Genetics in Medicine — Progress and Pitfalls

Last week, the White House decreed that human germline gene editing in biomedical research is discontinued in the USA until ethical and safety concerns are resolved. This technology involves modification of the genome in germ cells, which can then be inherited and passed on to future generations. “The administration believes that altering the human germline for clinical purposes is a line that should not be crossed at this time”, said John P Holdren, Director of the White House Office of Science and Technology Policy.

In recent years, genome engineering technology has developed the ability to edit DNA more precisely than before. The new technology is based on an enzyme complex that binds and splices DNA at precise locations, and can target a dysfunctional gene by first deleting, then repairing or replacing the target sequence with another molecule. One such technique, CRISPR/Cas—short for clustered regularly interspaced short palindromic repeats—has received attention after a study from China used the technique for the first time to edit nonviable human embryos to disable the gene for β-thalassaemia. However, the study...