: For first cousins, the risk increases to roughly 6%. While this is a doubling of the baseline, some researchers argue it is not as high as public stigma suggests.
: Outside the Western world, cousin marriage remains a preferred practice in many societies in the Middle East, South Asia, and North Africa. Genetic Considerations: Myth vs. Reality Kissin' Cousins
: Children of unrelated parents have a 3% risk of congenital defects. : For first cousins, the risk increases to roughly 6%