The role of IFIH1 gene rs1990760 and rs2111485 single-nucleotide polymorphisms in generalized vitiligo predisposition

Association of rs4711998 of IL-17A, rs2275913 of IL-17A and rs763780 IL-17F gene polymorphisms with non-segmental vitiligo in a Mexican population

Vitiligo is the most common depigmenting disease characterized by achromic macules due to selective loss of melanocytes. The pathogenesis remains poorly elucidated, and multiple hypotheses exist regarding its pathogenesis. Evidence suggests that stress on melanocytes can result in activation of the immune system, and involvement of both activated cluster of differentiation (CD8+) cytotoxic and CD4+ T cells in the dysfunction, depigmentation, and apoptosis of melanocytes. Recent studies show that the interleukin 17 (IL-17) axis plays a central role in the pathogenesis of the disease. IL-17 is an important regulatory effector cytokine in this pathway. The aim of this study was to evaluate the association of IL-17A rs4711998 (-832A/G), IL-17A rs2275913 (-197G/A), and IL-17F rs763780 (7488A/G) with vitiligo in a Northeastern Mexican population. This was a case-control study and included 116 patients with vitiligo and 116 control subjects. Genotype characterization of IL-17A rs4711998 (-832A/G), IL-17A rs2275913 (-197G/A), and IL-17F rs763780 (7488A/G) was performed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. A p ≤ 0.05 was considered significant. It was observed that the combination of the genotypes GG/GA for IL-17F rs763780 (7488A/G) was associated with an increased risk for the development of vitiligo (OR 2.0943, 95% Cl 1.2375-3.5445, p = 0.0056). Regarding IL-17A rs4711998 (-832A/G) and IL-17A rs2275913 (-197G/A) genotyping, no association with vitiligo development was found. In conclusion, the SNP rs763780 in the IL-17F gene appears to be a risk factor for vitiligo development in this Mexican population and it may be useful in future studies, especially for the development of new therapies.

Association Among MIF, IFIH1, and IL6 Gene Polymorphisms and Non-Segmental Vitiligo in a Chinese Han Population

Objective

The aim of the present study was to investigate the association of single-nucleotide polymorphisms (SNPs) in the macrophage migration inhibiting factor (MIF), interferon-induced Helicase C domain 1 (IFIH1), interleukin-6 (IL6) genes, circulating levels with non-segmental vitiligo (NSV) susceptibility in the Chinese population, and to analyze the relationships between gene polymorphisms and clinical characteristics of vitiligo.

Methods

In this study, genotyping was conducted in 155 patients with NSV and 117 unaffected controls using polymerase chain reaction and snapshot technique. Serum concentrations were determined by ELISA kit.

Results

There were strong associations between IFIH1 H843R and IL6-572G/C polymorphisms and NSV susceptibility (p = 0.013; p = 0.009). In contrast to previous studies, we found no significant difference in the MIF-173G/C polymorphism between the two groups. In addition, the frequency of allelic distribution for MIF-173G/C in patients with active NSV was significantly higher than stable NSV (p = 0.011), and IFIH1 H843R with early-onset (≤ 20), active or family history of NSV was significantly higher than late-onset (> 20), stable or no family history of NSV (p = 0.033; p = 0.045; p = 0.039). Serum concentrations of MIF were higher in patients with active NSV, serum IFIH1 and IL6 concentrations were related to the presence of polymorphisms in patients with NSV (p = 0.009; p = 0.011).

Conclusion

Our results suggested that IFIH1 H843R and IL6-572G/C gene polymorphisms and expression levels are obviously correlated with the onset of NSV. MIF-173G/C allele and serum concentrations may be associated with active NSV, and IFIH1 H843R allele may be associated with youth, active or family history of NSV.