A single mother in Wales is sharing her story after learning that just one person in the world may hold the key to saving her life.

Sian Chathyoka was diagnosed in September 2025 with an aggressive form of myelofibrosis, a rare blood cancer that affects the body’s ability to produce healthy blood cells. According to the charity Anthony Nolan, Chathyoka is currently the only patient in the Swansea and Cardiff area known to be diagnosed with this specific form of the disease.

Now 56, Chathyoka is awaiting a stem cell transplant and recently learned there is only a single matching donor available on the worldwide register.

“It’s absolutely petrifying,” she said. “But you’ve got to forget about that and be positive.”

Before her diagnosis, Chathyoka led an active outdoor life. She regularly swam in the sea year-round and helped manage her family’s seaside campsite. That all changed in August, when overwhelming fatigue left her confined to bed.

“I’ve had such a level of fatigue, I haven’t been able to do anything, and it’s been quite scary,” she said.

Myelofibrosis occurs when a blood-forming stem cell mutates into a cancerous cell, crowding out healthy cells and damaging bone marrow, according to the Cleveland Clinic. The condition’s cause is not fully understood, and symptoms can take years to appear. Fatigue, unintended weight loss, and an enlarged spleen are among the warning signs.

Chathyoka became alarmed when extreme exhaustion and unexplained weight loss prompted further medical tests. Scans later revealed an enlarged spleen, and she was referred to hematology specialists, who delivered the devastating diagnosis.

“I couldn’t stop crying,” she said. “My condition is very rare and I’ve been told my disease is aggressive as well.”

Since then, she has required weekly blood and platelet transfusions, along with treatment to reduce the size of her spleen. Despite the fear, she says discovering there is a possible donor has given her hope.

“I’m lucky. I’m grateful that there is the possibility of a cure through a stem cell transplant,” she said.

Stem cells can be collected from bone marrow, peripheral blood, or umbilical cord blood, according to the American Cancer Society. Donors must complete health screenings and blood tests before being approved.

Chathyoka has now partnered with Anthony Nolan on a campaign called SignUpForSian, urging people worldwide to join the stem cell donor register.

“What I’ve realized throughout this process is that nobody knows about stem cell transplants,” she said. “Just signing up to the register, you can literally save a life. That’s how powerful it is.”

As she waits for her transplant, Chathyoka hopes her story will inspire others to act — not just for her, but for countless patients still searching for a match.