Gene editing shows promise for sickle cell disease

Scientists are seeing promising early results from the first studies testing gene editing for painful, inherited blood disorders that plague millions worldwide, especially Black people.

Doctors hope the one-time treatment, which involves permanently altering DNA in blood cells with a tool called CRISPR, may treat and possibly cure sickle cell disease and beta thalassemia.

Partial results were presented Saturday at an American Society of Hematology conference and some were published by the New England Journal of Medicine.

Doctors described 10 patients who are at least several months removed from treatment. All no longer need regular blood transfusions and are free from pain that plagued their lives before.

Victoria Gray was the first patient in the sickle cell study.

“I had aching pains, sharp pains, burning pains, you name it. That’s all I’ve known my entire life,” said Gray, 35, of Forest, Mississippi. “I was hurting everywhere my blood flowed.”

Since her treatment a year ago, Gray has weaned herself from pain medications she depended on.

Sickle cell affects millions, mostly Black people. Beta thalassemia strikes about one in 100,000 people. The only cure now is a bone marrow transplant from a closely matched donor without the disease like a sibling, which most people don’t have.

Both diseases involve mutations in a gene for hemoglobin, the substance in red blood cells that carries oxygen throughout the body.

In sickle cell, defective hemoglobin leads to deformed, crescent-shaped blood cells that don’t carry oxygen well. They can stick together and clog small vessels, causing pain, organ damage and strokes.

Those with beta thalassemia don’t have enough normal hemoglobin, and suffer anemia, fatigue, shortness of breath and other symptoms. Severe cases require transfusions every two to five weeks.

The treatment studied attacks the problem at its genetic roots.

In the womb, fetuses make a special type of hemoglobin. After birth, when babies breathe on their own, a gene is activated that instructs cells to switch and make an adult form of hemoglobin instead. The adult hemoglobin is what’s defective in people with one of these diseases. The CRISPR editing aims to cut out the switching gene.