A common genetic blood disorder has been corrected in cultured stem cells by using a cutting-edge genome-editing technique.

The disorder β-thalassaemia is characterized by reduced levels of haemoglobin due to mutations in the gene for β-globin (HBB). Yuet Kan and his colleagues at the University of California, San Francisco, created induced pluripotent stem cells using skin fibroblasts from a person with β-thalassaemia. They then used the CRISPR–Cas9 gene-editing technique to correct the unwanted mutation precisely, without affecting other genes. After differentiation in culture into precursors of red blood cells, the modified cells showed higher expression of HBB than unmodified cells.

Transplantation of such corrected cells back into the original patient could one day provide a cure for β-thalassaemia, say the authors.

Genome Res. http://doi.org/t3v (2014)