We investigated whether the tumor necrosis factor-a (TNF-α) promoter -238 A/G and -308 A/G polymorphisms are associated with rheumatoid arthritis (RA) and vitiligo susceptibility.
The frequency of allele A (TNF-α 2-allele) was significantly higher and that of allele G (TNF-α 1-allele) was lower in vitiligo patients compared to controls, indicating an association of allele A with susceptibility to vitiligo in Saudi patients.
Data for a total of 1505 vitiligo cases and 2253 controls from five case-control studies concentrating on the association between TNF-α-308 G/A polymorphism and vitiligo were included in this meta-analysis.
Since the presence of A nucleotide at position -308 of TNF-alpha gene is associated with increased cytokine production, therefore, the higher frequency of TNF-alpha -308 A allele in vitiligo patients compared to controls may be considered as a genetic susceptibility factor towards the development of vitiligo.
These findings indicate that the C allele of rs35652124 located in the promoter region of Nrf2 gene is associated with protective effect on vitiligo in a Han Chinese population.
C478T, one of the MC1R SNPs studied in 108 fair-skinned vitiligo patients and in 70 fair-skinned healthy control individuals, showed a significant difference (P=0.0262, odds ratio [95% confidence interval]=3.6 [0.0046-0.1003]) in allele frequency between the two groups: the allele frequency was higher in the control group, suggesting protection against vitiligo.
Recent investigations suggest an association between MC1R genotype and vitiligo, with preliminary evidence that a MC1R agonist, [Nle4-D-Phe7]-alpha-MSH, in combination with UVB, assists repigmentation.
For example, while the NOD-like receptor family, pyrin domain containing 1 (NLRP1) haplotypes contributes to susceptibility to developing vitiligo; there are other single nucleotide polymorphisms (SNPs) that alters the susceptibility and severity of rheumatoid arthritis (RA) and juvenile idiopathic arthritis.