In conclusion, the functional rs1130866, rs2077079 and rs3024791 polymorphisms in the SP-B gene are not associated with reduced lung function or risk of COPD, making it unlikely that these variants will be useful in personalised medicine.
The test-replication approach identified four genes-microsomal epoxide hydrolase (EPHX1), latent transforming growth factor-beta binding protein-4 (LTBP4), surfactant protein B (SFTPB), and transforming growth factor-beta1 (TGFB1)-that were associated with COPD-related phenotypes.
In the case-control study, the SFTPBThr131Ile polymorphism was associated with COPD, but only in the presence of a gene-by-environment interaction term (P = 0.01 for both main effect and interaction).
The data indicate that SP-B intron 4 variants may associate with increased risk of ARF in COPD and may be used as a marker of susceptibility in this disease subgroup.