Occurrence of myelodysplastic syndrome in 2 patients with reticular dysgenesis.

摘要

Reticular dysgenesis (RD) is an autosomal recessive disease that accounts for 3% of all severe combined immunodeficiencies.1 At birth, this disease is characterized by the absence of neutrophils, T cells, and natural killer lymphocytes and a slight decrease in red blood cell, platelet, and B-cell counts. The red blood cell lineage corrects spontaneously with age. It is noteworthy that RD also affects the inner ear and leads to profound sensorineural deafness. The gene responsible for RD encodes the adenylate kinase 2 (AK2) protein,2'3 a ubiquitous enzyme that induces the reverse transphosphorylation of AMP and ATP molecules into adenosine diphosphate.4 Allogeneic he-matopoietic stem cell transplantation (HSCT) can correct hema-topoiesis, demonstrating that the defect in RD is intrinsic and not microenvironmental. Herein we describe 2 patients affected by RD who had myelodysplastic syndrome (MDS) 3 and 6 years, respectively, after partially successful HSCT that led to split chimerism.