Abstract: 【Abstract】Objective To determine whether the thromboxane A2 receptor gene T924C polymorphism is associated with the hereditary susceptibility of children asthma as well as the change in lung function and serum specific IgE . Methods This study recruited 125 asthmatic children who were suffering from acute episode and 49 healthy children as control group. Polymerase chain reactions- Restriction fragment length polymorphism (PCR-RELP) techniques were used to detect the TBXA2R SNP. In asthmatic group, serum concentrations of specific IgE antibodies were measured by Allergyscreen. All asthmatic patients who were more than five years old underwent spirometric assessment. Results The distribution frequencies of genotypes (TT,TC,CC) in asthmatic patients were 67,52,6, and the corresponding figures in controls were 38,7,4, there is significant difference between two groups. The frequencies for wild-type(T) and mutant alleles (C) in T924C in our asthmatic patients were 0.744 and 0.256 respectively, and the corresponding figures in controls were 0.8469 and 0.1531. The C alleles frequencies in asthmatic patients are obviously higher than in controls, the difference is significant. The heterozygous genotype(TC) can significantly increase the risk of developing asthma, the OR value (95%CI) is 4.213 (1.741-10.196), p =0.001. The asthmatic patients were divided in two groups (≥3 years of age and＜3 years of age),Compare the genotypes and alleles frequencies in two grups , there is no significant difference. Compare the different items of lung function between TT group and TC+CC group using t-test, there is no statistically significance. Compare the genotypes(TT,TC+CC) distribution and alleles frequencies between sensitization to universal allergens(house dust、house dust mites 、fungi、cat、dog )and no sensitization to them , the p values are all more than 0.05, there is no statistically significance. Conclusion TBXA2R gene T924C polymorphism is associated with the increased genetic susceptibility of developing asthma,the C allele may be susceptibility gene for asthma.The distribution of genotypes doesn’t change with age. The heterozygous genotype (TC) can increase the risk of developing asthma. There is no association between TBXA2R T924C polymorphism and change in lung function or serum sIgE in asthmatic children.

Key words: asthma, children, thromboxane A2 receptor, gene polymorphism, lung function, serum specific IgE