Coding SNP in tenascin-C fn-III-D domain associates with adult asthma

The extracellular matrix glycoprotein tenascin-C (TNC) has been accepted as a valuable histopathological subepithelial marker for evaluating the severity of asthmatic disease and the therapeutic response to drugs. We found an association between an adult asthma and an SNP encoding TNC fibronectin type III-D (Fn-III-D) domain in a case–control study between a Japanese population including 446 adult asthmatic patients and 658 normal healthy controls. The SNP (44513A/T in exon 17) strongly associates with adult bron-chial asthma (x2 test, P 5 0.00019, Odds ratio 5 1.76, 95 % confidence interval5 1.31–2.36). This coding SNP induces an amino acid substitution (Leu1677Ile) within the Fn-III-D domain of the alternative splicing region. Computer-assisted protein structure modeling suggests that the substituted amino acid locates at the oute