The girl with three biological parents

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"A lot of people say I have facial features from my mum, my eyes look like my dad… I have some traits from them and my personality is the same too," says Alana.

"I also have DNA from a third lady. But I wouldn't consider her a third parent, I just have some of her mitochondria."

Mitochondria are often called the cell's factories. They are the bits that create the energy all of our cells need to work, and keep the body functioning. But they also contain a little bit of DNA.

Alana Saarinen is one of only 30 to 50 people in the world who have some mitochondria, and therefore a bit of DNA, from a third person. She was conceived through a pioneering infertility treatment in the USA which was later banned.

http://www.bbc.com/news/magazine-28986843