Association of TIM4 promoter polymorphism −1419G>A with childhood asthma in a Chinese Han population

TIM4, which is expressed on dendritic cells and macrophages, plays an important role in the proliferation of T helper type 2 (Th2) cells. Asthma, as a complex genetic disease, is thought to arise from the development of a Th2‐lymphocyte‐predominant immune response. To evaluate the effects of the promoter polymorphisms (‐1419G>A and ‐1609G>A) in TIM4 on asthma susceptibility, case‐control and family‐based association studies were conducted by polymerase chain reaction and restriction fragment length polymorphism. Our results showed that TIM4 ‐1419G>A polymorphism was associated with asthma susceptibility in our study population (χ2= 9.88, P < 0.001, OR = 1.91, 95% CI 1.37–2.64). The ‐1419A/A and ‐1419A/G genotypes were observed more common in asthmatic group (6.3%, 41.8%) than in control group (1.7%, 29.3%). No significant difference was found in genotype and allele frequencies of TIM4 ‐1619G>A polymorphism between asthmatic and control groups. No association between the two SNPs and total serum IgE levels, lung function was observed. In conclusion, the present findings suggest that TIM4 ‐1419G>A polymorphism might be the genetic factor for the risk of childhood asthma in Chinese Han population.