A pensioner has used DNA tests to trace her sisters after a lifetime of searching for her biological family.

Seventy-one-year-old Katherine Fisher, from Las Vegas, in the United States, was adopted by a couple who answered an advert in a newspaper. This unconventional form of adoption combined with some errors on her birth certificate meant she struggled to find her birth family.

Nine years ago, Katherine’s granddaughter Amiee Sands offered to help her locate her relatives.

Katherine told KLAS: “She said ‘I will find them’”

Amiee searched through census records, military records, yearbooks and telephone directories but didn’t manage to find any of her grandmother’s relations. However, she then turned to DNA testing to try and find a biological relative.

DNA testing revealed family members

Through testing, Amiee eventually managed to track down a first cousin who then put them in touch with Katherine’s biological sister Sonta Henderson.

Sonta had known her mother had given a sister up for adoption and had even kept the newspaper clipping in which Katherine had been advertised.

She said: “We didn’t know if she was alive, if she was not or where.”

Katherine has now met Sonta and another sister called Betty in Las Vegas.

She said: “I’m so happy, it’s so surreal. What a great Christmas present.”

Betty told KLAS: “I never thought this could happen in a million years. It’s just a dream come true.”

DNA testing is often associated with paternity tests, which can identify whether a man is the biological father of a child. However, it is also possible to identify whether someone is another form of biological family member.

AlphaBiolabs offers a range of family relationship tests, including sibling DNA tests. It is also possible to identify whether someone is a grandparent, aunt of uncle through genetic testing.

Y chromosome testing is able to determine whether two men are biologically related to each other through their paternal line. This test works because the Y chromosome is passed onto men from their father unchanged and only mutates once every 10,000 years.

This means if two men are related through their paternal line, they will share the same Y chromosome as each other.