Supplementary Material for: Association of the –1072G/A Polymorphism in the <b><i>LTC4S</i></b> Gene with Asthma in an Indian Population

<b><i>Background:</i></b> Atopic asthma, the most common chronic disease affecting children and young adults, is a complex disorder with variable phenotypes. Cysteine leukotrienes (Cys-LTs) are powerful bronchoconstrictors and play a critical role in airway inflammation and remodeling that are characteristic of asthma. <b><i>Objective:</i></b> To investigate the association of <i>ALOX5</i>, <i>LTC4S </i>and<i> CysLTR2 </i>gene polymorphisms with atopic asthma in an Indian population. <b><i>Methods:</i></b> A total of 19 single nucleotide polymorphisms (SNPs) within these genes were genotyped in a family-based cohort (n = 239) and a case-control cohort (139 cases and 194 controls) followed by association analyses. <b><i>Results:</i></b> We found a significant association of the –1072G/A (rs3776944) SNP with atopic asthma in the family-based association analysis (p = 0.0004). These results were also replicated in the case-control cohort (p = 0.009). The allele A was negatively associated with atopic asthma. We also noted a significant association in the two-locus (rs3776944G/A and rs730012A/C) haplotypic analysis of this gene both in the family-based (p = 0.03) and the case-control (p = 0.02) analyses. <b><i>Conclusion:</i></b> This study supports the role of the <i>LTC4S </i>gene polymorphism in genetic susceptibility to atopic asthma in an Indian population