When two pairs of identical twins are combined, the children they give birth to are cousins or cousins. However, genetically speaking, they are actually brothers.
Checking each child’s DNA, even scientists can’t determine which couple the child belongs to, because their parents are identical twin brothers and sisters, and the children’s genes come from the same gene pool.
Therefore, their genes are highly similar, just like brothers. But even so, this does not mean that these children are all exactly the same.