Kevin has stated that the Pearl appears to be a lethal combination, he's not had any survive. I've not seen any adult Pearls the two times I've spent a week there, with full access to their collection, so I don't believe he's keeping that secret.
I am not sure I've seen a picture of a lesser/woma (no hidden gene) combo.
Thank you
I tought the exact same thing, no pearl survived yet. But I also heard that with other combination, they could survive, but I have never seen any of those, other than the baby lesser pearl from 2006 I think.