Analysis of the association between the T113M polymorphism of the human interleukin 9 gene and bronchial asthma

The T113M polymorphism resulting from the missense mutation in exon 5 of th e human gene for interleukin 9 (IL9) was tested for association with bronch ial asthma (BA). The genotype frequency analysis did not reveal a deviation from the Hardy-Weinberg equilibrium. A comparison of the genotype frequenc y distributions in a control group of healthy individuals and in patients w ith BA suggested an association between T113M and the clinical phenotype. H owever, this association was not confirmed by the affected family-based ass ociation control (AFBAC) or the transmission/disequilibrium test (TDT).