Mayo’s first bone marrow transplant recipient, donor join celebration of 10,000th transplant

By In the Loop • October 26, 2022

Nancy McLain and Bonnie Engesmoe were 10 years old when they became the first bone marrow donor and recipients at Mayo Clinic. Bonnie donated her bone marrow to her identical twin, which cured Nancy of aplastic anemia and allowed her to live a long and happy life. Nearly 60 years later, Nancy and Bonnie returned to Mayo Clinic to help celebrate the success of the life-saving treatment they helped pioneer.

The first sign something was wrong with little Nancy McLain came on a trip to Disneyland. The seven-year-old "showed her mom a pillow stained with blood coming from her gums," she tells BMT Infonet.org.

When the family returned to their hometown of Canby, Minnesota, they took Nancy to a dentist, then a doctor. Eventually, the family was referred to Mayo Clinic, where Nancy was diagnosed with aplastic anemia.

At the time — 1960 — there were few treatments for the disorder. For the next three years, Nancy's life became a series of doctor's appointments and blood transfusions. ("I had 98," Nancy says. "My mom kept count.") She also had her spleen removed and was given last rites twice. She took medications that stunted her growth and altered her appearance.

The alteration was dramatic enough that her physician at Mayo Clinic, Robert Kyle, M.D., didn't realize that the little girl who accompanied Nancy to one of her appointments was her identical twin sister, Bonnie.

The discovery of an identical twin led to a potential treatment for Nancy: a bone marrow transplant. The procedure was experimental at the time and only being done with identical twins. If Nancy and Bonnie had the procedure, they would be Dr. Kyle's — and Mayo Clinic's — first bone marrow transplant patients.

"My mom could not make the decision because at the time there was a possibility of losing both of us," Bonnie tells KARE-11. "So she made me make the decision, which was very easy."

That "easy" decision was life-changing. Six weeks after the transplant, Nancy "was a twin sister again, with an ordinary life, running and biking faster than the boys."

Today, the sisters describe themselves as "happy grandmas." Their smiles were on display recently when they returned to Rochester to help celebrate a remarkable milestone: the 10,000 blood and bone marrow transplant performed at Mayo Clinic in Rochester. They reconnected with Dr. Kyle (still working at age 94) and joined him and other Mayo staff at a recognition event.

"Thank you for leading us down this road," William Hogan, M.B,. B.Ch., director of the Mayo Clinic Bone Marrow Transplant Program, said addressing Nancy and Bonnie. "It's really kind of awe-inspiring to think that there's 10,000 more patients that have followed in your footsteps."

Editor's note: Nancy hopes that sharing her story will inspire people to sign up to become bone marrow donors. According to Be the Match, bone marrow transplants can treat leukemia, lymphoma and more than 75 other life-threatening diseases. Learn how you can join the donor registry here.

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