Red blood cell phenotypes in the α<sup>+</sup> thalassaemias from early childhood to maturity

Williams, Thomas N.; Maitland, Kathryn; Ganczakowski, M; Peto, Tim; Clegg, J. B.; Weatherall, D. J.; Bowden, Donald Keith

doi:10.1046/j.1365-2141.1996.d01-1906.x

Cited by 42 publications

(41 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is in accordance with an earlier study reported that the -α 3.7 deletion at the heterozygous state has no effect, except on MCH values and this occurs only in childhood (Williams et al 1996).…”

Section: α-Thalassaemia In Tunisiasupporting

confidence: 94%

α-Thalassaemia in Tunisia: some epidemiological and molecular data

Siala

Ouali

Messaoud

et al. 2008

J Genet

View full text Add to dashboard Cite

Unlike the other haemoglobinopathies, few researches have been published concerning alpha-thalassaemia in Tunisia. The aim of the present work is to acquire further data concerning alpha-thalassaemia prevalence and molecular defects spectrum in Tunisia, by collecting and studying several kinds of samples carrying alpha-thalassaemia. The first survey conducted on 529 cord blood samples using cellulose acetate electrophoresis, have displayed the prevalence of 7.38% Hb Bart's carriers at birth. Molecular analyses were conducted by PCR and DNA sequencing on 20 families' cases from the above survey carrying the Hb Bart's at birth and on 10 Hb H diseased patients. The results showed six alpha-globin gene molecular defects and were responsible for alpha-thalassaemia: -alpha(3.7), - -(MedI), alpha(TSaudi), alpha(2)(cd23GAG->Stop), Hb Greone Hart: alpha(1)(119CCT->TCT) corresponding to 11 genotypes out of which two are responsible for Hb H disease (- -(Med)/-alpha(3.7)) and (alpha(TSaudi)alpha/alpha(TSaudi)alpha) and a newly described polymorphism: alpha+6C->G. The geographical repartition of alpha-thal carriers showed that the -alpha3.7 deletion is distributed all over the country, respectively the alpha(HphI) and alpha(TSaudi) seem to be more frequent in the central region of the northeast region. The haematological and clinical data showed a moderate phenotype with a late age of diagnosis for Hb H disease. This work had permitted, in addition to an overview on alpha-thalassaemia in the country, the optimization of protocols for alpha-thalassaemia detection in our lab, allowing further investigations concerning phenotype-genotype correlation in sickle cell disease or beta-thalassaemia.

show abstract

Section: α-Thalassaemia In Tunisiasupporting

confidence: 94%

α-Thalassaemia in Tunisia: some epidemiological and molecular data

Siala

Ouali

Messaoud

et al. 2008

J Genet

View full text Add to dashboard Cite

show abstract

“…Although admission hemoglobin concentrations were similar between genotypic groups (Table 3), the trend toward increasing hemoglobin values across the groups is noteworthy, given that heterozygous and homozygous ␣ ϩ thalassemia are associated with anemia at steady state. 11 We found no effect of ␣ ϩ thalassemia on admission parasite density.…”

Section: Resultsmentioning

confidence: 50%

Both heterozygous and homozygous α+ thalassemias protect against severe and fatal Plasmodium falciparum malaria on the coast of Kenya

Williams

Wambua

Uyoga

et al. 2005

Blood

168

129

View full text Add to dashboard Cite

Although the ␣ ؉ thalassemias almost certainly confer protection against death from malaria, this has not been formally documented. We have conducted a study involving 655 case patients with rigorously defined severe malaria and 648 controls, frequency matched on area of residence and ethnic group. The prevalence of both heterozygous and homozygous ␣ ؉ thalassemia was reduced in both case patients with severe malaria (ad-

show abstract

“…Routine tests can be unreliable; for example, microcytosis is a poor indicator in populations where hemoglobinopathies are common 1,2 and acute malaria can result in both anemia 3 and elevated serum ferritin concentrations. 4,5 The transmembrane iron transport protein transferrin receptor (CD71) is a dimeric protein consisting of two identical 95-kD subunits.…”

mentioning

confidence: 99%

Reduced soluble transferrin receptor concentrations in acute malaria in Vanuatu.

Williams

Maitland²,

Rees³

et al. 1999

The American Journal of Tropical Medicine and Hygiene

View full text Add to dashboard Cite

Abstract. Soluble transferrin receptor (sTfR) concentration is a sensitive index of iron deficiency when used in conjunction with ferritin measurements in adults. One advantage of this assay is that unlike ferritin it does not appear to be affected by a range of infectious and inflammatory conditions or by pregnancy, rendering it a promising adjunct to the diagnosis of iron deficiency in tropical populations. We have measured plasma sTfR concentrations in a group of malaria patients (n ϭ 21) and asymptomatic (18) and aparasitemic (76) controls in Vanuatu. Plasma sTfR concentration was significantly reduced in individuals with acute malaria (P ϭ 0.003). While this observation provides evidence that erythropoeitic suppression may be an important etiologic component in malarial anemia, it also suggests that malaria may be a confounding factor when interpreting sTfR concentrations in such populations. The role of sTfR in the diagnosis of iron deficiency in tropical populations remains to be established.The diagnosis of iron deficiency can be difficult in tropical communities. Routine tests can be unreliable; for example, microcytosis is a poor indicator in populations where hemoglobinopathies are common 1,2 and acute malaria can result in both anemia 3 and elevated serum ferritin concentrations. 4,5 The transmembrane iron transport protein transferrin receptor (CD71) is a dimeric protein consisting of two identical 95-kD subunits. During red blood cell maturation, membrane transferrin receptor is degraded by endosomal digestion and an 85-kD fragment, soluble transferrin receptor (sTfR), is released into the circulation. 6 Plasma levels can be measured using a sensitive ELISA method. It has been estimated that 80% of circulating sTfR originates from developing red blood cells. The STfR concentration is pathologically increased in the presence of tissue iron deficiency, 7,8 and has been shown to be a sensitive index of this condition when interpreted in conjunction with ferritin measurements in adults. 7,8 Unlike ferritin, sTfR is not affected by a range of infections, inflammatory conditions or by pregnancy 9,10 and might thus be a useful tool in the assessment of iron status in tropical populations. We have investigated this possibility by measuring both sTfR and ferritin concentrations in malaria patients and control subjects living in Vanuatu.

show abstract

Red blood cell phenotypes in the α⁺ thalassaemias from early childhood to maturity

Cited by 42 publications

References 12 publications

α-Thalassaemia in Tunisia: some epidemiological and molecular data

α-Thalassaemia in Tunisia: some epidemiological and molecular data

Both heterozygous and homozygous α+ thalassemias protect against severe and fatal Plasmodium falciparum malaria on the coast of Kenya

Reduced soluble transferrin receptor concentrations in acute malaria in Vanuatu.

Contact Info

Product

Resources

About

Red blood cell phenotypes in the α+ thalassaemias from early childhood to maturity

Cited by 42 publications

References 12 publications

α-Thalassaemia in Tunisia: some epidemiological and molecular data

α-Thalassaemia in Tunisia: some epidemiological and molecular data

Both heterozygous and homozygous α+ thalassemias protect against severe and fatal Plasmodium falciparum malaria on the coast of Kenya

Reduced soluble transferrin receptor concentrations in acute malaria in Vanuatu.

Contact Info

Product

Resources

About

Red blood cell phenotypes in the α⁺ thalassaemias from early childhood to maturity