Research Article Clinical and hematological parameter alterations found in sickle cell anemia heterozygotes in Brazil

Abstract

Heterozygosis for the hemoglobin S allele is a relatively common condition that is clinically benign and rarely presents clinical or hematological manifestations. Although rare, symptoms have been reported in these patients. We examined clinical manifestations and laboratory findings in HbAS individuals that could be related to the β S haplotypes: in 31 heterozygotes, with a predominance of females and young adults, and 43 AA homozygotes considered as a control group from samples previously stored in our laboratory. We performed clinical, biochemical and hematological tests, as well as genotyping by PCR-RFLP for the identification of β S haplotypes. Bantu and Benin haplotypes were equally frequent (n= 7, each) and 17 individuals had shown atypical haplotypes. We observed hematological alterations (e.g. ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 18 (1): gmr18109 L.X. Souza et al. 2 mean corpuscular volume levels) that suggest microcytic and hypochromic anemia; however, we did not find iron deficiency anemia or thalassemia. In the clinical examination, the heterozygote individuals reported pain, especially in the upper and lower limbs and joints, as the most frequent complaint. HbS heterozygotes, different from literature reports, had a significantly greater frequency of anemia-related parameters when compared to normal homozygotes.

Biomarkers of clinical severity in treated and untreated sickle cell disease: a comparison by genotypes of a single center cohort and African Americans in the NHANES study

“…Less frequent genotypes include compound heterozygous associations of HbS and HbC (Hb SC), or HbS and β‐thalassaemia (Hb Sβ‐thalassaemia) 5 . Broadly speaking, SCD patients can be categorised into mild (Hb SC and Hb Sβ + ‐thalassaemia) or severe (Hb SS and Hb Sβ 0 ‐thalassaemia) β‐globin groups, 6 , 7 but these genotype groups do not completely account for the clinical course of the disease 8 , 9 . Even within these groups, clinical severity varies remarkably, ranging from a barely perceptible clinical disease course to severely debilitating illness resulting in a host of complications 1,3 .…”

“…5 Broadly speaking, SCD patients can be categorised into mild (Hb SC and Hb Sb + -thalassaemia) or severe (Hb SS and Hb Sb 0 -thalassaemia) b-globin groups, 6,7 but these genotype groups do not completely account for the clinical course of the disease. 8,9 Even within these groups, clinical severity varies remarkably, ranging from a barely perceptible clinical disease course to severely debilitating illness resulting in a host of complications. 1,3 Genetic, epigenetic, environmental and therapeutic factors contribute to this phenotypic variability.…”