Your personal results go against the grain of what geneticists are finding out about Ashkenazi maternal lines in general, this article says that the biggest maternal line contribution is Italy:
http://news.sciencemag.org/biology/2013/10/did-modern-jews-originate-italyThe result was very clear-cut, the authors say: As reported online today in Nature Communications, more than 80% of Ashkenazi mtDNAs had their origins thousands of years ago in Western Europe, during or before Biblical times—and in some cases even before farming came to that part of the continent some 7500 years ago. The closest matches were with mtDNAs from people who today live in and around Italy. The results imply that the Jews can trace their heritage to women who had lived in Europe at that time. Very few Ashkenazi mtDNAs could be traced to the Middle East.
This is the way I imagine it played out: when the Roman Empire was still Pagan, wealthy Jewish merchants migrated to Italy and Roman elites were happy for their daughters to marry these rich foreign men because this was before Christianity had taken over and educated Pagan Romans perhaps respected and were curious about traditional Jewish Monotheism. The pairing of elite wealthy high achieving Jewish men with elite wealthy Roman women from high achieving families is what may have given Ashkenazi Jews such high IQs (they have higher measured IQs than any other group).
I also had my DNA tested at 23andMe. It turns out that my Y chromosome paternal line is Balkan, most likely Albanian / North West Greece. But my overall genetic profile is 95% "British and Irish".
What was your overall genetic profile? Did you get something like "90% Ashkenazi"? Or was it more mixed up?
By the way 23andme was also able to find some 2nd cousins of mine in Canada based on DNA matches alone, the technology is amazing!