Several years ago my friend Fred set up a family tree on Ancestry.com. He’s always been fascinated with his family history — especially with his mother’s side of the family, which perished in Europe during World War II.

He later became engrossed with DNA testing as a vehicle to understand his roots. He subsequently was tested with Ancestry.com and another popular site, Family Tree DNA.

Both companies provide data on your ethnic origins and automatically match you with people who share your DNA, thus helping to connect with relatives. As a result, Fred often received email from people who were listed by the websites as distant cousins. The problem was, they were so distant, he couldn’t figure out the genealogical connection.

That all changed on his birthday in April when he received a message from a stranger named Cindy via Ancestry.com. What she brought to his attention was that they both shared about 800 centimorgans of DNA, enough to be first cousins.

Fred was incredulous, but he couldn’t argue with the results. How could this woman whom he’d never heard of be so closely related?

Fred decided that this was a mystery he had to resolve.

He began a series of telephone conversations with Cindy, who lived in Washington state. She told him upfront she knew next to nothing about her birth mother and had never met a blood relative. She did know she had been given up for adoption in 1948 in San Francisco. This happened to be Fred’s hometown.

Fred learned that, at age 69, Cindy was not in good health. With the clock ticking, she was on a mission to discover the identity of her birth family.

As the dialogue continued, a tantalizing clue came to the surface. Cindy recalled being shown an adoption paper signed by her birth mother.

“Do you recall your birth mother’s name?” Fred asked. She didn’t recall her birth mother’s first name, but she clearly remembered the last name, which was the same as Fred’s.

It was a crucial detail. Fred’s father had two unmarried sisters in 1948, Sarah and Beth. Both lived in San Francisco at the time. Aunt Sarah had died several years ago, but Aunt Beth, age 93, still lived in the city.

Could one of them be Cindy’s mom? It sure looked that way. Aunt Beth would surely know, but she suffered from dementia and wasn’t available.

What he needed was DNA samples from his cousins, the children of Beth and Sarah. Testing his cousins’ DNA would conclusively prove whether one of his aunts had given birth to Cindy.

He decided to start with a clean slate and have all the tests done with Family Tree DNA. FTDNA was affiliated with the National Geographic genome project, and that kind of credibility gave Fred confidence that the data would be solid.

The tricky part was to tactfully explain to his cousins why they needed to be tested.

Aunt Sarah had two surviving children, and the youngest, Ralph, quickly volunteered. Ralph had been close to his mom, and if she had given up a child for adoption, he was certain she would have wanted him to know.

Fred requested that Aunt Beth, or any one of her three children, also take the test, but all declined.

Six weeks later Ralph’s test results came in and confirmed Fred’s hunch.

FTDNA determined that Ralph and Cindy shared 2,591 centimorgans of autosomal DNA. This could only mean they shared the same mom and dad. They were full siblings.

Fred reckoned that his Aunt Sarah had to give up Cindy for adoption because it wasn’t certain that her future husband, Cindy’s dad, would marry her. The stigma of being an unwed mother was more than her family could handle.

The conclusion of the story was bittersweet.

Cindy was delighted to finally discover her parents’ identity.

Fred hoped the rest of the clan would welcome Cindy into the fold, but he couldn’t promise her that.

If you’re interested in delving into your family roots, Family Tree DNA’s tests start at $89. I’d encourage anyone curious to take the test, but be prepared to have your world rocked.

Mike Meyer is chief information officer for Honolulu Community College. Reach him at mmeyer@hawaii.edu.