Genomic analysis reveals novel allergens of Blomia tropicalis

[Dear Editor,] Blomia tropicalis was considered a storage mite but is now identified as an important species of house dust mite (HDM) and causes a series of allergic diseases, especially in tropical regions such as Singapore. Compared with the major HDM species Dermatophagoides farinae and Dermatophagoides pteronyssinus, B. tropicalis has much fewer reported allergen groups. As an important HDM, B. tropicalis has only fourteen groups of allergens reported in the WHO/IUIS Allergen Nomenclature database, which limits our knowledge to its allergen components. With the advent of omics era, genome-based approaches have been applied to the study of mite allergens. Based on the high-quality genome of B. tropicalis, our genome-wide analysis predicted a comprehensive putative allergen profile of thirty-seven allergen groups (up to group 42), which covered a wide range of allergen homologs. The reported group 19 allergen of B. tropicalis, Blo t 19, could not be found in the genome. Consistent with a previous report, tandem gene duplication caused gene family expansion and result in multiple homologs, such as five tandemly arrayed homologous genes of Blo t 8 (glutathione S-transferase).