Is female circumcision a Sunnah, and if so, why is it only practiced in Egypt?

The scholars have concluded that female circumcision is supererogatory (recommended), and the imams have agreed upon its permissibility, though they differed on whether it is obligatory, supererogatory, or an honorable deed. It is stated in the fatwas of the Permanent Committee for Scholarly Research and Ifta: "Circumcision is among the traditions of the natural disposition (fitra), and it is for males and females, except that it is obligatory for males and a sunnah and an honorable deed for females." Ibn Baz said: "Female circumcision is a sunnah if a male doctor who excels in it or a female doctor who excels in it is found."