Some identical twins don’t have identical DNA
Mutations arising early in development may account for genetic differences
![twin girls](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2021/01/010721_TI_twins_feat.jpg?fit=1030%2C580&ssl=1)
Identical twins were thought to be genetically the same, but a new study finds that’s not always the case.
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