The U.S. Constitutionâs 10th Amendment is arguably the most important of all the amendments in the brilliant document that helped shape the United States.
Not even identical twins have the same DNA--although theirs would be far closer than anyone else's. DNA changes over time. Odds of two siblings having the same DNA who did not split from the same zygote are vanishingly small.
If two brothers happen to share markers at all of the sites tested, then the wrong man can be identified as the dad. But again, unless they are identical twins, the brothers will not match up at every DNA position. If a company looks at enough DNA, they will be able to tell who the dad is. And a company will do this if you tell them that either brother might be the dad.