Map:
http://consang.net/index.php/Global_prevalence
Background:
http://consang.net/index.php/Summary
"As a working definition, unions contracted between persons biologically related as second cousins (F ≥ 0.0156) are categorized as consanguineous. This arbitrary limit has been chosen because the genetic influence in marriages between couples related to a lesser degree would usually be expected to differ only slightly from that observed in the general population."