Supplementary Material for: Association between Polymorphisms in Bitter Taste Receptor Genes and Clinical Features in Korean Asthmatics

<b><i>Background:</i></b> Bitter taste receptors (TAS2R) in human airway smooth muscle have recently been shown to have an important role in bronchodilation, together with β<sub>2</sub>-adrenergic receptors. <b><i>Object:</i></b> To evaluate the association between genetic variations in <i>TAS2R</i> and clinical features, including bronchodilator response and asthma control. <b><i>Method:</i></b> We analyzed the association between single nucleotide polymorphisms (SNPs) of <i>TAS2R10</i> and <i>TAS2R14</i> and variables such as demographic data, atopy, duration of disease, and asthma control status, including variables such as asthma control test (ACT) score, percent predicted value of forced expiratory volume in 1 s (FEV<sub>1</sub>), forced vital capacity (FVC), and FEV<sub>1</sub>/FVC ratio, as well as bronchodilator response (BDR), in 721 asthma patients in Korea. <b><i>Result:</i></b> Three novel SNPs of 633G>A, 645C>A, and -79G>A in <i>TAS2R10</i> and 3 known SNPs of -815T>C, -1267G>A, and -1897T>C in <i>TAS2R14</i> were analyzed. Increased BDR was significantly associated with SNPs of -815T>C [OR (95% CI) = 1.88 (1.01-3.49), p = 0.04 ] [J Gen Physiol 2005;125:535-553; Am J Respir Cell Mol Biol 2010;42:373-3812], -1267A>G [OR (95% CI) = 2.07 (1.03-4.15), p = 0.04] and -1897T>C [OR (95% CI) = 3.05 (1.01-9.23), p = 0.04, in a dominant model, and OR = 1.91 (1.08−3.36), p = 0.02, in a codominant model] of the <i>TAS2R14</i> gene. There was a significant association between -815T>C and a low mean ACT score [OR (95% CI) = 5.84 (1.94-17.61), p = 0.001]. In haplotype analysis, TAC, CAT, and TGT, or TG and CA haplotypes on <i>TAS2R14</i> were significantly associated with increased BDR; CAT and CA haplotypes were significantly associated with a low ACT score. <b><i>Conclusion:</i></b> Genetic variations in <i>TAS2Rs</i> may be valuable genetic markers to predict therapeutic response and outcomes in asthma. Further research in an independent cohort is needed.