One year ago, Victoria Gray became the first person in the U.S. to receive a revolutionary treatment for sickle cell disease (SCD). SCD is a genetic disorder in which the red blood cells—the cells that carry oxygen throughout the body—can become shaped like a crescent, or “sickle.”
These misshaped cells build up in blood vessels, causing episodes of significant pain and damaging organs and tissues. People with SCD have to avoid strenuous activities and high or low temperatures because these can trigger their cells to become deformed.
SCD affects about 20 million people worldwide and 100,000 people in the U.S. In the U.S., about 1 out of every 365 African Americans and one out of every 16,300 Hispanic Americans is born with SCD. Despite its prevalence, SCD research has been underfunded. And, it is more difficult to get treatment compared to similar diseases that are more likely to affect white people. Recent initiatives in the research community are now working to correct that neglect.
With access to proper care, people can live into their 40s or 50s. Without it, an estimated 50–90% of people with SCD die in childhood. The only known cure is a bone marrow transplant, but those are risky and require a matching donor. Patients who are not good candidates for a transplant are treated with periodic blood transfusions, pain management and antibiotics.
Gray’s treatment was similar to a bone marrow transplant, but instead of finding a donor, researchers removed some of her own marrow and genetically modified it. They used a relatively new technique called CRISPR. CRISPR, which was discovered through National Institutes of Health-funded research, is more precise and less expensive than earlier gene-editing techniques.
A key protein, called hemoglobin, is faulty in the red blood cells in SCD patients. This is the reason the red blood cells change shape. The researchers modified Gray’s bone marrow to produce a different kind of hemoglobin, called fetal hemoglobin, which the body usually stops making shortly after you are born. Fetal hemoglobin does not contain the SCD mutation so it does not cause cells to become sickle shaped.
A year after her treatment, Gray’s body is still making enough fetal hemoglobin that her doctors are cautiously optimistic. She has been able to attend her son’s football games in-person and is starting to look forward to being there when her children marry and have children of their own. These are simple milestones many of us take for granted.
Read more about Gray’s journey and the recent advances in the fight against SCD in this coverage from National Public Radio.