It is folk knowledge that in-breeding causes birth defects due to similarity of genetics between parents. Consequently, is there a similar correlation between genetic distance of parents and probability of birth defects?
The best reference I can find of this is this handout by the Australian Centre for Genetics Education which says:
If parents are unrelated, their chance of having a child with a birth defect or disability is between 2% and 3%.
If parents are first cousins, the chance is a little higher at 5% to 6%. This is due to the increased chance that they will both carry the same autosomal recessive mutation, passed down through the family.
However this doesn't talk about genetic distance in particular.
This question is really just a more specific version focused on a single metric (genetic distance) and outcome (birth defects) of two previously answered questions: