Allergy-associated polymorphisms of the Fc epsilon RI beta subunit do not impacts two amplification functions

Two variants of the beta-chain of the high affinity IgE receptor Fc epsilon RI, I181L-V183L and E237G, have been found associated with allergy. We hav e previously shown that the beta-chain plays at Last two distinct amplifier functions. It amplifies Fc epsilon RI surface expression and signaling, re sulting in an estimated 12- to 30-fold amplification of downstream events. To test the hypothesis that the I181L-V183L and E237G beta variants may be functionally relevant and could directly contribute to an allergic phenotyp e, we have evaluated the functional impact of the beta variants on the two amplifier functions of beta. We found that these variants have no direct ef fect on the beta amplifier functions. However, the possibility remains that these variants are in linkage disequilibrium with other more relevant poly morphisms or are affecting unknown beta-chain functions.