Association Study of Myosin Heavy Chain 15 Polymorphisms with Asthma Susceptibility in Chinese Han

BACKGROUND: The Myosin Heavy Chain 15 gene (MYH15) is expressed in the airway epithelium and variants in the gene have been associated with airway responsiveness. The aim of this study was to perform the first investigation of MYH15 polymorphisms in relation to asthma susceptibility. METHODS: A total of 410 asthma patients and 418 controls from the Chinese Han population were enrolled in the study. Tag-single nucleotide polymorphisms were genotyped and associations between the polymorphisms and asthma risk were analyzed by logistic regression analysis adjusting for confounding factors. Dual-luciferase reporter gene analysis was performed to detect allele-dependent promoter activity of MYH15 variants in HEK293 cells. RESULTS: The A allele of rs9288876 decreased risk of asthma (allelic model: OR=0.808, 95% CI: 0.658-0.993, additive model: OR=0.747, 95% CI: 0.588-0.947, dominant model: OR=0.693, 95% CI: 0.502-0.955). The G alleles of both rs7635009 and rs1454197 were associated with decreased risk of asthma under the additive model (OR=0.779, 95% CI: 0.618-0.981 and OR=0.756, 95% CI: 0.600-0.953, respectively). rs9288876 allele A was associated with higher luciferase activity than allele T (P<0.001). The luciferase activity of rs7635009 allele A was lower than allele G (P=0.001), while rs1454197 allele T had lower luciferase activity than allele G (P<0.001). CONCLUSION: This is the first study to report the association of MYH15 gene polymorphisms with asthma. Polymorphisms of rs9288876, rs7635009, and rs1454197 altered transcriptional regulation of MYH15 and may be functional variants conferring susceptibility to asthma. Further study with larger sample size in different ethnic populations is needed.