Andrew:
My daugther (10 years old) is called Izanna. She lives in Amsterdam, Holland, and she is not of African origin, neither her name is. My wife and I wanted her name to be a combination of
Anna and some other letters/sounds; we had also some names with Z in mind; then it became Izanna.
In the 19th century in Linn County (Ohio) there lived a Izanna Chamberlain who wrote a book about the prairie. That's information I found on the web.
I can tell you also that Izana is the name of a river in Spain. (With one N - in Spanish there are no words with double N)
What were the results of your investigation to the name 'Izanna' so far?
Beste wishes,
Gijs Mulder