Successful Haploidentical Bone Marrow Transplantation of an Infant With a Novel Mutation in SAMD9L Gene (Ataxia-Pancytopenia Syndrome).

Data regarding the outcomes of hematopoietic stem cell transplant (HSCT) for the management of SAMD9L -associated ataxia-pancytopenia syndrome remains limited. We depict the case of a 2-month-old male with a novel mutation in the SAMD9L gene, presenting with respiratory failure, pancytopenia and severe developmental delay. He experienced graft failure 2 months after a 4/6 HLA-matched cord HSCT. At 9 months old, an unsuccessful unrelated donor search prompted a haploidentical HSCT with successful engraftment. He sustains excellent donor chimerism and has improved developmentally over 2 years posttransplant. This case demonstrates haploidentical HSCT as a viable option for patients with SAMD9L mutation and no acceptable unrelated donor.