030 and 0.039, respectively); FEV1/FVC increased by 0.034 and 0.021 per the minor G allele was present. Table 4 indicates the associations between the SNPs in the ALOX5AP and FEV1 or FEV1/FVC. This study is unique because most studies examining associations between genetic variation and diseases, including lung-related diseases, have focused on patient populations rather than healthy population. Healthy population-based studies such as the present one are important because they

may facilitate disease prevention, which is more effective than treating diseases once they have developed. The ALOX5AP gene participates in the 5-LO pathway, which is known PD332991 to play a role in several disease processes [20]. The present study analysed the effect of this gene on the lung functions of pulmonary disease-free Koreans and all Korean in cohorts. Several genotypes were found to associate significantly with the baseline lung function FEV1. Interestingly, no SNP was associated with FEV1 in Ansan but there were several identical SNPs, rs10162089, rs3803277 and rs9506352, associated with FEV1 in Ansung and combined data in both healthy and general Galunisertib in vitro population. From that, it was assumed that those SNPs associated with FEV1 affects the lung function level and development of respiratory diseases such as asthma and chronic lung disease may be indirectly

influenced. A previous case–control study revealed that the ALOX5AP gene was not associated with FEV1 in aspirin aminophylline acetylsalicyclic

acid-intolerant asthma [21]. Polymorphism of the ALOX5AP gene promoter was also found not to affect the development of asthma in Australian and Caucasian populations [22, 23]. However, Holloway et al. [24] have identified associations between ALOX5AP SNPs and asthma-related phenotypes such as FEV1, total IgE, atopy and bronchial hyper-responsiveness, although Klostman et al. [25] found that ALOX5AP genetic variation did not affect the response of patients with asthma to montelukast, which is a leukotriene modifier. These two studies did not find an association between rs3803277 and FEV1 or other phenotypes. In contrast, the present study revealed a significant (P < 0.05) association between rs3803277 and FEV1 in general population; this association remained significant after permutation testing. The 5-LO pathway is also associated with chronic rhinosinusitis and various cardiovascular diseases [26]. The polymorphisms at position (-1072)G>A and (-444)A>C of the LTC4 synthase were associated with increased risk of transient ischaemic attack and ischaemic stroke but not associated with asthma and COPD in Danish general population [27]. Helgadottir et al. [28] found two ALOX5AP halotypes, HapA and HapB, which play critical roles in the development of myocardial infarction and stroke.