For the first time in the US, a number of one-cell human embryos have had their DNA modified using the gene-editing tool CRISPR. Scientists in China have been doing the same thing for the last two years in a number of experiments - including one that make them HIV resistant - but not with out issues.

There have been problems with CRISPR causing editing errors in the DNA - but the US research (which is yet to be published) apparently avoids this problem.

Here's what Australian experts have to say about the news.