Sickle cell disease (SCD) is the most common deadly genetic disorder, affecting more than 300,000 newborns worldwide each year. It leads to chronic pain, organ failure, and early death in patients. A team led by researchers at the Broad Institute of MIT and Harvard and St. Jude Children’s Research Hospital has now demonstrated a base editing approach that efficiently corrects the mutation underlying SCD in patient blood stem cells and in mice. This gene editing treatment rescued the disease symptoms in animal models, enabling the long-lasting production of healthy blood cells.
The root of SCD is two mutated copies of the hemoglobin gene, HBB, which cause red blood cells to transform from a circular disc into a sickle shape — setting off a chain of events leading to organ damage, recurrent pain, and early mortality. In this study, the researchers used a molecular technology called base editing to directly convert a single letter of pathogenic DNA into a harmless genetic variant of HBB in human blood-producing cells and in a mouse model of SCD.