Loss-of-function mutations in the gene encoding filaggrin underlie a Japanese family with food-dependent exercise-induced anaphylaxis

Background: Food-dependent exercise-induced anaphylaxis (FDEIA) is a serious food allergy in which anaphylaxis develops when exercise is performed within several hours after food intake. The precise mechanism underlying allergic sensitization in FDEIA has been an important issue but remains poorly understood. Objectives: We aimed to elucidate the pathomechanism including the route of allergen sensitization involved in FDEIA. Methods: A Japanese family with wheat-dependent exercise-induced anaphylaxis (WDEIA), a specific form of FDEIA, were clinically examined. Mutation analysis of the gene encoding filaggrin (FLG) was also performed. Results: Two of the family members were confirmed as WDEIA on the basis of their medical history and positive provocation test results. Notably, the two affected individuals in the family had concomitant ichthyosis vulgaris. Mutation analysis of FLG revealed that they carry one or more loss-of-function mutations that have not been described in the Japanese population. Conclusion: These results indicate that FLG mutations might be involved in the pathogenesis of WDEIA in the present case.