Consanguineous

Consanguineous is the mating between two individuals who are related as second cousins or closer. Mating between relatives is important for recessive alleles to become homozygous. When a recessive is rare, it is more likely to become homozygous through inheritance from a common ancestor than from parents who are completely unrelated. Therefore, consanguineous marriages increase risk for congenital malformations and autosomal recessive diseases.