Are you identical or fraternal? If you share the same level of intelligence-then you will probably get accepted, too

just kidding.
I think it could be a plus-unless your grades are really bad. If your grades are bad, just explain that you are really close and that separating the two of you could be a really bad thing for both of you. Just look at what happened to the Olsen twins.

Just kidding again.
My brother will be a year behind me in medical school (he's applying next year) I think the fact that he knows about the school I'll be attending because of our relationship conveys to the admissions committee that he knows what hes getting into and would feel comfortable there.
Its definitely not a for-sure way of getting in. Legacy is waaay over-rated. I applied to the allopathic school my mother went to, and even though my grades were at their average of matriculants, they didn't accept me. Surprise!
i hope you get in with your bro, though. Twin doctors... wow!
😍