A decade ago, Denise Shields of Laguna Niguel and Nancy Hinkeldey of Orlando, Fla., went to China with a group of other Americans intent on adopting.
Shields had lost her husband and was aching to raise a child. Hinkeldey, a single mother with one adopted child, wanted another. Their mutual yearning was satisfied at an orphanage in the southern city of Nanning. Each flew home with a baby girl.
Over the years, Shields sent holiday photos of her daughter to the other families who had made the trip. As the photos piled up, Hinkeldey began seeing subtle similarities between Emily Shields and her daughter Anna. She saw it in their jaws and cheek lines, in their eyebrows and foreheads, in their hairlines.
Last July, as the girls romped on the beach at their travel group's 10-year reunion on Amelia Island, Fla., the mothers compared notes.
Both girls had been late losing their baby teeth. Both were academically gifted, musical and artistic.
Then Shields noticed a peculiar indentation on the back of Anna's right thigh. She grabbed Hinkeldey's arm and blurted out: "Anna has the same mark Emily does!"
The two women discussed with their daughters the idea of DNA testing. Anna and Emily agreed. The news came in August: The girls shared at least one birth parent, making them biological half-sisters. The lab could not rule out the possibility that they had both parents in common.
DNA testing has been used for years to convict felons and clear those who've been wrongly accused. Now, families are turning to the technology to establish biological links between adopted children living in different households, often hundreds or thousands of miles apart.
In doing so, they are penetrating the mystery that often surrounds adoption and recovering bits of the lost history of children from China, Russia and other foreign lands, many of whom were delivered to their adoptive families as foundlings, with little or no information about their origins.
One e-mail group has drawn more than 60 adoptive families who serve as a far-flung support group. Many of those parents say they have spotted children on family or orphanage websites who bear strong resemblances to their own. Some have confirmed blood relationships through DNA testing.
Recently, two families in Arizona and Alabama learned that their adopted children from China -- both born with cleft palates -- were at least biological half-siblings.
In August, a company in Princeton, N.J., announced that it had agreed to conduct genetic testing for a nonprofit registry that is believed to be the first to focus on using genetic profiles to reunite siblings after adoption. Other such registries are scrambling to enter the market.
The practice is stirring up a commotion in adoption circles. Some adoption specialists and bioethicists say they fear that unscrupulous labs will exploit parents eager to fill in the missing pieces of their children's lives.
Another worry is that adopted children could find the sudden discovery of a sibling profoundly unsettling. Some experts say parents should wait until their children reach adulthood and let them decide whether and how to seek out long-lost family members.
Bioethicists and educators also caution that DNA tests conducted without genetic material from the parents (typically the case with children from China) can often prove inconclusive.
"Before we all go flying off getting our DNA tested, we need to have some thought given to what is going to happen when we get these results and how we'll interpret them," said Jane Gitschier, a professor of medicine and pediatrics at UC San Francisco.
The push for DNA tests would seem to go against a central tenet of adoption: that families created through that process are just as authentic as those based on blood relationships.
Hinkeldey and Shields believed they owed it to their daughters to find out whether the similarities between them were accidental or hereditary.
"We felt it would be doing them a disservice not to," Hinkeldey said.
Both mothers knew it was a long shot and said as much to their daughters. "I talked with Anna about the possibility of disappointment," said Hinkeldey, a psychologist. "I told her this was a very unlikely thing."
Hinkeldey said she was also concerned about how her other adopted daughters -- Eva, 12, and Lily, 5 -- would react if their sister learned she had a blood relative. As it turned out, they were overjoyed by the discovery and have welcomed Emily Shields into their family.
The decision to seek DNA testing involved a leap of faith akin to that the mothers took when they adopted in the first place.
"I absolutely wanted a child," Hinkeldey, 48, said of her life before adoption. "It was something I needed to do."
