Fetal hemoglobin gene expression in patients with sickle cell disease in North Central Nigeria

BACKGROUND: Fetal hemoglobin (HbF) plays a dominant role in ameliorating morbidity and mortality associated with sickle cell disease (SCD). OBJECTIVE: This study evaluated the distribution pattern of HbF and total Hb concentration among 75 participants with homozygous sickle cell trait (HbSHbS) as test cases and 71 with homozygous normal trait (HbAHbA) as controls. MATERIALS AND METHODS: Ethylenediaminetetraacetic acid-anticoagulated blood samples were collected from all participants. They were tested for HbF and HbA fractions using high-performance liquid chromatography, while total Hb concentration was determined by cynomethemoglobin technique. RESULTS: Participants with HbSHbS genotype showed mean ± standard error of mean (SEM) of HbF levels of 6.5 ± 0.8%, HbA1 showed mean ± SEM of 2.6 ± 0.3%, and HbA2 showed mean ± SEM of 4.9 ± 0.1%. Those with HbAHbA (control participants) genotype showed mean ± SEM of HbF levels of 0.5 ± 0.04%, HbA1 showed mean ± SEM of 87.3 ± 0.4%, and HbA2 showed mean ± SEM of 3.2 ± 0.1%, while the mean ± SEM Hb concentration of test cases was 6.5 ± 0.16 g/dl and that of controls was 12.32 ± 0.13 g/dl. The total Hb concentration of sickle cell patients was significantly lower than that of nonsickle cell patients. There was a positive correlation of Hb concentration (g/dl) with HbSHbS gene expression. CONCLUSION: Findings from this study revealed that the lesser episodes of sickle cell crisis, the lower the HbF expression and higher the total Hb concentration. Hence, it is recommended that the determination of HbF, HbA1, and HbA2 levels be considered in conjunction with other routine complete blood count and hematology tests in the diagnosis and clinical management of SCD.