Wiskott-Aldrich Syndrome (WAS) — Third Bone Marrow Transplant After Two Prior Failures, Myeloid Malignancy, and Haploidentical Parent Donor Transplant in China: A Patient Story for International Families Facing Rare Paediatric Immunodeficiency, Failed Transplants, and No Remaining Local Options — Including Families in South America, Southeast Asia, and Other Regions Without Access to Specialist Transplant Programmes

A Rare Diagnosis at the Age of Weeks

Leo was born in Argentina in July 2017. Within weeks, he began presenting with recurring fever and diarrhoea. Initial investigations at a local hospital were inconclusive, and he was transferred to a specialist children's hospital in the capital, where his severely low blood counts prompted urgent investigation.

The diagnosis was Wiskott-Aldrich syndrome (WAS) — a rare X-linked primary immunodeficiency that affects both immune cell function and platelet production, leaving children vulnerable to severe infection, uncontrolled bleeding, and over time, an elevated risk of malignancy. The medical team was clear: the only curative approach was haematopoietic stem cell transplantation.

Leo spent much of his first months of life in intensive care. He received blood transfusions and required close monitoring. His family, running a small business in Argentina, reorganised their lives entirely around his medical needs.

First Transplant. Second Transplant. Both Failed.

At the age of two, Leo received his first bone marrow transplant. The graft failed to engraft. The cause, as determined later, was cytomegalovirus (CMV) infection during the engraftment window — a complication that can be mitigated with prophylactic antiviral protocols, but the treating hospital had no such standard protocol in place at the time.

A year later, the same team attempted a second transplant using remaining donor cells from the first procedure. This too failed to engraft.

In the wake of two failed transplants, Leo developed myelodysplastic syndrome (MDS), which progressed to a myeloid malignancy. When his family asked about a third transplant, the answer was unambiguous: the local team would not proceed. The cumulative risk, in their assessment, was too high.

From that point, Leo visited the hospital every week for platelet transfusions. There was no curative plan. There was only maintenance — and the slow, exhausting weight of watching a child live without a path forward.

October 2025: A New Crisis, and a Doctor Who Said "There Is Still Hope"

In October 2025, Leo's condition deteriorated sharply. His platelet count dropped to near zero. When venetoclax — a targeted agent — was trialled in an attempt to reduce his disease burden, it triggered a severe intestinal infection. He developed bloody stools, went into shock, and was admitted to the ICU. His mother received another critical notification.

"The doctors told me there was nothing more they could do," she said. "That I should just accompany him through whatever time he had left."

She did not accept this. Standing in the corridor outside the ICU, she began searching online for information about WAS syndrome and immune deficiency transplantation — looking for any case that resembled her son's. Evidence that someone, somewhere, had faced what they were facing.

She found a specialist at a paediatric haematology centre in Beijing who had shared documented cases of complex transplants — including cases that had failed elsewhere. She reached out. She did not expect a reply.

The specialist replied. After reviewing the details Leo's mother had shared, the response was careful but clear: "There is still hope. We have helped children through third transplants. You can bring him here."

The Journey to Beijing: Harder Than Expected

Getting Leo out of Argentina proved to be its own challenge. Under Argentine regulations, a child in Leo's condition required a physician's signed declaration of fitness to travel before he could board an international flight. His local attending physician refused to sign — worried, reasonably, that Leo might not survive the journey.

His mother escalated through every channel she could access. With support from a local overseas Chinese community organisation and consular assistance, she arranged a remote consultation between the Argentine treating team and the specialist in Beijing — who walked through the proposed treatment plan, the rationale for a third transplant, and the specific steps that would be taken to stabilise Leo before any conditioning began.

The Argentine physician, satisfied that a credible and detailed plan existed, agreed to sign. Leo's mother arranged for a private medical escort — a physician who would accompany them on the flight and manage any in-flight emergency.

On December 21, 2025, Leo and his mother boarded a flight from Buenos Aires to Beijing. The journey covered more than 30,000 kilometres.

Arrival in Beijing: "Like a Lamp About to Go Out"

Leo arrived in Beijing in poor condition. He was severely malnourished from prolonged intestinal disease and extended periods of enforced fasting. He was grey, non-responsive, and had not been eating for weeks. The transplant team later described him as looking like "a lamp about to go out."

The team's assessment confirmed what the records had suggested: his intestinal tract was significantly damaged, and his overall condition was too fragile to proceed directly to transplant conditioning. A careful, stepwise approach would be needed.

The Transplant — and the Bowl of Rice Porridge

The transplant itself proceeded without major complications. In the weeks that followed, Leo developed acute graft-versus-host disease affecting his skin and gut — an expected risk with haploidentical transplants. The team had anticipated this; with prompt management, the GvHD was brought under control within approximately two weeks.

"After everything we had been through, a bit of GvHD felt manageable," his mother said, with a calm that only years of living in hospital corridors could produce.

The milestone that moved her most was not the engraftment confirmation, or the improving blood counts. It was a bowl of rice porridge.

Leo had not been able to eat normally for months before arriving in Beijing. During his recovery, the team introduced food slowly — a few spoonfuls of rice soup, then rice porridge, then small amounts of formula. His mother fed him one spoonful at a time, like feeding a newborn.

When his father returned and saw him — sitting up in bed, eating, talking — the change was enough to speak for itself. "He's a completely different child," his father said.

From "Grey and Silent" to "a Complete Chatterbox"

By April 2026, Leo had been discharged and was attending regular outpatient follow-up. He had gained weight. His colour had returned. His blood results at follow-up had been encouraging, and the family was continuing with the monitoring schedule recommended by the transplant team.

The child who had arrived in Beijing grey, silent, and barely responsive had become — in his mother's words — "a complete chatterbox." He had adopted a capybara soft toy he called "Xiao Pang" (Little Fatty), which he introduced to every member of the medical team who came to check on him.

The family had decided, for the time being, to remain in China. The continuity of follow-up, the familiarity of the team, and the peace of mind it brought them made the decision straightforward.