I hang out with the local DIY Bio group a bit (even though I know bugger all about this subject, really, and do not consider myself a "biohcker"), and somehow the subject of "targeted assassinations" came up. After part of that conversation, I walked away with the understanding that my interlocutor (who was an actual expert in some aspect of this overall field) was saying that - in principle - you could engineer a mosquito to both A. carry a deadly disease (Ebola, Zika, Malaria, ??) AND B. only be likely to bite somebody with a specific genetic profile.

As I recall, the individual I was talking to said that the didn't think it was possible to carry out that exact scenario today, but that it was close enough to reality to not be science-fiction, and would definitely be possible eventually.