Investigating alpha-globin structural variants: a retrospective review of 135,000 Brazilian individuals

Kimura, Elza; Oliveira, De; Jorge, Susan E.; Ribeiro, Daniele Silva; Zaccariotto, Tânia Regina; Santos, Magnun Nueldo Nunes; Almeida, Vanessa; Albuquerque, Dulcinéia Martins; Costa, Fernando Ferreira; Sonati, María de Fátima

doi:10.1016/j.bjhh.2015.01.005

Cited by 3 publications

(3 citation statements)

References 34 publications

(34 reference statements)

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“…In blood banks from Brazil, although there are rigid and regulated techniques, it is still a great problem to enhance the identification of all types and causes of anemia. is is due to the need to use different methodologies in the differential diagnosis [16]. However, several studies have shown good results using hematological parameters of the conventional hemogram [32,33].…”

Section: Resultsmentioning

confidence: 99%

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Deletional Alpha-Thalassemia Alleles in Amazon Blood Donors

Anselmo

Ferreira

Mota

et al. 2020

Advances in Hematology

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Alpha-thalassemia is highly prevalent in the plural society of Brazil and is a public health problem. There is limited knowledge on its accurate frequency and distribution in the Amazon region. Knowing the frequency of thalassemia and the prevalence of responsible mutations is, therefore, an important step in the understanding and control program. Hematological and molecular data, in addition to serum iron and serum ferritin, from 989 unrelated first-time blood donors from Amazonas Hemotherapy and Hematology Foundation (FHEMOAM) were collected. In this study, the subjects were screened for −α3.7/4.2/20.5, −SEA, −FIL, and −MED deletions. Alpha-thalassemia screening was carried out between 2016 and 2017 among 714 (72.1%) male and 275 (27.9%) female donors. The aims of this analysis were to describe the distribution of various alpha-thalassemia alleles by gender, along with their genotypic interactions, and to illustrate the hematological changes associated with each phenotype. Amongst the patients, 5.35% (n = 53) were diagnosed with deletion –α−3.7 and only one donor with α−4.2 deletion. From the individuals with –α−3.7, 85.8% (n = 46) were heterozygous and 14.20% (n = 7) were homozygous. The frequency of the –α−3.7 deletion was higher in male (5.89%) than in female (4.0%). There is no significant difference in the distribution of –α−3.7 by gender (p=0.217). The –α20.5, −SEA, and −MED deletions were not found. All subjects were analyzed for serum iron and serum ferritin, with 1.04% being iron deficient (n = 5) and none with very high levels of stored iron (>220 µg/dL). Alpha-thalassemia-23.7kb deletion was the most common allele detected in Manaus blood donors, which is a consistent result, once it is the most common type of α-thalassemia found throughout the world. As expected, the mean of hematological data was significantly lower in alpha-thalassemia carriers (p<0.001), mainly homozygous genotype. Leukocytes and platelet count did not differ significantly. Due to the small number of individuals with iron deficiency found among blood donors, the differential diagnosis between the two types of anemia was not possible, even because minor changes were found among hematological parameters with iron deficiency and α-thalassemia. Despite this, the study showed the values of hematological parameters, especially MCV and MCH, are lower in donors with iron deficiency, especially when associated with α-thalassemia, and therefore, it may be useful to discriminate different types of microcytic anaemia. In conclusion, we believed screening for thalassemia trait should be included as part of a standard blood testing before blood donation. It should be noted that this was the first study to perform the screening for alpha deletions in blood donors from the Manaus region, and further studies are required to look at the effects of donated thalassemic blood.

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Section: Resultsmentioning

confidence: 99%

“…In silent thalassemic state, carriers are essentially asymptomatic and the complete blood count, hemoglobin electrophoresis, and peripheral smear are usually normal. Slight hypochromia and microcytosis may be evident by microscopic evaluation [13][14][15][16][17].…”

Section: Introductionmentioning

confidence: 99%

Deletional Alpha-Thalassemia Alleles in Amazon Blood Donors

Anselmo

Ferreira

Mota

et al. 2020

Advances in Hematology

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“…The Hb variants resulting from changes in the alpha gene (HBA) are less frequent, and can be confused with other Hb variants during laboratory diagnosis. The most prevalent variant in Brazil is Hb Hasharon, followed by Hb Stanleyville II and Hb J-Rovigo (Kimura et al, 2015).…”

Section: Introductionmentioning

confidence: 99%

Hemoglobin (Hb) Val de Marne (Hb Footscray) in Brazil: the first case report

et al. 2016

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ABSTRACT. Hemoglobin (Hb) variants involving alpha-chains are less common in the global population than Hb variants resulting from beta-chain alterations. Generally, alpha-chain Hb variants are caused by point mutations affecting alpha-1 and/or alpha-2 genes of the alpha-globin cluster (HBA1 and HBA2). In Brazil, the most prevalent alpha-chain Hb variant is Hb Hasharon. In this study, we present the first case of an Hb Val de Marne variant in the Americas, specifically in Brazil.

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