Impact of HBS1L-MYB Gene Single Nucleotide Polymorphisms on Fetal Hemoglobin Expression in Moroccan Sickle Cell...

Fetal hemoglobin (HbF) expression is a key modifier of sickle cell disease (SCD) severity, and the HBS1L-MYB intergenic region is a critical regulator of HbF levels. However, the impact of HBS1L-MYB polymorphisms and HbF levels in Moroccan populations remains underexplored. This work aimed to investigate the population-specific distribution of three HBS1L-MYB polymorphisms (rs28384513, rs4895441, and rs9402686) in 160 Moroccan children, including 80 with SCD (1-15 years) and 80 healthy controls. The SCD group was further divided into two groups based on HbF levels (< 15% and ≥ 15%). DNA genotyping was performed using PCR-RFLP analysis. Retrospective demographic and hematological data were collected to assess the association between these SNPs and HbF levels. Significant associations were found between rs28384513 and red blood cell count (p = 0.009), rs4895441 and mean corpuscular haemoglobin (p = 0.02), and rs9402686 with both hemoglobin (p = 0.001) and HbF levels (p = 0.003), confirming the significant influence of this SNP on HbF expression. These findings highlight the beneficial effect of rs9402686 on HbF expression. Investigating the large and genetically diverse cohort of Moroccan SCD will be essential for a deeper understanding of the molecular mechanisms underlying these polymorphisms and for identifying new disease modifier genes.