Extraordinary
People

Lydia Kay Fairchild

The Twin Inside Me - Chimera

The Twin DNA

Lydia Fairchild
Lydia Fairchild

Lydia Fairchild was twenty one when she had her first baby. Despite being separated from the baby's father, Jamie Townsend, she and Jamie had a second baby a year later. Another year on and and she became pregnant for the third time after which she and Jamie split up again. With no steady work and unable to support herself and the children she applied for state benefit.

Her world was about to be turned upside down.

The State Prosecutor's Office required DNA tests from Jamie to prove that he was the father of the children and, as a matter of course, Lydia was also tested.

In December 2002 she received a phone call from the prosecutor's office asking her to come in for the results. This was unusual and it soon became apparent why. The results confirmed that Jamie was the father but they also revealed that Lydia was not the mother. A normal DNA test proving a mother-child link would show a 50% match between their DNA patterns. Yet Lydia's DNA showed no match at all.

The state prosecutor started an investigation. Lydia and her family feared that a case of welfare fraud was being mounted against them. Suspicion spilled over to Lydia's estranged partner, Jamie Townsend, he was interviewed and accused of fathering the children with another woman. The family knew they were under suspicion. Even the medical evidence they had of the children's births didn't seem to count.

Dr Leonard Dreisbach
Dr Dreisbach

Dr Leonard Dreisbach, Lydia's obstetrician said: "I've been doing this long enough to recognise when someone is giving birth right in front of you. The babies are footprinted at the time, in the delivery room, and the cards are filed as proof of the birth. This may be an older technology but it has worked well in the justice system for many years."

Lydia, pregnant with her third baby, faced continued questioning by the state prosecutor and was, at one point, threatened with a lie-detector test, which she would have welcomed. All of this culminated in a summons being issued. Lydia was being taken to court.

Meanwhile, 2,500 miles away in Boston, Massachusetts, Karen Keegan a 52 year old teacher was confronted with the same startling information. According to DNA testing her children were not hers. Karen had been in urgent need of a kidney transplant and she and her family were tested to find a matching donor. Just as in Lydia's case, there was no genetic match between Karen and her eldest two boys.

During her treatment, Karen met transfusion specialist Dr Lynne Uhl who became intrigued by her story. Dr Uhl arranged to have Karen and her boys tested again. Her youngest son was tested for the first time and he was a match! The doctors sought advice from senior colleagues and it was one of these who suggested Karen might be a chimera. A chimera is someone who has two completely different genetic identities, two sets of DNA. It is believed that a chimera is formed when two fertilised eggs fuse together, early in their development.

Karen Keegan
Karen Keegan

To prove Karen was a chimera, doctors had to find the second DNA somewhere in her body. Her doctors got funding for a dedicated research project. They enlisted the help of immunologists at the American Red Cross and Harvard Medical School.

Tests on her hair and skin samples proved fruitless, so doctors decided they needed to take samples from her internal organs. Dr Uhl was fortunate: "She's had some prior surgery and we were able to retrieve specimens from the pathology department, in particular the thyroid tissue and tissue obtained from her bladder."

The tests were painstaking and it would be months before Karen's diagnosis could progress. Karen's doctors were determined to understand the mystery of her DNA.

It was very different for Lydia Fairchild, No-one dealing with her case had even heard of chimerism and she was about to go to court to establish the parentage of her children. She could not even get a lawyer to take her case as they all considered the DNA evidence irrefutable.

Jamie Townsend
Jamie Townsend

In court, the prosecution wanted guardians to be appointed for each child, to monitor their welfare while the investigation continued. Based on the existing evidence, the judge agreed that Lydia was not their biological mother. For Lydia and Jamie, their worst fears had lust been confirmed.

Lydia was now heavily pregnant with her third child. The judge realised that this latest pregnancy could provide vital clues to help unravel the mystery. He ordered that someone be present at the birth to act as witness and to take blood samples immediately after the birth.

These latest DNA test results were arresting. They showed no match between Lydia and the baby. It was what the family wanted to hear and Lydia finally got a lawyer to help her.

Alan Tindell, Lydia's attorney commented: "The questions that have gone through the prosecutor's minds include whether or not she was involved in being a surrogate mother. If the egg and sperm had been implanted then she wouldn't have any relationship to the child. Maybe she'd abducted the children from somewhere or was involved in some other criminal activity"

It seemed that only science could provide the answers. By an extraordinary chance it did, when the state prosecutor stumbled across a new lead for the case. The deputy prosecutor had found an article in The New England Journal of Medicine about chimerism.

For the first time the question was raised "Could Lydia be a chimera?" Lydia and her attorney went back to court where the judge agreed to postpone the hearing while they tried to find out more.

By amazing chance, the stories of Lydia and Karen now met. The paper in the medical journal had been written by Karen Keegan's doctors who had made a major breakthrough.

Karen explains: "Both of my brothers as well as my mother donated blood samples which were sent to Boston." These family test were to prove key. Comparing the DNA from family members led to a bizarre result. It looked as if Karen's sons were descendants of her husband and her brother!

Having established that the boys were members of this family and carried Karen's father's DNA, it still remained to find the DNA in Karen. Finally the doctors struck gold. Testing the thyroid tissue revealed the missing DNA. Further testing showed that the, in fact, both sets o DNA were present in all of her tissues but one set was more dominant than the other.

After being approached by her lawyer, doctors at the Beth Israel Hospital agreed to investigate Lydia's DNA.

What the scientists quickly established was a DNA link between the children and Lydia's mother. Just as with Karen, the DNA was in the larger family. This finding along with the medical records of Lydia's first two deliveries was submitted to court as proof that Lydia really was the mother of the children.

The court concluded that Lydia was the real mother and Jamie Townsend the father of the children, sixteen months after the first DNA result had come in. Everyone involved in Lydia's case recognised it's dramatic implications. In the first court hearing the judge openly wondered how far DNA tests could be relied upon.

Lydia's Boys
Lydia and Jamie's Children

Alan Tindell elaborated: "The courts rely on these tests to a great degree. People go to death row because of DNA tests, people are released from death row because of DNA tests."

DNA testing is hugely influential in criminal cases. Armies of forensic scientists are employed to look for matches between the DNA at a crime scene and a suspect. What if the criminal is a chimera?

It was not until Lydia had a cervical smear that the elusive DNA was found. This led to speculation that Lydia may be chimeric only in her ovaries.

Both Lydia and Karen could have gone through life never knowing that they were chimeras if they had not undergone DNA testing. How many more chimeras exist and simply go undetected?