Strong association between the -308 TNF promoter polymorphism and allergic rhinitis in pakistani patients

Background: Allergic rhinitis (AR) is a common complex allergic inflammatory disorder. The tumor necrosis factor (TNF) α polymorphism G-308A is present in the promoter region of the gene and considered to be important due to its role in different allergic diseases. Objectives: We aimed to identify genetic associations between this polymorphism and AR in patients of Pakistani origin. Methods: We analyzed the distribution of G-308A in 153 unrelated AR patients and 116 unrelated healthy controls. Samples were genotyped for G-308A using restriction fragment length polymorphism. Results: The TNF -308A allele (TNF2) was significantly more frequent in patients with AR (37%) than in controls (16%, P<.001; χ2=32.15). Genotype distribution was also significantly different between patients and controls (P<.001; χ2=40.81). The TNF2 homozygous genotype and TNF1/2 heterozygous genotype were significantly more common in AR patients (TNF2, 12%; TNF1/2, 49%) than in controls (TNF2, 4%; TNF1/2, 23%), whereas the normal TNF1 homozygous genotype was more frequent in controls (73%) than in patients (39%). Conclusion: Our results suggest a strong association between the promoter polymorphism of TNF-α and AR in Pakistani cohorts.