Mutants are less of a species, and more the victims of the errant energies released. Whether these deformities were caused by technological or magical means matters not. Mutants are not shunned and there aren't many of them, thus they never formed their own society.
Constructs that have been made with organic components can mutate as well.
Must obviously have a deformity
This will depend on the original species the character mutated from. If born a mutant, you will need to talk to plot and we will help you figure out what the feats and skill is that you will be able to start out with endemicly.