I've heard many different opinion's about it. In my opinion, I would not let them breed. I'd look for a different bloodline.

That said, lot's of morphs are bred mother to son. I've also heard that most of t.s. tetrataenia that can be bought in Belgium/The Netherlands are from 1 couple ( I don't know if it's correct, I've heard this). So it can produce a healthy litter.