Endothelial nitric oxide synthase gene polymorphisms are associated with sensitization to seasonal aeroallergens in asthmatic children

Maria Iordanidou, Emmanouil Paraskakis, Anna Tavridou, Athanasios Chatzimichael, Vangelis G. Manolopoulos

Childhood asthma phenotype is the consequence of interaction between environment and genetic factors. Nitric oxide (NO) formation is affected by polymorphisms in nitric oxide synthase (NOS) enzymes, which play a significant role as inflammatory factors in the airways. This study was undertaken to estimate the correlation of -786C>T and 894G>T polymorphisms of the eNOS gene with the sensitization of asthmatic children to common aeroallergens. A total of 193 asthmatic children and 96 healthy controls, who were of Mediterranean origin, living in the same geographical area, were enrolled in the study. 894G>T and -786T/C polymorphisms of the eNOS gene were analyzed using a PCR-RFLP method. The 894GG genotype was more frequent (68.6%) in children with asthma sensitized to Oleaeuropaea than in those with asthma non-sensitized (43.0%) (P=0.004). Likewise, -786TT genotype frequency was higher in children with asthma sensitized to Oleaeuropaea (51.0%) than in those with asthma nonsensitized (31.7%) to this allergen (P=0.035). For the aeroallergens Parietariajudaica and mixed grass, the frequency of -786C allele carriage was associated with protection from sensitization to Parietariajudaica and mixed grass in asthmatic children (P=0.021 and P=0.017, respectively). In the healthy control group, the genotype frequencies for these polymorphisms were similar to genotype frequencies of children with asthma nonsensitized to these three specific aeroallergens. In children with asthma, 894G>T and -786T/C polymorphisms of the eNOS gene were correlated with sensitization to common seasonal aeroallergens.