The association between living <200 m from a major road and current asthma and wheeze was more marked for carriers of the <i>GSTT1</i> null and <i>GSTP1 val</i>/<i>val</i> or <i>ile</i>/<i>val</i> genotypes.
Few studies evaluated wheezing and BHR and most reported no associations, although weak evidence was found for positive associations of GSTM1 null and GSTP1 Val allele with wheezing and a negative association of GSTP1 Val allele with BHR.
Variants in both the promoter and coding regions of the GSTP1 locus may contribute to the occurrence of childhood asthma and wheezing and may increase susceptibility to adverse effects of tobacco-smoke exposure.
Children carrying any GSTP1 Val-105 allele were at a significantly greater risk of both ever and current wheezing when exposed to ETS, with a clear dose-response relationship to the number of smokers at home.
To investigate the association of TNF G-308A with asthma and wheezing and to determine whether these associations vary with ozone exposure and GSTM1 and GSTP1 genotype.