A 9 month old presents with hepatosplenomegaly, pallor and a…

A 9 month old presents with hepatosplenomegaly, pallor and a slight arrythmia.Hgb:          6.1 g/dLMCV      65.5 fLMCHC:   30.5 g/dLRDW:     25.0Hemoglobin electrophoresis shows 0% A, 3% A2 and 97% F.  What condisiton is most likely causing the hematolgic abnormalities?