Co-Inheritance of alpha-thalassemia and sickle cell disease in a cohort of Angolan pediatric patients

© Springer Nature B.V. 2020The aim of this study was to explore the association between alpha-thalassemia, fetal hemoglobin, hematological indices, and clinical adverse events in Angolan sickle cell disease pediatric patients. A total of 200 sickle cell disease (SCD) children were sampled in Luanda and Caxito. A venous blood sample was collected and used for hematological analyses, fetal hemoglobin quantifcation, and genotyping of 3.7 kb alpha-thalassemia deletion by GAP-PCR. The frequency of the 3.7 kb alpha-thalassemia deletion in homozygosity was 12.5% and in heterozygosity was 55.0%. An increase in alpha-thalassemia frequency was observed in children older than 5 years old (11.7% vs. 13.00%). Furthermore, 3.7 kb alpha-thalassemia deletion homozygotes had a signifcantly higher age of the frst manifestation, lower number of blood transfusions by year, higher hemoglobin, lower mean corpuscular volume, mean corpuscular hemoglobin, and lower hemolytic rate observed by a lower number of reticulocytes count. There were no diferences in fetal hemoglobin between the three genotypes. Moreover, the number of stroke events, osteomyelitis, splenomegaly, splenectomy, and hepatomegaly were lower when alpha-thalassemia was co-inherited. For the frst time in Angolan population, the efect of alpha-thalassemia deletion in sickle cell disease was analyzed and results reinforce that this trait infuences the hematological and clinical aspects and produces a milder phenotype.This work was supported by the Fundação Para a Ciência e Tecnologia I.P./Aga Khan Development Network Project Number 330842553.