The berserk gene raises your attack by six stages, just like belly drum, and makes you permanently confused. Even if you baton pass the +6 stat boost, the confusion status gets passed on too. This could be circumvented by having the Pokemon you baton pass to hold an item that cures confusion. In that way, Berserk Gene would be pretty gnarly in a baton pass set like that. It could even be game breaking, because it is the Belly Drum without the HP-halving. But there is still a good chance your Pokemon will hit itself in confusion and get defeated before it can use Baton Pass, so it is really ballsy. Super-risky, but it would make one heckuva sweep.
I was just thinking about this stuff involving the Berserk Gene the other day. Very cool.
ADDITIONAL: Disregard the +6 boost, it's really just a +2 boost!