Clinical characteristics of patients with the SAMD9/SAMD9L gene defects

Conditions associated with defects in the SAMD9/SAMD9L genes represent a relatively new group of diseases characterized by a diverse range of clinical manifestations: from multisystem disorders such as MIRAGE syndrome to isolated hematological manifestations. A previous history of infectious diseases in patients with SAMD9/SAMD9L gene defects before the onset of hematological manifestations is in most cases associated with the defects of the immune system. Gain- or change-of-function germline mutations in the SAMD9/SAMD9L genes are the most common predisposition factors for pediatric myelodysplastic syndrome (MDS) with monosomy 7. However, SAMD9/SAMD9L patients with cytogenetic rearrangements but without any signs or symptoms of MDS can have spontaneous remission due to various compensatory cellular mechanisms. The presence of primary immunodeficiency and a predisposition to MDS at an early age requires a more detailed approach to this group of patients and early determination of indications for allogeneic hematopoietic stem cell transplantation. The patients’ parents gave their consent to the use of their child’s data, including photographs, for research purposes and in publications.