BioCentury
ARTICLE | Preclinical News

Researchers use base editing to correct beta-thalassemia mutation

September 29, 2017 8:41 PM UTC

In a paper published in Protein & Cell, researchers at Sun Yat-sen University and colleagues used a gene editing technique called base editing to correct a single point mutation in human cells and embryos that causes beta-thalassemia. The researchers, who were the first to use CRISPR to edit the genomes of non-viable human embryos as published in 2015, suggest the technique could repair disease-causing point mutations without the inefficiency and off-target effects of homologous recombination (see BioCentury Extra, April 23, 2015).

The base editor is a protein-RNA complex adapted from the CRISPR-Cas9 (CRISPR-associated protein 9) system that can convert single base pairs without cutting DNA. An effector protein comprising an inactive form of Cas9 with cytidine deaminase and uracil DNA glycosylase inhibitor directly converts cytidine (C) to thymine (T) and guanine (G) to adenine (A). Guide RNA (gRNA) directs the Cas9 conjugate to its target site. The approach was pioneered by David Liu at Harvard University, who first described the system in a 2016 paper in Nature and subsequently designed more efficient base editing versions (see BioCentury Innovations, May 5, 2016 and June 29, 2017)...