Thanks to a rare medical condition, a Washington state woman found out that pregnancy was not enough to prove motherhood;

DNA testing indicated that she was, in fact, not the mother of her own children – so who was? During the course of a desperate battle to retain custody of her three children, it was discovered that her twin was the real biological parent. The twist? She, 26-year-old Lydia Fairchild, was her own twin.

By the time Fairchild was 23 years old, she had given birth to two children and was pregnant with a third. Her relationship with the father had been rocky. They separated – not for the first time – and she found herself, at 26, a struggling, single mother; out of work and unable to support her kids. When she applied for government assistance, however, her world was shattered by an incredible revelation – one that led to criminal accusations and the impending prospect of losing her children to the state.

In order to qualify for financial assistance in supporting her young family, Fairchild was required to undergo DNA testing to prove that she was the mother of children for whom she was claiming. Jamie Townsend, the father of all three children, was also required to submit to testing. Having twice been through pregnancy and childbirth and now in the middle of a third pregnancy, this test, Fairchild assumed, was merely a formality. It turned out not to be, however; In December, 2002, Fairchild was contacted by the Washington state prosecutor’s office and told to come in to discuss the test results. To her horror, the young mother was informed that she would be the subject of an investigation into possible welfare fraud as the DNA tests had revealed no genetic link between her and the children she claimed were hers.

Townsend’s biological link to the children had been confirmed, but the test came up with no evidence that Fairchild shared any DNA with the three children. She found herself being interrogated by Social Services; who was she? Who was the real mother of the children? Jamie Townsend was also questioned and accused of fathering the children with another woman. “I knew that I carried them, and I knew that I delivered them. There was no doubt in my mind,” Fairchild later recounted. Fairchild’s obstetrician, Dr Leonard Dreisbach, was equally stunned by the accusation against the mother. “I’ve been doing this long enough to recognize when someone is giving birth right in front of you.” he said.

[…] In another part of the country, another woman was facing a similarly bizarre situation; 52-year-old Karen Keegan, from Boston, Massachusetts, had discovered that DNA testing – carried out to find a genetic match in the search for a potential kidney donor – indicated no genetic link between her and two of her own three sons. After confirming a match between Keegan and her youngest son, her doctors sought further advice and were informed that Keegan might have a very rare genetic condition know as chimerism. Derived from the name of a strange hybrid creature, the Chimera of Greek legend, this condition had been documented just 30 times throughout the world. Those rare individuals, dubbed “Chimeras”, had started out as twins; in the early stage of pregnancy, one of the twins had merged with – been absorbed by, one could almost say – the other twin.

The cells of the consumed twin, however, did not disappear and remained alive in one concentrated area of their sibling’s body. In essence, a human chimera is one person made up of two separate sets f genetic material; they are, in fact, their own twins.

[…] Determined to solve this medical mystery, the doctors tracked down material from the removed nodule to a medical lab in Boston. DNA extracted from the nodule matched that of her children.

Chimerism, however, was completely unknown to anyone dealing with Lydia Fairchild. Now in an advanced state of pregnancy, Fairchild found herself in court and about to lose custody of her children. The presiding judge ordered that blood samples be taken from her third child the moment Fairchild gave birth. Despite a court-appointed witness to the birth, tests on the blood samples, once again, showed no genetic link between the baby and its mother.

[….] That article had been written by Karen Keegan’s doctors and chronicled the incredible discovery they had made. Further exploration of the mystery of Fairchild’s DNA was ordered and a genetic link between her mother and her own children was confirmed. When Fairchild later had a cervical smear, DNA from it was tested and found to match that of her children. Fairchild’s lost twin, it appeared, had lived on as cells only found in her ovaries; she was her own twin – and the twin was the biological mother of her children.

Some sixteen months later, after enduring the harrowing prospect of even pregnancy being no proof of motherhood, Lydia Fairchild found the case against her dismissed. Her attorney, Alan Tindell, reflected on the dire consequences of oversight in the testing of DNA. “People go to death row because of DNA tests,” he said, “people are released from death row because of DNA tests.” As for Karen Keegan and Lydia Fairchild – two women separated by thousands of miles but linked by a rare genetic condition – their separate, but bizarre tales, may well have inspired the medical community – and the justice system – to think again about the potential shortcomings of DNA testing.