Open AccessAllele‐specific transcriptional activity of the variable number of tandem repeats of the inducible nitric oxide synthase gene is associated with idiopathic achalasia
Author(s) -
Sarnelli Giovanni,
Grosso Michela,
Palumbo Ilaria,
Pesce Marcella,
D’Alessandro Alessandra,
Zaninotto Giovanni,
Annese Vito,
Petruzzelli Raffaella,
Izzo Paola,
Sepulveres Rossana,
Bruzzese Dario,
Esposito Giuseppe,
Cuomo Rosario
Publication year - 2017
Publication title -
ueg journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.667
H-Index - 35
eISSN - 2050-6414
pISSN - 2050-6406
DOI - 10.1177/2050640616648870
Subject(s) - allele , variable number tandem repeat , tandem repeat , achalasia , microbiology and biotechnology , nitric oxide synthase , pathogenesis , genotyping , nitric oxide , gene , allele frequency , medicine , promoter , biology , genotype , genetics , immunology , gene expression , esophagus , genome
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 both in immune function and inhibitory neurotransmission. Objective The objective of this article is 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 < 0.05). Long repeats were also significantly associated with an earlier onset of the disease (OR 1.69, 95% CI 1.13–2.53, p = 0.01). Transfection experiments revealed a similar allele‐specific iNOS transcriptional activity. Conclusion The functional polymorphism (CCTTT) of NOS2 promoter is associated with achalasia, likely by an allele‐specific modulation of nitric oxide production.