Being a dragon is not something you can be. Dragons do not exist, much less is there the capacity for a human being to be one.

Having different chromosomes is also not something you can do.

You might argue, that people with chromosomes different from yours exist. This is irrelevant tho, because neither can you change your chromosomes nor can you rule out someone genetically engineers a fantasy style dragon one day.

Also: https://en.m.wikipedia.org/wiki/Komodo_dragon

(PS: I should maybe note that I have the dragon person blocked for different reasons tho)