Frightening Levels of Incest Exposed by DNA Tests

At-home DNA testing kits such as 23&Me and Ancestry DNA are exposing the horrifying rates of incest in the US.

DNA tests run for around $100, and whilst those tests cannot say if someone is a product of incest, third-party genetic testing firms can. And it's leading to many discovering disturbing truths about their family, such as Victoria Hill.

Hill, who is 39-years-old, started talking about family trees with an ex-boyfriend at their high school reunion after she had taken a DNA test. Their family makeup was similar, so her ex-boyfriend decided to take the same test Hill took. Then Hill received a text confirming their fear: she was his sister.  Speaking to CNN about the discovery, Hill said: "Now I'm looking at pictures of people thinking, well, if he could be my sibling, anybody could be my sibling."

In another shocking incident, Steve Edsel found out through AncestryDNA that his parents were first-degree relatives, meaning either sibling or father-daughter. Meaning his conception was likely a result of sexual assault.

Incest in the US is far more common than once thought, with the rate at one in 7,000.  Babies born as a result of incest are at an increased risk of having birth defects and genetic disorders, such as blindness and hearing loss.  Genetic disorders occur when related individuals get pregnant because genetic variations decrease, and the recessive gene they have may combine to become dominant in their child.

This would surely raise concerns about about giving birth to a baby with life-threatening genetic anomalies.   One such person is 64-year-old Teresa Weiler. She found out in 1985 that her father was her mother’s brother.   She said: "It was only when I was walking the streets afterwards, in a daze, that it hit me: I could never be a mum.  There was no way I could risk having a damaged baby. I would have to give up the one thing I wanted most in the world."

If someone wants to test for possible incestuous history in their family, they have to upload their genetic material to a third-party service, as this is not something that Ancestry DNA or 23&Me can disclose.  Third party tests look for homozygosity, or ROH for short, due to children born of incest's DNA containing large chunks of identical genetic material.