http://www.politifact.com/punditfac.../fact-checking-reza-aslans-retort-bill-maher/
Aslan goes on some stretches at times, but his central point of confusing causal with correlative variables is important.
It's not a "Central African problem," not when the majority of those countries he points out are muslim countries, including Egypt (which isn't central africa, it's part of the arab world). And where female genital mutilation is practiced outside of Africa, it's almost exclusively practiced by islamic societies, where islamic teaching condones or mandates it.
here, he can explain it:
https://youtu.be/E9RmAo6XVAA?t=8m37s
http://www.huffingtonpost.com/david-pakman2/can-reza-aslan-be-trusted_b_8958290.html