>>3011808No. The genetic risk for having a child with your sister when you're both 20 is lower than having a child with a woman 35+. Unless you have an abnormally high risk for heart disease or something and fail to get genetic testing you'll be fine. The data for this is skewed because most of it comes from jews and Indians- two groups who have long histories of inbreeding. The Indians especially do not do genetic testing because they know how the practice is frowned upon in the west.
Sort of same deal for anyone else actually, since it's taboo/illegal couples that actually engage in incest are unlikely to seek testing so it's hard to determine what the empirical genetic risk is as opposed to, say, a family that has a history of heart disease on one side and diabetes on the other who wind up with problems because they were already high risk to begin with.
