First approved CRISPR trial on sickle cell disease treatment

Sickle cell disease (SCD) is an inherited red blood cell disorder that affects approximately 100,000 Americans per year, rendering it the most common genetic disease in the United States. The structural defect in SCD is caused by a point mutation in haemoglobin (HbG). A substitution from glutamic acid to valine results in a single nucleotide change (A to T) in the β-globin gene. The intermolecular interactions induced by valine form sickle haemoglobin (HbS), termed deoxyhaemoglobin S. Deoxyhaemoglobin S causes HbS tetramers to polymerise at low oxygen levels. The sickle-shaped red blood cells are unable to pass through microvessels, resulting in impaired blood flow and vascular occlusion. Due to the clinical heterogeneity of SCD, it is difficult to predict the onset of disease occurrence in patients who are affected. There is an urgent need for improvements in our ability to predict SCD events, and for advances in therapeutic solutions to correct the causative mutation in patients with SCD