Haemoglobin E and alpha-Thalassaemia.

Wasi, P; Sookanek, Munsit; Pootrakul, S.; Na-Nakorn, S; Suingdumrong, A

doi:10.1136/bmj.4.5570.29

Cited by 32 publications

(14 citation statements)

References 22 publications

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“…This thalassemia syndrome is characterized by the presence of HbA, HbE, and Hb Bart's, and results from the interaction of the genotype of HbH disease (see Higgs 2012;Vichinsky 2012) with heterozygous HbE (Wasi et al 1967;Thonglairuam et al 1989). Two common subtypes of HbAE Bart's disease have been observed: a þ thalassemia/a 0 thalassemia-A/E and a 0 thalassemia/Hb Constant Spring-A/E.…”

Section: Hbae Bart's Diseasementioning

confidence: 99%

The Hemoglobin E Thalassemias

Fucharoen¹,

Weatherall²

2012

Cold Spring Harbor Perspectives in Medicine

183

114

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Hemoglobin E (HbE) is an extremely common structural hemoglobin variant that occurs at high frequencies throughout many Asian countries. It is a b-hemoglobin variant, which is produced at a slightly reduced rate and hence has the phenotype of a mild form of b thalassemia. Its interactions with different forms of a thalassemia result in a wide variety of clinical disorders, whereas its coinheritance with b thalassemia, a condition called hemoglobin E b thalassemia, is by far the most common severe form of b thalassemia in Asia and, globally, comprises approximately 50% of the clinically severe b-thalassemia disorders.

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Section: Hbae Bart's Diseasementioning

confidence: 99%

The Hemoglobin E Thalassemias

Fucharoen¹,

Weatherall²

2012

Cold Spring Harbor Perspectives in Medicine

183

114

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“…Although the incidence of Hb H disease in Blacks is admittedly low (40)(41)(42), the apparent rarity of the combined defect may also be a result of the lack of a readily available means of detection, since Hb H is not always present in measurable amounts. Although other patients with a ,-chain abnormality and a suspected Hb H genotype, but without 4A tetramers have been described (1,5,14,(43)(44)(45)(46), direct demonstration of the a-globin gene defect has not previously been possible.…”

Section: Methodsmentioning

confidence: 99%

Modification of Hemoglobin H Disease by Sickle Trait

Matthay¹,

Mentzer²,

Dozy³

et al. 1979

J. Clin. Invest.

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A B S T R A C T The rarity of hemoglobin (Hb) H disease in combination with sickle trait may be due in part to the absence ofactual Hb H in individuals who, nonetheless, have inherited the deletion of three a-globin genes. We describe here a boy with persistent microcytic, hypochromic anemia despite adequate iron stores, who exhibited splenomegaly with a normal reticulocyte count and only rare inclusions in circulating erythrocytes. Starch gel electrophoresis and isoelectric focusing at age 5 yr showed 21% Hb S, persistent Hb Bart's, but no Hb H. Recticulocyte a/non-a globin chain synthesis ratio was 0.58 at age 5. The mother (Asian) had laboratory evidence of a-thalassemia trait and the father (Black) had sickle trait. The nature of a-thalassemia in this patient was investigated both by liquid hybridization and by the Southern method of gene mapping, in which DNA is digested with restriction endonucleases and the DNA fragments that contained the a-globin structural gene identified by hybridization with complementary DNA. The patient had only one a-globin structural gene, located in a DNA fragment shorter than that found in normal or a-thalassemia trait individuals, but similar to that present in other patients with Hb H disease. Morphologic studies of bone marrow by light and electron microscopy revealed erythroid hyperplasia with inclusions in polychromatic and orthochromatic erythroblasts, suggesting early precipitation of an unstable hemoglobin. The lack of demonstrable Hb H may be the result of both diminished amounts of(A available for Hb H formation (since one 8-globin gene is (3s) and the greater affinity of a-chains for (3A than 8s-globin chains leading to the formation of relatively more Hb A than Hb S. The pres-

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“…5,21 Because it is an autosomal recessive disorder, when both parents have two α-globin gene deletions in cis on chromosome 16 (each parent, --/αα), any offspring will have a 25% chance of having BHFS. In BHFS, haemoglobin tetramers of only gamma chains (γ 4 ) is ineffective in erythropoiesis and oxygen delivery to tissues.…”

Section: Discussionmentioning

confidence: 99%