How Much DNA Does The Child Of An Identical Twin Share With Their Parent’s Twin?

A child of an identical twin will share the same amount of DNA with the identical twin sibling of their parent as they do with their parent. This is because identical twins have the same genetic makeup, so the child’s DNA will be as genetically similar to their parent’s identical twin as it is to their own parent. While it may seem unusual, genetically speaking, the child’s parent’s identical twin is indeed as closely related as a biological parent in terms of shared DNA.