The abundance of harmful homozygous rare variants in children of consanguineous parents

Abstract Here we show that the individuals born of the union between double first cousins (paternal and maternal) had 20 times more deleterious homozygous rare Single Nucleotide Variants (SNVs) than those who had unrelated parents. Furthermore, the children of first cousins had ten times, and the children of second cousins had two times more of these SNVs compared to those present in the offspring of unrelated parents. These results suggest that the offspring of closely related parents could have a 2 to 20 times higher risk for rare recessive diseases than the children of unrelated parents.