Numerous complications could go unnoticed in this study
On 26th July, the journal MIT Technology Review announced that the CRISPR technique (see HERE) had been applied in human embryos for the first time in the United States, in a study led by embryologist Shoukhrat Mitalipov of Oregon Health and Science University.
Gene editing has previously been performed on human embryos on at least three occasions in China. Accordingly, two articles from 2015 (see HERE) and 2016, respectively, reported the application of CRISPR on non-viable human embryos (see HERE) . Subsequently, in 2017, another paper reported the application of CRISPR on human embryos, this time viable (See HERE ). In all cases, the results revealed that there are still serious safety and efficacy obstacles before the method can even be considered for use in medical applications. Consequently, the editing was completely successful in only a very small number of embryos, and moreover, there were undesirable effects like mosaicism (when only some of the embryonic cells incorporate the desired change) and off-target mutations.
The findings of the new study were published on 2nd August in Nature. Most relevant, though, is not the fact that viable human embryos have been edited for the first time in the US, but that the problems of mosaicism and off-target mutations found in previous studies appear to have been largely overcome.
The experiment consisted of correcting a mutation in the MYBPC3 gene, which causes a heart disease. The mutation was found in the DNA of the sperm used to fertilize the eggs.