Polymorphism in the Vitamin D Receptor Gene Decreases the Risk of Perianal Fistulas in Crohn's Disease
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Background: Vitamin D, through the activation of its receptor (VDR), plays an immunomodulatory role in the gastrointestinal tract. Single-nucleotide polymorphisms (SNPs) in the VDR gene have been associated with Crohn's disease (CD) risk, and patients carrying the polymorphism in this gene run a higher risk of developing a penetrating behavior.
Aims: We analyzed the association of , , , and SNPs in the gene with the clinical characteristics of CD.
Methods: Four polymorphisms identified in the gene (, , , and ) were genotyped in blood samples from CD patients (n = 115) by using PCR-RFLP. The disease's location and behavior and the presence of perianal fistulas were collected from each patient. Intestinal fibroblasts from ileal resections of CD patients (n = 10) were genotyped, and the expression of fibrotic and inflammatory markers was analyzed by RT-PCR.
Results: The data reveal no association between any of the polymorphisms and CD risk. A strong linkage disequilibrium was detected between and both and , which in turn were strongly associated. Homozygosis or heterozygosis for the a allele of the SNP or b allele of the SNP was significantly associated with a lower risk of a penetrating behavior, while the aa genotype was associated with a lower risk of perianal fistulas. Fibroblasts carrying the aa genotype expressed lower levels of fibrotic and inflammatory markers.
Conclusion: The aa genotype of the SNP in the gene is associated with a lower risk of perianal fistulas in CD and a reduced expression of fibrotic and inflammatory markers in intestinal fibroblasts.
Kafentzi T, Tsounis E, Tourkochristou E, Avramopoulou E, Aggeletopoulou I, Geramoutsos G Int J Mol Sci. 2025; 26(5).
PMID: 40076474 PMC: 11899612. DOI: 10.3390/ijms26051848.