NFE2L2 gene variants and susceptibility to childhood-onset asthma.

INTRODUCTION Environmental factors causing oxidative stress are known to be associated with asthma morbidity. The antioxidative gene NFE2L2 has been implicated in asthma development in mice models. In humans, the SNPs -617C/A and -653G/A, located at the promoter region of NFE2L2 gene, have been found associated with the susceptibility to develop diverse chronic-degenerative diseases. OBJECTIVE To determine if there is association of the -617C/A and -653G/A NFE2L2 SNPs and childhood-onset asthma in a Mexican population. MATERIALS AND METHODS In a case-control study 242 unrelated patients with diagnosis of asthma and 358 ethnically- and sex-matched healthy individuals were included. The -617C/A and -653G/A NFE2L2 genotyping was carried out using the TaqMan allelic discrimination assay. RESULTS The risk allele of both polymorphisms showed a high frequency in our sample (-617A: 24% and -653A: 40%), similarly to those previously reported in Asiatic populations (-617A: 24-29% and -653A: 42-52%; p > 0.05). In contrast, the -617A allele frequency was higher than that reported in a European-African admixed population (10%, p < 0.001). The allelic and genotypic frequencies from both polymorphisms showed no significant differences among cases and controls in female and male samples. Likewise, haplotype analysis found no association between NFE2L2 gene variants and the disease. CONCLUSIONS Despite the experimental evidence suggesting that NFE2L2 gene is involved in asthma pathogenesis, the -617C/A and -653G/A SNPs were not associated with childhood-onset asthma.