We recently introduced some new members to our Dark Heresy group among friends who had been interested in playing for a while. And one of them expressed interest in creating a mutant dreg PC. Ruleswise it was possible (all we had to do was decide that he rolled 01 on the Divination table during character creation), he wanted the "Brute"-mutation so I let him have it. He had a pretty good vision of the character so I didnt see any harm in letting him have his way, although i made it abundantly clear that mutants and abhumans suffer from severe discrimination (if not persecution) on most Imperial worlds.
In the end he happily ended up with an ex-penal legionaire mutant guardsman (explosive collar still attached for obvious reasons). It seems he could also work in moderately social situations due to him having the brute-mutation which although causes several malformed musclegrowths on the body, it could be covered up with appropriate clothing.
Im curious if anyone else have had players expressing interests in creating mutant and/or abhuman PC's and how that have worked out? For normal games the rules certainly dont seem very designed with that in mind, but I wonder if it could be interesting to have some "official" rules for creating, lets say Ratling or Ogryn PC's? (the guy who wanted to create an abhuman earlier had in mind to create an Ogryn character, but I found it difficult rules wise so he had to settle with a brutish freak mutant instead)