Sickle Cell Disease in Sub-Saharan Africa: Is CRISPR-Cas9 the Breakthrough We’ve Been Waiting for?

Abstract

Sickle cell disease, which results from a single nucleotide substitution in the beta-globin gene (HBB) is recognized as a significant global health concern. Approximately 7.74 million people worldwide were living with sickle cell disease in 2021. Sub-Saharan Africa carries the highest disease burden, with mortality rates ranging from 50 to 90% among affected children within the first five years of life. Current FDA-approved therapies (hydroxyurea and glutamine) offer symptomatic relief but are not sufficient to fully prevent the disease from progressing into a chronic condition. Allogeneic hematopoietic stem cell transplantation is the only curative treatment but is limited by donor availability and immunological complications. Advances in gene-editing technologies, particularly CRISPR-Cas9, present promising solutions by enabling precise genetic modifications. CRISPR-Cas9 is employed to treat sickle cell disease either through direct correction of the causative mutation in the HBB gene or by inducing fetal haemoglobin production. The FDA’s recent approval of CASGEVY™ marks a historic milestone as the first CRISPR-based therapy for sickle cell disease. CASGEVY™, which induces fetal haemoglobin production, showed 93.5% efficacy in preventing severe vaso-occlusive crises in sickle cell disease patients, with no graft failures or rejections reported. Despite its promise, challenges remain, including technical barriers such as delivery strategies, off-target effects, and unintended genetic alterations, as well as ethical, societal, and regulatory concerns. In Sub-Saharan Africa, inadequate healthcare infrastructure, high treatment costs, and limited public awareness further hinder widespread adoption. To harness CRISPR’s potential, Africa must invest in advanced genomic laboratories, interdisciplinary training for healthcare professionals, and robust educational programs in molecular biology and biotechnology. Regional and international collaborations are essential to overcome these barriers, streamline regulatory processes, and foster public acceptance as CRISPR-Cas9 holds transformative potential for addressing sickle cell disease in Africa, offering a pathway toward reducing mortality and improving quality of life for affected populations.