Learn more about sickle cell anemia, the most common inherited blood disorder in the US, at an NIH web site or the Sickle Cell Disease Association of America web site.
Here's a NY Times story about recently approved gene therapy (for those interested in science writing, the author Gina Kolata is a great writer who tells engaging stories while reliably getting the science right, and she has several books out). Gene therapy is an important step forward, but sadly, as this story covers, the current cost of gene therapy makes it unavailable to many patients, and as these stories cover, gene therapy patients have faced some challenges to date.
Here's an earlier 22-minute radio story about the first US patient whose bone marrow cells' genes were edited using CRISPR.
Get an idea of what else is being tried right now toward cures and toward treatments for symptoms by seeing current clinical trials.