Allogeneic Hematopoietic Stem Cell Transplantation in Patients With Myelodysplastic Syndrome Low Risk

Inclusion Criteria: 1. Signed Informed consent 2. Classical IPSS intermediate 1 or low myelodysplastic syndrome associated with at least one poor prognosis feature: 1. Intermediate or higher risk revised IPSS 2. RBC transfusion dependent anemia and failure to 2 or more lines or therapy (including EPO, Lenalidomide or demethylating agent…) 3. thrombocytopenia \< 20 G/L requiring transfusion 4. neutropenia \< 0.5 G/L associated with severe infection (defined as requiring hospitalization) 3. Patient aged ≥ 18 and \< 70 years For young patients, 18-45 years, Fanconi disease and dyskeratosis should be ruled out 4. Patient for whom a transplantation from a matched donor, (8/8 (HLA A, B, C, DRB1) identical at molecular level)unrelated donor or matched sibling), is considered irrespective of donor availability 5. Performance status 0-2 on the Eastern Cooperative Oncology Group (ECOG) Scale (At time of screening) 6. Negative pregnancy and adequate contraception (including in male patients wishing to father), if relevant. 7. Wash-out of at least 30 days since a previous treatment with Vidaza, Lenalidomide, EPO or any other treatment inducing cytopenias. Exclusion Criteria: 1. MDS classified according to classical IPSS as intermediate 2 or High risk 2. Transformation in Acute myeloid Leukemia (AML) 3. Severe active infection or any other uncontrolled severe condition. 4. Organ dysfunctions including the following * Hepatic : total bilirubin \> 2 times upper limit of normal (ULN) (except moderate unconjugated hyperbilirubinemia due to intra medullary hemolysis or Gilbert syndrome) , alanine transaminase (ALT) and aspartate transaminase (AST) \> 3xULN * Symptomatic respiratory chronic failure * Symptomatic cardiac failure * Renal clearance \< 60ml/min 5. Prior malignancy (except in situ cervix carcinoma, limited basal cell carcinoma, or other tumors if not active during the last 3 years) 6. MDS with the following causal germline disease : Fanconi anemia, GATA2 related syndromes and telomere disorders