Mutations of SF3B1 occur in up to 90% of patients with refractory anaemia with unilineage dysplasia (RARS) and 70% of those with refractory cytopenia with multilineage dysplasia and ring sideroblasts or RARS associated with marked thrombocytosis.
Aberrant splicing of genes involved in haemoglobin synthesis and impaired terminal erythroid maturation in SF3B1 mutated refractory anaemia with ring sideroblasts.
Age, JAK2(V617F) and SF3B1 mutations are the main predicting factors for survival in refractory anaemia with ring sideroblasts and marked thrombocytosis.
SF3B1 mutations were found in 55 subjects (53%) including 25 of 39 with refractory anemia and RS (RARS), 26 of 45 (58%) of those with refractory cytopenia with multi-lineage dysplasia and RS (RCMD-RS), 3 of 6 with refractory anemia with excess blasts-1-RS (RAEB1-RS) and 1 of 14 with RAEB2-RS.