Gene therapy lets a French teen dodge sickle cell disease

This image shows the red blood cells of someone with sickle cell disease. (Janice Haney Carr/CDC/Sickle Cell Foundation of Georgia via AP)

Researchers say a French teen who was given gene therapy for sickle cell disease more than two years ago now has enough properly working red blood cells to dodge the effects of the disorder.

The teen was the first in the world to get the treatment for sickle cell, which affects 90,000 Americans, mostly blacks. It's caused by a defective gene for hemoglobin, the stuff in red blood cells that carries oxygen. The cells curl up and clog small blood vessels, causing pain and serious problems.

The boy was given a gene to prevent the sickling, and now half of his red cells work normally. Three similar gene therapy studies are underway in the U.S.

The case is detailed in Thursday's New England Journal of Medicine.