309 FREQUENCY AND PROGNOSTIC IMPACT OF SF3B1 AND DNMT3A MUTATIONS IN REFRACTORY ANEMIA WITH RING SIDEROBLASTS (RARS). Issue 1 (April 2015) - Martín, I.; Such, E.; Vicente, A.; Navarro, B.; López-Pavía, M.; Gómez, M.; Ibáñez, M.; Tormo, M.; Oltra, S.; Cervera, J.; Sanz, G.