First Successful Allogeneic Hematopoietic Stem Cell Transplantation for MKL1 Deficiency

Excerpt

Megakaryoblastic leukemia 1 (MKL1) deficiency was recently identified as a human primary immunodeficiency, due to a pronounced actin polymerization defect and impaired chemotactic response of neutrophils resulting in cytoskeletal dysfunction of predominantly phagocytes. So far, three patients, including two siblings, have been reported with mutations in the MKL1 gene, leading to this severe immunodeficiency with increased susceptibility to predominantly severe bacterial infections (mainly Pseudomonas) as well as poor wound healing and thrombocytopenia (1, 2). Allogeneic hematopoietic stem cell transplantation (HSCT) is, as yet, the only curative option to restore this innate immunity defect. Here, we report the first successful pre-emptive HLA-identical HSCT in an infant with MKL1 deficiency. This case has previously been shortly mentioned in the manuscript by Sprenkeler et al. (2). We now provide a detailed report of the HSCT procedure and follow-up for this patient. …