Surprisingly, employing models of passive and active IgE-mediated anaphylaxis, we show that diminished GATA-1 functionality has no impact on IgE-MC-dependent responses in the naïve state, however, antigen sensitization models revealed that low GATA-1 activity amplifies IgE-MC-dependent responses and that the increased response appeared to be associated with a stronger pro-Type 2 response associated with increased antigen-specific IgE and CD4+ Th2 response. This evidence concerns the gene IGHE and anaphylaxis.