[muddyrivers]

As a molecular and cellular biologist in my previous life, I would say it is coincidence, although it is exceedingly rare, as you said. I don't see the possibility to acquire it, based on my understanding and training.

I want to provide some background, which is not typical, but pretty representative. In my 5~6 years as a biologists, I got my hands dirty extensively on 8~10 genes. It means I manipulated the genes in different ways via gene tools to try to figure out their properties. I knew every regions of these genes, even many single nucleotides, and what would happen if mutations occur at these nucleotides/regions. Other than that, I knew 50~60 genes very well. To this day, I can still remember most things about the genes. It is very sad that the random mutation happened to the lovely girl. If we only talk about statistics, the probability of the coincidence may be higher than we first thought.