ALLELE-SPECIFIC TRANSCRIPTIONAL ACTIVITY OF THE VARIABLE NUMBER OF TANDEM REPEATS OF THE INDUCIBLE NITRIC OXIDE SYNTHASE GENE IS ASSOCIATED WITH IDIOPATHIC ACHALASIA

Background: Polymorphisms of genes involved in the regulation of the immune response are risk factors for achalasia, but their contribution to disease pathogenesis is unknown. Nitric oxide is involved in both immune function and inhibitory neurotransmission. Objective: to assess the association and the functional relevance of the CCTTT inducible Nitric Oxide Synthase (NOS2) gene promoter polymorphism in achalasia. Methods: Genomic DNA was isolated from 181 achalasia patients and 220 controls. Genotyping of the (CCTTT)n repeats was performed by PCR and capillary electrophoresis, and data analyzed by considering the frequency of the different alleles. HT29 cells were transfected with iNOS luciferase promoter-reporter plasmids containing different (CCTTT)n. Results: The alleles’ distribution ranged from 7 to 18, with a peak frequency at 12 repeats. Analysis of the allele frequencies revealed that individuals carrying 10 and 13 CCTTT repeats were respectively less and more frequent in achalasia (OR 0.5, 95% CI 0.3-0.5 and OR 1.6, 95% CI 1-2.4, all p