Variant ◽  
High Oxygen Affinity

Novel High Oxygen Affinity Hemoglobin Variant in a Patient with Polycythemia: Hb Kennisis [β85(F1)Phe→Leu (TTT>TTG); HBB: c.258T>G]

Hemoglobin ◽  
2020 ◽  
Vol 44 (1) ◽  
pp. 10-12
Author(s):  
Ibrahim Al Nabhani ◽  
John C. Aneke ◽  
Madeleine Verhovsek ◽  
Barry Eng ◽  
Kevin H.M. Kuo ◽  
...  
Keyword(s):  
Oxygen Affinity ◽  
High Oxygen ◽  
Hemoglobin Variant ◽  
High Oxygen Affinity

scholarly journals Hemoglobin Crete (beta 129 ala leads to pro): a new high-affinity variant interacting with beta o -and delta beta o -thalassemia

Blood ◽  
1979 ◽  
Vol 54 (1) ◽  
pp. 54-63 ◽  
Author(s):  
A Maniatis ◽  
T Bousios ◽  
RL Nagel ◽  
T Balazs ◽  
Y Ueda ◽  
...  
Keyword(s):  
Cell Morphology ◽  
Clinical Picture ◽  
Oxygen Affinity ◽  
High Oxygen ◽  
Red Cell ◽  
High Affinity ◽  
Contact Sites ◽  
Erythroid Hyperplasia ◽  
Proline Substitution ◽  
High Oxygen Affinity

Abstract Hemoglobin Crete, beta129 (h7)ala leads to pro, is a new mutant hemoglobin (Hb) with high oxygen affinity that was discovered in a Greek family in various combinations with beta- and deltabeta- thalassemia. The propositus, who presented an unusual clinical picture of an “overcompensated” hemolytic state, with erythrocytosis, splenomegaly, abnormal red cell morphology, and marked erythroid hyperplasia, appeared doubly heterozygous for Hb Crete and deltabeta- thalassemia. His red cells contained 67% Hb Crete and 30% Hb F, and the combination of these two hemoglobins resulted in a blood P50O2 of 11.2 mm Hg. A brother with Hb Crete trait (38% Hb Crete, 56% Hb A, blood P50O2 23.0 mm Hg) did not have significant erythrocytosis. Purified Hb Crete was heat-unstable and exhibited a high oxygen affinity, and a normal Bohr effect. We postulate that the beta 129 proline substitution disrupts the H helix, perturbing nearby residues involved in alpha 1 beta 1 contact sites of the Hb tetramer.

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