I am fairly certain that Sabourjian is in fact an Armenian name. And as far as I know there are no Armenian Jews. So, if Ahmadinedjad is indeed a Sabourjian and if he is indeed trying to distance himself with his past, it would be a Christian past, not a Jewish one.
Egypt says verdict in Al-Jazeera case expected Saturday (AP)
from the article: Is Ahmadinejad trying to hide his Jewish roots by bashing Israel?