Wikitree doesn't collect or store any DNA data other than what test or tests you have taken or sites like Gedmatch where you have uploaded your raw data. Your profile shows that you have added your DNA test information to your profile, so that test propagates back through your tree as you add or connect your relatives. That will help you identify other Wikitreers who may share DNA with you. Your brother will need to add his own test information; for privacy reasons you cannot add DNA information for any living person other than yourself.
