The coverage issue is why you can't go out and get any one of a hundred edits [2] and expect things to happen as a result. As soon as that is robustly solved, well, gene therapies will be out there in the medical tourism market, starting with telomerase, myostatin, and follistatin, I'd imagine. Most likely the second of those up front since its already fairly robustly proven in humans via antibody therapies. [3]
I would be extraordinarily surprised to find that there were no humans already tinkering with their myostatin balance via genes or antibodies, given the number of people with access to the technology, and the ease with which such a therapy could be assembled.
[1]: http://www.nature.com/cr/journal/v26/n5/full/cr201628a.html
[2]: https://www.fightaging.org/archives/2016/06/a-short-list-of-...
[3]: http://news.iupui.edu/releases/2015/12/myostatin-warden-musc...
They are also a heap of excessive effort when a sniper rifle or drone missile works fine.
I also fail to see how it could help to create something like FOXDIE (I have only read a short wiki article about it)? I mean you can create viruses with a certain sequence already now, so is no clear connection between creating a targeted virus and genome editing? Sure, you can edit the genome but injecting a single malicious gene is much easier (which seems to be the case for the fictional FOXDIE)