Abstract
While a majority of patients with refractory anemia with ring sideroblasts and thrombocytosis harbor JAK2V617F and rarely MPLW515L, JAK2/MPL-negative cases constitute a diagnostic problem. 23 RARS-T cases were investigated applying immunohistochemical phospho-STAT5, sequencing and SNP-A-based karyotyping. Based on the association of
TET2/
ASXL1 mutations with MDS/MPN we studied molecular pattern of these genes. Two patients harbored
ASXL1 and another 2
TET2 mutations. Phospho-STAT5 activation was present in one mutated
TET2 and
ASXL1 case. JAK2V617F/MPLW515L mutations were absent in
TET2/
ASXL1 mutants, indicating that similar clinical phenotype can be produced by various MPN-associated mutations and that additional unifying lesions may be present in RARS-T.
