Doppelgänger Is Out There and You Probably Share DNA with Them

As I understand it, DNA is not shared between dopplegangers ancestrally (as in siblings or twins) but coincidentally through combination or epigenetics.

I wonder if there is opportunity for something similar to twin studies whereby the same/similar genetic information is used to understand affects on other characteristics.

Earlier story from 2020: https://www.bbc.com/future/article/20160712-you-are-surprisi...

2015: https://globalnews.ca/news/2300048/your-doppelganger-exists-...