LAUSR

X‐linked agammaglobulinemia (XLA) is a primary antibody disorder due to a mutation in the Bruton tyrosine kinase gene that requires lifelong immunoglobulin replacement resulting in a significant economic burden and treatment abandonment. Hematopoietic stem cell transplantation (HSCT) offers an alternative option for complete cure. In our series, two children with XLA underwent successful HSCT using a myeloablative conditioning with thiotepa, treosulfan, and fludarabine from a matched sibling donor. The second child had rejected his first graft following a busulfan‐based regimen with resultant autologous reconstitution. At 6 months post‐HSCT, serum IgG were normal, off IVIG, and had no infections. Both children after a median follow‐up of 20 months have 100% chimerism. Treosulfan‐based reduced toxicity myeloablative HSCT has encouraging results with a positive impact on the socioeconomics in developing countries.