Association of polymorphisms of STAT6 and SO(2) with Chinese childhood asthma: a case-control study.

OBJECTIVE To investigate the association of polymorphisms of STAT6 gene and air pollutants of PM(10), NO(2), and SO(2), with asthma in Chinese children. METHODS 418 subjects aged 14 years and under were recruited in a case-control study. The association between STAT6 polymorphisms and childhood asthma were tested by allele frequency, genotype analysis, and MDR analysis. Exposure to outdoor air pollutants was estimated by a 5-day moving average level. Statistical analyses were performed with SAS 9.1 software. RESULTS Only 3 alleles of GT repeats at exon 1 of STAT6 were found in Chinese children. C258T and T710C were 2 new SNPs of STAT6 at 3'-UTR. Children who carried T allele of C258T were more common in asthma children than in control subjects (P<0.05). The MDR analysis showed that GT repeats, C258T and T710C of STAT6 polymorphisms interacted together in leading to susceptibility to childhood asthma among Chinese people. After confounding factors were controlled, such as SNP C258T, family history of asthma, frequency of influenza within a year, the 5-day average of SO(2) was tested to be a key risk factor of asthma in Chinese children (P<0.05). CONCLUSION Chinese children differed in polymorphisms of STAT6 and in its relation with childhood asthma.