Objective      To elucidate the relationship between the single nucleotide polymorphism (SNP) of the asthma immune regulator gene TIM-3 and the susceptibility of childhood cough variant asthma (CVA) in Han population in Chongqing.       Methods      PCR-restriction fragment length polymorphism (RFLP) was used to test the genotypes of the polymorphism loci of Rs1051746

Rs4704853 and Rs10053538 in TIM-3 promoter region among 200 CVA children (CVA group

6.8 years old on average) and 215 controls (control group

5.9 years old on average).       Results      The results of PCR-RFLP showed that the SNP of the Rs1051746 in TIM-3 gene was significantly different between the CVA group and the control group (OR=3.405

95% CI 1.214-9.551

P0.05)

and the frequency of allele T in the CVA group was significantly higher than that in the control group (P0.05)

suggesting the SNP of the Rs1051746 was associated with childhood CVA. The genotype and allele frequencies of the Rs4704853 and Rs10053538 showed no significant difference between the CVA group and the control group

suggesting the SNP of the Rs4704853 and Rs10053538 were not associated with childhood CVA (P0.05). There was statistically significant difference of the haplotype T-C-G between the CVA group and the control group (P0.05)

but the differences of skin prick test (SPT) and the levels of total IgE (TIgE) and eosinophils (EOS) among the CVA children with different genotypes at Rs1051746

Rs4704853 and Rs10053538 were not statistically significant (P0.05).       Conclusion      The SNP of Rs1051746 in the TIM-3 gene is associated with childhood CVA

and the children with haplotype T-C-G may be more likely affected by CVA compared with those without haplotype T-C-G. There may be no relationship between the SNP of Rs1051746

Rs4704853 and Rs10053538 and the levels of SPT

TIgE and EOS.