𝛼-Thalassaemia in Tunisia: some epidemiological and molecular data

[摘要] Unlike the other haemoglobinopathies, few researches have been published concerning 𝛼-thalassaemia in Tunisia. The aim of the present work is to acquire further data concerning 𝛼-thalassaemia prevalence and molecular defects spectrum in Tunisia, by collecting and studying several kinds of samples carrying 𝛼-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 𝛼-globin gene molecular defects and were responsible for 𝛼-thalassaemia: -𝛼3.7, - -MedI, 𝛼TSaudi, 𝛼cd23GAG o Stop2, Hb Greone Hart: 𝛼119CCT o TCT1 corresponding to 11 genotypes out of which two are responsible for Hb H disease (--Med/$-$𝛼3.7) and (𝛼TSaudi𝛼/𝛼TSaudi𝛼) and a newly described polymorphism: 𝛼+6 → G. The geographical repartition of 𝛼-thal carriers showed that the $-$𝛼3.7 deletion is distributed all over the country, respectively the 𝛼HphI and 𝛼TSaudi 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 𝛼-thalassaemia in the country, the optimization of protocols for 𝛼-thalassaemia detection in our lab, allowing further investigations concerning phenotype–genotype correlation in sickle cell disease or 𝛽-thalassaemia.

[学科分类] 生物科学（综合）

[关键词] ð›¼-thalassaemia;Hb Bart’s;Hb H disease;molecular defects;Tunisia.