Fighting sickle cell with gene editing
Doctors in the U.S. are using CRISPR, the pioneering gene-editing technique, in a landmark effort to treat a debilitating and often fatal genetic disorder. The experimental treatment—a first in the U.S.—is for sickle-cell disease, a disorder that affects 100,000 Americans and causes problems with a protein called hemoglobin. The defective hemoglobin makes red blood cells hard and sticky, preventing them from carrying enough oxygen around the body. Sickle-cell sufferers—most of whom are black—can experience intense pain, organ damage, and blindness; many don’t live beyond their 40s. For the CRISPR treatment, scientists extract young cells from the patient’s bone marrow and modify them to produce fetal hemoglobin, typically made only by fetuses in the womb. Patients undergo chemotherapy to kill off cells carrying the genetic defect and then have the CRISPRedited cells reintroduced into their body. Doctors at the Sarah Cannon Research Institute in Nashville have already completed treatment on the first patient, 34-year-old Victoria Gray. They hope to enlist 44 others, in the U.S., Canada, and Europe. The experiment is at a very early stage: It’ll take several months before doctors can tell whether the new cells are producing the hemoglobin and longer still to determine if the patient’s health has improved. But that’s not a problem for Gray. “This gives me hope,” she tells NPR .org, “[even] if it gives me nothing else.”