Association of genetic variants of the vitamin D receptor gene with vitiligo in a tertiary care center in a Saudi population: a case-control study

Association between miR-202, miR-211, and miR-1238 gene polymorphisms and risk of vitiligo

Vitiligo, as a common pigment defect in the skin, hair, and mucous membranes, results from the destruction of melanocytes. Recent investigations have shown that miRNA dysregulation contributes in the pathogenesis of vitiligo. Therefore, in this research, our aim is to explore the relationship between miR-202 rs12355840, miR-211 rs8039189, and miR-1238 rs12973308 polymorphisms and susceptibility to vitiligo. A total number of 136 vitiligo patients and 129 healthy individuals as a control group were included in this research. The salting out approach was implemented to extraction genomic DNA. The genetic polymorphisms of miR-202 rs12355840, miR-211 rs8039189, and miR-1238 rs12973308 were determined using PCR-RFLP approach. The findings revealed that miR-202 rs12355840 polymorphism under codominant (CT and TT genotypes), dominant, recessive, overdominant, and also allelic models is correlated with increased risk of vitiligo. In addition, codominant, dominant, overdominant, as well as allelic models of miR-211 rs8039189 polymorphism decrease risk of vitiligo. No significant relationship was observed between the miR-1238 rs12973308 polymorphism and susceptibility to vitiligo. The miR-211 rs8039189 polymorphism may serve a protective effect on vitiligo development and miR-202 rs12355840 polymorphism may act as a risk factor for vitiligo susceptibility.

Genetic susceptibility of vitamin D receptor gene polymorphisms on autosomal recessive primary microcephaly patients in Pakistani population: a case-control and in-silico study

BACKGROUND

Autosomal recessive primary microcephaly (MCPH) is a rare genetic disorder that leads to reduced cerebral cortex caused by a mutation in corticogenesis. The expression of the Vitamin D receptor (VDR) gene is involved in the proliferation and differentiation of neural stem cells, and VDR polymorphisms have been associated with various neurological disorders. However, their relationship with MCPH has not been explored. This study aimed to investigate the association of VDR polymorphisms with MCPH due to its role in Wnt signaling pathway and its In-silico analysis.

METHODS

Blood samples of 64 MCPH patients and 52 controls were collected to genotype VDR SNPs (TaqI (rs731236), FokI (rs2228570) and BsmI (rs1544410). In-silico tools were also used to assess the effects of exonic SNPs on mRNA and protein structure and pathogenicity of exonic and intronic SNPs.

RESULTS

The study found that serum 25-OH vitamin D3 levels were significantly different in MCPH patients and healthy controls (P = 0.000). The genetic analysis showed that VDR polymorphisms of FokI and BsmI were seven times more frequent in MCPH patients than in controls (P < 0.05) and the recessive model for TaqI and dominant model for BsmI polymorphisms were also associated with the pathogenesis of MCPH. In-silico analysis showed that the pathogenicity effects of rs2228570 and rs1544410 are neutral while rs731236 causes a silent mutation which has no effect on VDR protein.

CONCLUSION

VDR polymorphisms of FokI and BsmI are associated with the risk of MCPH. These findings suggest that VDR polymorphisms play a role in MCPH, which could provide important insights for understanding the molecular mechanisms of the disease.

Evaluation of CAT Variants A-89T, C389T, and C419T in Patients with Vitiligo in the Saudi Population

Background and Objectives: Vitiligo is a chronic autoimmune and depigmentation disorder in humans that manifests as whitening lesions. Reactive oxygen species (ROS) are involved in cell damage. Catalase (CAT) is a well-known oxidative stress regulator and is primarily responsible for the catalytic decomposition of hydrogen peroxide into water and oxygen. Based on previous case-control and meta-analysis studies, we assessed the prevalence of three single-nucleotide polymorphisms (SNPs) of the CAT genes A-89T (rs7943316), C389T (rs769217) and C419T (rs11032709) in participants with vitiligo and healthy controls in the Saudi population. Materials and Methods: We recruited 152 participants with vitiligo and 159 healthy controls for A-89T, C389T, and C419T SNP genotyping studies using PCR and RFLP analysis. Additionally, we performed linkage disequilibrium and haplotype analyses between vitiligo cases and controls. Results: The rs7943316 and rs11032709 SNPs of the CAT genes showed a positive association with vitiligo for both heterozygous genotypes and dominant genetic models (TT + AT vs. AA in A-89T and TT + CT vs. CC in C389T), in the CAT gene. Linkage disequilibrium analysis revealed a moderate linkage between rs7943316 and rs11032709 SNPs in vitiligo cases and controls. Haplotype frequency estimation revealed a significant association (p = 0.003) among the three SNP alleles. Conclusions: The rs7943316 and rs11032709 SNPs of the CAT genes were strongly associated with susceptibility to vitiligo.

Association between vitamin D receptor polymorphisms and vitiligo susceptibility: An updated meta-analysis

BACKGROUND

Vitamin D receptor (VDR) polymorphisms may play an important role in the vitiligo susceptibility. There have been many studies looking at the associations between VDR polymorphisms and vitiligo risk, but the conclusions are still up for debate.

AIM

This study aimed to determine whether polymorphisms in the VDR are associated to the susceptibility to vitiligo.

METHODS

Vitamin D receptor polymorphisms in vitiligo patients and controls were identified using PubMed/Medline and Embase databases. The relationships between the VDR ApaI, TaqI, BsmI, and TaqI polymorphisms and vitiligo were investigated using meta-analyses of all participants and Asian, Arab, European, and Latin American groups.

RESULTS

This meta-analysis included 13 papers with 2034 patients and 2771 controls. In all individuals, there was no link between vitiligo and the VDR ApaI A allele (OR = 0.889, 95% CI = 0.713-1.109, p = 0.298). However, in Asians (OR = 0.721, 95% CI = 0.553-0.940, p = 0.016) but not in Europeans or Arabs, there was a link between the VDR ApaI A allele and vitiligo. Utilizing recessive, dominant, and homozygote contrast models, a link between vitiligo and the VDR ApaI polymorphism was discovered in Asians. Meta-analysis of the VDR BsmI polymorphism showed a significant association between vitiligo and the B allele (OR = 0.812, 95% CI = 0.686-0.961, p = 0.015). In contrast, no connection between vitiligo and VDR polymorphisms was identified for TaqI and FokI polymorphisms.

CONCLUSION

In the Asian population, ApaI and BsmI polymorphisms in VDR have been correlated to vitiligo susceptibility. However, TaqI and FokI polymorphisms in VDR are not associated with vitiligo susceptibility in European, Asian, Arab, and Latin American populations.

A comprehensive meta-analysis and prioritization study to identify vitiligo associated coding and non-coding SNV candidates using web-based bioinformatics tools

Vitiligo is a prevalent depigmentation disorder affecting around 1% of the general population. So far, various Genome Wide Association Studies (GWAS) and Candidate Gene Association Studies (CGAS) have identified several single nucleotide variants (SNVs) as a risk factor for vitiligo. Nonetheless, little has been discerned regarding their direct functional significance to the disease pathogenesis. In this study, we did extensive data mining and downstream analysis using several experimentally validated datasets like GTEx Portal and web tools like rSNPBase, RegulomeDB, HaploReg and STRING to prioritize 13 SNVs from a set of 291SNVs that have been previously reported to be associated with vitiligo. We also prioritized their underlying/target genes and tried annotating their functional contribution to vitiligo pathogenesis. Our analysis revealed genes like FGFR10P, SUOX, CDK5RAP1 and RERE that have never been implicated in vitiligo previously to have strong potentials to contribute to the disease pathogenesis. The study is the first of its kind to prioritize and functionally annotate vitiligo-associated GWAS and CGAS SNVs and their underlying/target genes, based on functional data available in the public domain database.

Gene polymorphisms and serum levels of BDNF and CRH in vitiligo patients

Background

Vitiligo is one of the most common hypomelanoses, in which the destruction of functioning melanocytes causes depigmentation of the skin, hair and mucous membranes. The genes encrypting brain-derived neurotrophic factor (BDNF) and corticotropin releasing hormone (CRH) might be the conceivable contributors to the development of vitiligo. This study was aimed at investigation of the serum levels of BDNF and CRH as well as their selected single nucleotide polymorphisms (SNPs) in vitiligo patients in comparison with the healthy controls.

Methods

The cross-sectional study was carried out between October 2020 and June 2021 in 93 vitiligo patients (age range from 23 to 48 years) and 132 healthy controls (age range from 24 to 52 years). The psychological status of study participants was evaluated using the Generalized Anxiety Disorder-7 (GAD-7) scale. Serum levels of BDNF and CRH were measured with the help of a commercially available sandwich enzyme-linked immunosorbent assay (ELISA) kit. Genotyping for the rs11030094 polymorphism of the BDNF gene and for the rs242924 polymorphism of the corticotropin releasing hormone receptor 1 (CRH-R1) gene was performed by a real-time polymerase chain reaction (PCR).

Results

There was a significant relationship between the CRH-R1 rs242924 and BDNF rs11030094 polymorphisms and vitiligo. Moreover, serum levels of neurotransmitters differed significantly between vitiligo and control groups and were associated with the CRH-R1 rs242924 and BDNF rs11030094 SNPs.

Conclusions

Our findings demonstrated the association between CRH-R1 rs242924 and BDNF rs11030094 polymorphisms and vitiligo. Further studies need to be carried out in vitiligo patients to confirm the results observed.