Molecular analysis and association with clinical and laboratory manifestations in children with sickle cell anemia

Abstract

ObjectivesTo analyze the frequency of βS-globin haplotypes and alpha-thalassemia, and their influence on clinical manifestations and the hematological profile of children with sickle cell anemia.MethodThe frequency of βS-globin haplotypes and alpha-thalassemia and any association with clinical and laboratorial manifestations were determined in 117 sickle cell anemia children aged 3–71 months. The confirmation of hemoglobin SS and determination of the haplotypes were achieved by polymerase chain reaction-restriction fragment length polymorphism, and alpha-thalassemia genotyping was by multiplex polymerase chain reaction (single-tube multiplex-polymerase chain reaction).ResultsThe genotype distribution of haplotypes was 43 (36.7%) Central African Republic/Benin, 41 (35.0%) Central African Republic/Central African Republic, 20 (17.0%) Rare/atypical, and 13 (11.1%) Benin/Benin. The frequency of the α3.7 deletion was 1.71% as homozygous (−α3.7/−α3.7) and 11.9% as heterozygous (−α3.7/αα). The only significant association in respect to haplotypes was related to the mean corpuscular volume. The presence of alpha-thalassemia was significantly associated to decreases in mean corpuscular volume, mean corpuscular hemoglobin and reticulocyte count and to an increase in the red blood cell count. There were no significant associations of βS-globin haplotypes and alpha-thalassemia with clinical manifestations.ConclusionsIn the study population, the frequency of alpha-thalassemia was similar to published data in Brazil with the Central African Republic haplotype being the most common, followed by the Benin haplotype. βS-globin haplotypes and interaction between alpha-thalassemia and sickle cell anemia did not influence fetal hemoglobin concentrations or the number of clinical manifestations.

Influence of alpha thalassemia on clinical and laboratory parameters among nigerian children with sickle cell anemia

“…The observed hematological profile of patients with α‐thal in this study has been previously described . The increased Hb and red blood cell count are due to the decrease in the intracellular concentration of HbS, and number of dense red blood cells .…”

“…The prevalence of alpha thalassemia among patients in this study (41%) is comparable to between 37% and 46% earlier described among mixed populations of SCA patients from France and West Africa . This is however higher than the 13%‐28% described among patients in the Americas . These observations may be due to regional differences.…”

Beta-Globin Haplotypes and Alpha-Thalassemia 3.7 kb Deletion in Sickle Cell Disease Patients From the Occidental Brazilian Amazon

“…Finally, few studies have compared biochemical and hematological parameters across SCD individuals of different β-globin and α-thalassemia molecular backgrounds. Here we describe the β-globin and α-thalassemia genetic profile of a population sample of individuals affected by sickle cell and hemoglobin SC disease from the Brazilian Amazon, presented and discussed in the context of a comprehensive hematological and biochemical profile [20][21][22][23].…”

Comment on “Molecular analysis and association with clinical and laboratory manifestations in children with sickle cell anemia”

“…In this issue of the Revista Brasileira de Hematologia e Hemoterapia , Camilo-Araújo present an analysis of the frequency of βS-globin haplotypes and alpha-thalassemia, and their influence on clinical manifestations and the hematological profile of children with sickle cell anemia. 41 …”