Sickle cell disease in Sub-Saharan Africa: Molecular mechanisms underlying episodic crises, current and emerging therapeutic strategies in treatment

Abstract

Sickle cell disease (SCD) is a haematological disease that affects multiple organs, thus eliciting episodes of chronic pain, acute anaemia and infection, due to a single nucleotide mutation in the β-globin gene, which results in the substitution of a glutamic acid residue in place of valine on the β-globin chain of the resultant haemoglobin protein molecule, the sickle haemoglobin (HbS). SCD is a major cause of morbidity and mortality characterized by episodes of vaso-occlusivecrises, pain syndromes and end organ dysfunctions. Its global prevalence is highest in Sub-Saharan Africa with 75% of global births living in this region, of which Nigeria has the highest number of SCD patients with about 100.000 births each year. The burden of SCD in the sub-Saharan region of Africa is enormous. Emotional, financial and total healthcare costs are monumental. An understanding of the mechanism underlying the vaso-occlusive crises, pain syndromes, inflammatoryconditions and other sequelae of SCD appears to be essential in providing more rational treatments. The present review discuses the prevalence of SCD in Africa, molecular mechanisms underlying SCD episodic crises including vaso-occlusive syndrome, anaemia and infection. Current available treatments modalities in Sub-Saharan Africa and possible new treatment methods that cure SCD are re-examined in light of these mechanisms.