Association between C-589T polymorphisms of interleukin-4 gene promoter and asthma: a meta-analysis.
BACKGROUND
A number of studies of genetic epidemiology have assessed the association of C-589T (also referred to as C-590T; rs number, 2243250) polymorphisms in the promoter region of interleukin-4 (IL-4) gene with asthma in different populations. However, the results are inconsistent and inconclusive.


OBJECTIVE
We performed a meta-analysis of the association between C-589T polymorphisms of IL-4 and asthma with the following objectives: to estimate the magnitude of the gene effect and the possible mode of inheritance.


METHODS
A genetic model-free approach was used to perform a meta-analysis. Asthma (atopy status nondefined), nonatopic and atopic asthma subgroups were separately analyzed. Heterogeneity and publication bias were also explored.


RESULTS
Our meta-analysis summarized the evidence regarding the association between C-589T polymorphisms in the promoter region of IL-4 gene and asthma. When all asthma groups were pooled, a significant association of increased asthma risk and T allele was found. In subgroup analysis, our results indicated a significant association and a recessive genetic mode of C-589T polymorphisms of IL-4 with atopic asthma. The CC genotype was about 21 percent less likely to have atopic asthma than the genotype CT and TT. However, C-589T polymorphisms were not significantly associated with nonatopic asthma.


CONCLUSIONS
This meta-analysis suggests there may be an important effect of single nucleotide polymorphisms (SNPs) in the promoter region of IL-4 gene on the pathogenesis of atopic asthma. This warrants further investigation in larger studies and meta-analysis.
Li
Yafei
Y
Department of Epidemiology, College of Preventive Medicine, Third Military Medical University, Chongqing 400038, PR China. yafeilye@yahoo.com.cn
Guo
Botao
B
Zhang
Lin
L
Han
Jiaxin
J
Wu
Bo
B
Xiong
Hongyan
H
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001249:Asthma / Q000453:epidemiology / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics; D005838:Genotype; D006801:Humans; D015847:Interleukin-4 / Q000235:genetics* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics*; D019948:Receptors, Interleukin-4 / Q000378:metabolism
D019948:Receptors, Interleukin-4; D015847:Interleukin-4