Surname DNA Project
There is a DNA project for the Birmingham/Bermingham/Burningham/Brimingham surname.
It is possible that there are many different families all bearing the Birmingham surname (i.e. the original de Birmingham family, their servants/followers/slaves, newer families and name changers). Then again there may be very few. As more Birminghams join the project, and get their DNA tested, the truth will be revealed.
The homepage of the Bermingham DNA Project is at:-
http://www.worldfamilies.net/surnames/birmingham/homehttp://www.worldfamilies.net/surnames/birmingham/home