A one-step procedure can correct genetic mutations in body cells and reprogram them into stem cells.

Stem cells derived from patients' tissues could generate replacement tissue that is not rejected by the immune system. Current methods have stem-cell yields of only 0.5–0.9%, and require extra steps to correct any mutations. Sara Howden, now at the Murdoch Children's Research Institute in Parkville, Australia, and her team introduced into cells a mix of genes that induce stem-cell formation and encode the components of the CRISPR–Cas9 gene-editing system.

They targeted mutations in cells from two people — an adult with a degenerative retinal disease and an infant with severe combined immunodeficiency — and made stem cells without the defect. The method produced stem cells with 5–8% efficiency.

Stem Cell Rep. http://doi.org/87t (2015)