The transplant was led by Dr. M. Deenadayalan, Head of the Department of Paediatric Haematology, Oncology, Blood and Marrow Transplantation.
Published Aug 20, 2025 | 6:22 PM ⚊ Updated Aug 20, 2025 | 6:22 PM
Representational image. Credit: iStock
Synopsis: The procedure was a TCR alpha beta depleted haploidentical bone marrow transplant, in which immune cells that could cause rejection are removed from the donor’s stem cells to make the transplant safer.
In a breakthrough for pediatric transplantation, doctors at Chennai’s MGM Cancer Institute have saved the life of a 12-year-old girl with Bloom Syndrome – a rare genetic disorder – by performing a complex half-matched bone marrow transplant using stem cells from her younger brother making it the world’s first documented successful case of this kind of transplant in a child.
The girl, who hails from Chennai, was diagnosed with Bloom Syndrome at the age of 10. Her condition carried a high risk of developing blood cancer and was further complicated by additional bone marrow abnormalities.
With her health deteriorating, doctors decided that a bone marrow transplant was the only way to save her life. After the procedure, she has recovered fully, marked one year since the transplant, and is now attending school and taking part in daily activities like other children her age.
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MGM Cancer Institute said the achievement is a significant step forward in tackling some of the rarest and most challenging pediatric conditions. The transplant has been recognised internationally, with the case being published in Pediatric Blood and Cancer, a leading peer-reviewed journal in pediatric hematology and oncology, for its global clinical importance.
What is Bloom Syndrome?
Bloom Syndrome is a rare inherited condition that increases vulnerability to cancers and bone marrow failure. In the case of this patient, the syndrome was made more complicated by Monosomy 7, a chromosomal abnormality where one copy of chromosome 7 is missing, and Myelodysplastic Syndrome (MDS), a disorder in which the bone marrow cannot produce healthy blood cells.
Doctors said the combination of these factors created an imminent risk of her MDS progressing to leukemia, a type of blood cancer in which abnormal white blood cells grow uncontrollably. This made a bone marrow transplant urgent and unavoidable.
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According to the doctors, finding a matching donor was a major obstacle. A worldwide search revealed no fully matched family or unrelated donors, and both parents were identified as carriers of the same genetic mutation. Genetic evaluation showed that her younger brother did not carry the mutation, making him the best candidate for donation.
His younger age and smaller body size, however, meant that the standard stem cell collection protocol, the medical process used to harvest stem cells, had to be modified to safely obtain an adequate dose without risk to him.
At the same time, the medical team had to adapt the patient’s preparatory regimen. Children with Bloom Syndrome are known to be highly sensitive to chemotherapy. This ruled out standard high-dose regimens, forcing the doctors to carefully design a modified conditioning protocol, a customised combination of medicines given before the transplant to prepare the body to accept the donor’s cells. These modifications required meticulous planning and coordination across specialties.
Child fully recovered
The procedure was a TCR alpha beta depleted haploidentical bone marrow transplant, in which immune cells that could cause rejection are removed from the donor’s stem cells to make the transplant safer.
The transplant was led by Dr. M. Deenadayalan, Head of the Department of Paediatric Haematology, Oncology, Blood and Marrow Transplantation.
“Bloom Syndrome is extremely rare, and combined with Monosomy 7 and MDS, it is almost unheard of. Only a handful of such cases exist in global literature,” he said.
He added that the girl has achieved 100% donor chimerism, meaning all her blood cells are now produced by the donor’s stem cells, a key marker of success in bone marrow transplantation.
The patient has now completed one year since the transplant with full immune recovery. Doctors said she will continue to undergo regular follow-up to track her long-term health, but the successful outcome demonstrates what can be achieved through precision medicine and teamwork.
“This case shows that with careful planning and expertise, even the most challenging pediatric transplants are possible,” Dr. Deenadayalan said.
(Edited by Amit Vasudev)
