Genetic polyymorphisms that result in three amino acid changes in Fc epsilon RI beta chain (Ile(181)--> Leu, Val(183)--> Leu, and Glu(237)--> Gly) have been identified as candidates that associate with allergic disorders such as atopy and asthma. To elucidate the biological significance of these polymorphisms in regulating the expression and function of Fc epsilon RI, we generated four types of transfectants that express wild-type or mutant mouse beta chains corresponding to these human variants by retrovirus-mediated gene transfer into beta chain-deficient mouse-derived mast cells. No significant functional differences between the wild-type beta chain transfectant and any of the mutant beta chain transfectants were observed in beta-hexosaminidase release, intracellular calcium mobilization, or cytokine and leukotriene C-4 production in response to Fc epsilon RI crosslinking. Our results suggest that these polymorphisms in Fc epsilon RI beta chain do not affect Fc epsilon RI-mediated mast cell activation at least in our mouse in vitro system.