Abstract: A novel TH2 associated gene that is induced by IL-9 has been identified and isolated, thereby providing a therapeutic target for IL-9 mediated diseases such as atopic allergy and asthma-related disorders. The invention also includes methods for the identification and use of small molecule inhibitors of this gene and its products to treat these disorders, methods for diagnosing susceptibility to, and assessing treatment of atopic allergy or asthma-related disorders by measuring the level of gene expression in biologic samples using antibody specific for this protein. The use of this protein as a therapeutic agent for the treatment of autoimmune diseases is also indicated.

Abstract: A C to T DNA variation at position 3365 in exon 5 of the human Asthma Associated Factor 1 (AAF1) produces the predicted amino acid substitution of a methionine for a threonine at codon 117 of AAF1. When this substitution occurs in both alleles in one individual, it is associated with less evidence of atopic allergy including asthma, fewer abnormal skin test responses, and a lower serum total IgE. Thus, applicant has identified the existence of a non-asthmatic, non-atopic phenotype characterized by methionine at codon 117 when it occurs in both AAF1 gene products in one individual.