Vitamin D receptor gene polymorphisms and the risk of multiple sclerosis: An updated meta-analysis

Vitamin D receptor gene polymorphisms in patients with relapsing multiple sclerosis

The relationship between the Vitamin D Receptor (VDR) gene and many pathogenic pathways in Relapsing-Remitting Multiple Sclerosis (RRMS) remains unclear. Given the significance of the topic, we conducted this study to explore the correlation between vitamin D receptor gene polymorphisms and clinical and inflammatory factors in patients suffering from relapsing-remitting multiple sclerosis. The current research is a case/control study conducted based on the Helsinki Ethical Principles. RRMS disease was confirmed based on history, clinical symptoms, radiological signs and neurologist diagnosis. The research population consisted of healthy people and patients with RRMS who were referred to Hazrat Rasool Akram Hospital between 2021 and 2023. For each person participating in the study (RRMS patient and healthy), five milliliters of peripheral blood containing the anticoagulant EDTA was collected. Polymerase chain reaction was performed using two specific and appropriate oligonucleotide primers. The restriction fragment length polymorphism technique was used, one of the standard methods for identifying polymorphisms. Statistical analysis was performed using SPSS software version 23. The odds ratio and 95% confidence limits were calculated. The SNP Analyzer software was used to analyze the allele frequency of each polymorphism in healthy and RRMS individuals and compare the values. Prism version 5 software was used to draw diagrams. In the present study, a statistically significant difference was observed between the percentage of FokI genotypes in RRMS patients and healthy individuals. FokI polymorphism showed a significantly increased risk with an odds ratio of 7.28 in patients with the FF genotype compared to healthy individuals. ApaI, TaqI, and BsmI were not significantly different between the two groups. Based on the findings of the present study, FokI polymorphism showed a significant risk increase in RRMS patients with FF genotype compared to healthy individuals.

Vitamin D in Multiple Sclerosis: A Comprehensive Umbrella Review

BACKGROUND

Multiple sclerosis (MS) is an inflammatory neuroimmune disease with a multifaceted etiology and long-lasting adverse effects. Several studies have explored the role of 25-hydroxyvitamin D (25(OH)D) serum levels, vitamin D receptor (VDR) gene polymorphisms, and vitamin D supplementation (VDS) in individuals with MS.

OBJECTIVES

The aim of this study was to evaluate the relationship of MS with 25(OH)D serum levels, VDR gene polymorphisms, and VDS.

METHODS

We assessed relevant articles published in PubMed, Scopus, and Web of Science from the inception up to 24 February, 2024. Meta-analyses that investigated the link of 25(OH)D serum levels, VDR gene polymorphisms including Apal (rs7975232), BsmI (rs1544410), Taql (rs731236), and Fokl (rs10735810), and VDS with the risk and clinical manifestations of MS were included. The methodological quality of selected articles was assessed by the Assessment of Multiple Systematic Reviews version 2. The statistical analysis of this umbrella review was carried out using RStudio version 2023.03.1 and R version 4.3.2, simultaneously.

RESULTS

A total of 23 of 304 records were entered into this umbrella review with a pooled sample size of 37,567 participants. Eleven articles were rated as high quality, 1 was moderate quality, 1 was low quality, and 10 were critically low quality. The homozygote model of FokI (FF+ff compared with Ff) was significantly associated with an 8% reduction of MS risk (odds ratio: 0.92, 95% confidence interval: 0.86, 0.98; I2 = 0%, P > 0.99).

CONCLUSION

According to existing clinical evidence, the risk of MS may be associated with VDR gene polymorphism. Further studies are needed to explore the association of MS and vitamin D.

TRIAL REGISTRATION NUMBER

This trial was registered at International Prospective Register of Systematic Reviews (PROSPERO) as registration number CRD42024521541.

Vitamin D Receptor Gene Polymorphism Predicts the Outcome of Multidisciplinary Rehabilitation in Multiple Sclerosis Patients

Better knowledge about the possible role of genetic factors in modulating the response to multiple sclerosis (MS) treatment, including rehabilitation, known to promote neural plasticity, could improve the standard of care for this disease. Vitamin D receptor (VDR) gene polymorphisms are associated with MS risk, probably because of the role played by vitamin D in regulating inflammatory and reparative processes. The aim of this study was to evaluate the association of the most important functional VDR SNPs (TaqI (T/C), ApaI (A/C), and FokI (C/T)) with functional outcome in MS patients undergoing multidisciplinary inpatient rehabilitation (MDR) treatment, in order to determine whether genetic profiling might be useful to identify subjects with a higher chance of recovery. To this end, 249 MS inpatients with a diagnosis of either progressive (pMS; n = 155) or relapsing remitting (RRMS; n = 94) disease who underwent MDR treatment (average duration = 5.1 weeks) were genotyped for VDR SNPs by real-time allelic discrimination. The rehabilitation outcome was assessed using the modified Barthel Index (mBI), Expanded Disability Status Scale (EDSS), and pain numerical rating scores (NRS) at the beginning and the end of MDR treatment. A positive correlation was observed in RRMS patients between the VDR TaqI major allele (TT) and mBI increase (i.e., better functional recovery), as assessed by the linear and logistic regression analysis adjusted for gender, age, disease duration, time of hospitalization, HLA-DRB1*15.01 positivity, and number of rehabilitative interventions (Beta = 6.35; p = 0.0002). The VDR-1 TaqI, ApaI, FokI: TCC haplotype was also associated with mBI increase in RRMS patients (Beta = 3.24; p = 0.007), whereas the VDR-2: CAC haplotype was correlated with a lower mBI increase (Beta = -2.18 p = 0.04) compared with the other haplotypes. VDR TaqI major allele (TT), as well as the VDR-1 TaqI, ApaI, FokI: TCC haplotype could be associated with a better rehabilitation outcome in RRMS patients.

Nuclear hormone receptors in demyelinating diseases

Demyelination results from the pathological loss of myelin and is a hallmark of many neurodegenerative diseases. Despite the prevalence of demyelinating diseases, there are no disease modifying therapies that prevent the loss of myelin or promote remyelination. This review aims to summarize studies in the field that highlight the importance of nuclear hormone receptors in the promotion and maintenance of myelination and the relevance of nuclear hormone receptors as potential therapeutic targets for demyelinating diseases. These nuclear hormone receptors include the estrogen receptor, progesterone receptor, androgen receptor, vitamin D receptor, thyroid hormone receptor, peroxisome proliferator-activated receptor, liver X receptor, and retinoid X receptor. Pre-clinical studies in well-established animal models of demyelination have shown a prominent role of these nuclear hormone receptors in myelination through their promotion of oligodendrocyte maturation and development. The activation of the nuclear hormone receptors by their ligands also promotes the synthesis of myelin proteins and lipids in mouse models of demyelination. There are limited clinical studies that focus on how the activation of these nuclear hormone receptors could alleviate demyelination in patients with diseases such as multiple sclerosis (MS). However, the completed clinical trials have reported improved clinical outcome in MS patients treated with the ligands of some of these nuclear hormone receptors. Together, the positive results from both clinical and pre-clinical studies point to nuclear hormone receptors as promising therapeutic targets to counter demyelination.

ε2 , ε3 , and ε4 variants of ApoE; rs2228570 (VDR), rs4588 and rs7041 (VDBP) polymorphisms in patients with multiple sclerosis: A case-control study in Turkish population

AIM OF THE STUDY

Multiple sclerosis (MS) is a degenerative disease characterized by autoimmune demyelination in the central nervous system. Yet, underlined genetics or environmental markers are still controversial. The impact of vitamin D and cholesterol on disease activity has been phrased by many studies; however, the data available for the Turkish population are very limited. This study aimed to investigate the effect of vitamin D-related polymorphisms (VDBP and VDR) and cholesterol-related variants of ApoE on Turkish MS patients.

MATERIALS AND METHODS

Total DNAs were extracted from peripheral blood samples of 51 MS patients and 50 healthy volunteers. rs4588 and rs7041 polymorphisms of VDBP, rs2228570 of VDR, as well as ε2, ε3, and ε4 variants of ApoE, were investigated by RT-PCR. Biochemical parameters which thought to be associated with MS were also measured. Results were evaluated statistically.

RESULTS

Homozygous mutant genotype and G allele of rs2228570 in VDR, as well as heterozygous genotype of rs4588 in VDBP, were found statistically high in patients. Total cholesterol, triglyceride, and LDL-C levels were found significantly high, whereas HDL-C and vitamin D levels were low in patients. An association was found between rs4588 variation and high triglyceride levels. Similar correlations were found between ε2 genotype and low LDL-C level; ε3 genotype and higher LDL-C. Gender, triglyceride, HDL-C, and AA genotype in rs4588 had a significant effect on MS progression.

CONCLUSION

The variations of rs2228570 and rs4588, vitamin D deficiency, and biological parameters related to cholesterol metabolism may be associated with MS risk.

Familial History of Autoimmune Disorders Among Patients With Pediatric Multiple Sclerosis

BACKGROUND AND OBJECTIVE

The objective of this study was to determine whether family members of patients with pediatric multiple sclerosis (MS) have an increased prevalence of autoimmune conditions compared with controls.

METHODS

Data collected during a pediatric MS case-control study of risk factors included information about various autoimmune diseases in family members. The frequency of these disorders was compared between cases and controls.

RESULTS

There was an increased rate of autoimmune diseases among family members of pediatric MS cases compared with controls with first-degree history of MS excluded (OR = 2.27, 95% CI 1.71-3.01, p < 0.001). There was an increased rate of MS among second-degree relatives of pediatric MS cases compared with controls (OR = 3.47, 95% CI 1.36-8.86, p = 0.009). The OR for MS was 2.64 when restricted to maternal relatives and 6.37 when restricted to paternal relatives.

DISCUSSION

The increased rates of autoimmune disorders, including thyroid disorders and MS among families of patients with pediatric MS, suggest shared genetic factors among families with children diagnosed with pediatric MS.

Association between polymorphisms in the vitamin D receptor and susceptibility to multiple sclerosis

OBJECTIVES

Multiple sclerosis (MS) is a neurodegenerative chronic inflammatory. Mutations in the vitamin D receptor (VDR) gene can substantially affect serum vitamin D levels or alter its functionality, and can consequently increase susceptibility to developing MS. The objective of this study was to evaluate the association between polymorphisms in the VDR gene and risk of MS in a (Spanish) Caucasian population.

PATIENTS AND METHODS

We conducted a retrospective case-control study comprising 209 patients with relapsing-remitting multiple sclerosis (RRMS) and 836 controls of Caucasian origin from southern Spain. The ApaI (rs7975232), BsmI (rs1544410), Cdx2 (rs11568820), FokI (rs2228570), and TaqI (rs731236) gene polymorphisms were determined by allelic discrimination real-time PCR using TaqMan probes.

RESULTS

The recessive logical regression model, adjusted for age and sex, revealed that the TT genotype for VDR FokI (rs2228570) polymorphism was associated with higher risk of MS (P = 0.0150; OR = 1.82; 95% CI = 1.12-2.94; TT vs. CT + CC). No association between the other polymorphisms and development of MS was found in any of the models analyzed. The haplotype analysis, adjusted for age, smoking, and sex, did not find any statistically significant association between the haplotypes analyzed and risk of MS.

CONCLUSIONS

The VDR FokI (rs2228570) polymorphism was significantly associated with developing MS. We found no influence of the ApaI (rs7975232), BsmI (rs1544410), Cdx2 (rs11568820), FokI (rs2228570), and TaqI (rs731236) gene polymorphisms on the risk of developing MS in our patients.

Association of Vitamin D Metabolism Gene Polymorphisms with Autoimmunity: Evidence in Population Genetic Studies

A high prevalence of vitamin D (calcidiol) serum deficiency has been described in several autoimmune diseases, including multiple sclerosis (MS), rheumatoid arthritis (AR), and systemic lupus erythematosus (SLE). Vitamin D is a potent immunonutrient that through its main metabolite calcitriol, regulates the immunomodulation of macrophages, dendritic cells, T and B lymphocytes, which express the vitamin D receptor (VDR), and they produce and respond to calcitriol. Genetic association studies have shown that up to 65% of vitamin D serum variance may be explained due to genetic background. The 90% of genetic variability takes place in the form of single nucleotide polymorphisms (SNPs), and SNPs in genes related to vitamin D metabolism have been linked to influence the calcidiol serum levels, such as in the vitamin D binding protein (VDBP; rs2282679 GC), 25-hydroxylase (rs10751657 CYP2R1), 1α-hydroxylase (rs10877012, CYP27B1) and the vitamin D receptor (FokI (rs2228570), BsmI (rs1544410), ApaI (rs7975232), and TaqI (rs731236) VDR). Therefore, the aim of this comprehensive literature review was to discuss the current findings of functional SNPs in GC, CYP2R1, CYP27B1, and VDR associated to genetic risk, and the most common clinical features of MS, RA, and SLE.

Vitamin D receptor genetic polymorphisms and the risk of multiple sclerosis: A systematic review and meta-analysis

There are conflicting results regarding the exact effect of the vitamin D receptor (VDR) gene polymorphisms on the susceptibility to multiple sclerosis (MS). Therefore, we aimed to investigate the impact of four major studied VDR gene polymorphisms consisting of ApaI, BsmI, FokI, and TaqI on the risk of MS in the Iranian population. A literature search was performed in various databases to find case-control studies evaluating the association between VDR gene polymorphisms and MS risk in Iran. Data were extracted and odds ratios (OR) with 95% confidence intervals (CI) were calculated. Subgroup analyze was performed to detect potential sources of heterogeneity. A total of 1206 cases and 1402 controls in nine case-control studies were included. ApaI was the only variant which showed statistically significant relation in allelic (OR = 0.54 (95% CI: 0.37-0.79); P = 0.00), homozygote (OR = 3.48 (95% CI: 1.7-6.9); P = 0.00), dominant (OR = 0.56 (95% CI: 0.3-0.79); P = 0.01), and recessive (OR = 0.35 (95% CI: 0.18-0.66); P = 0.00) models. The TaqI polymorphism showed a significant negative association with MS only in the homozygote model (OR = 0.28 (95% CI: 0.08-0.9); P = 0.04). The BsmI polymorphism also showed significant relation in allelic (OR = 0.69 (95% CI: 0.51-0.94); P = 0.01), homozygote (OR = 0.46 (95% CI: 0.25-0.86); P = 0.01), and recessive OR = 0.56 (95% CI: 0.39-0.8); P = 0.00) models after performing sensitivity analysis. FokI polymorphism showed no significant association with MS risk. ApaI and TaqI TT genotype were found contributing to MS susceptibility and BsmI and FokI showed no relation with MS susceptibility in the Iranian population.

Vitamin D receptor gene polymorphisms in multiple sclerosis disease: A case-control study

Multiple sclerosis (MS) is a common neurologic disorder that is a chronic inflammatory, demyelinating, and neurodegenerative disease of the central nervous system (CNS). Its etiology remains unknown. Several recent studies have found that decreased susceptibility to vitamin D deficiency is also associated with a decreased risk of MS. The role of vitamin D receptor (VDR) gene and its polymorphisms are highlighted as susceptible components. In this study, we aimed to identify the relationship between ApaI (rs7975232), BsmI (rs 1544410), and TaqI (rs731236) gene polymorphisms with MS. ApaI, BsmI, and TaqI genotypes were determined in 70 patients with MS and in 70 control subjects. DNA was isolated from blood samples, and then ApaI, BsmI and TaqI gene polymorphisms were identified using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. The distribution of BsmI and TaqI polymorphisms did not show any significant differences in MS patients and controls; however, increased A allele of ApaI polymorphism was found in MS patients. Our findings suggest that the ApaI gene polymorphism might be associated with MS. Investigation of a larger population and functional work on these gene structures and function in MS patients are recommended.

The association between vitamin D receptor polymorphisms and multiple sclerosis in a Turkish population

BACKGROUND

Multiple sclerosis (MS) is a chronic, demyelinating disease of the central nervous system (CNS). Genetic and environmental factors are important in disease development. Many studies have investigated the relationship between MS and VDR polymorphisms. VDR gene polymorphism has not been previously studied in Turkish MS patients. We aimed to investigate the relationship between MS and VDR genotypes Taq I, Apa I and Fok I polymorphisms in a Turkish population.

METHODS

167 MS patients and 146 healthy control subjects were included in the present study. MS and the VDR TaqI (rs731236), ApaI (rs7975232), and FokI (rs2228570) polymorphisms were investigated.

RESULTS

The study enrolled 167 patients (121 females, 46 males) with MS and 146 healthy individuals (88 females, 58 males). The frequency of only the Fok I polymorphism differed significantly between the two groups (p = 0.002). The TaqI (rs731236) and ApaI (rs7975232) genotype distributions were not significantly different between MS patients and healthy controls (p = 0.626 and p = 0.990, respectively). Also there were no significant gender difference between patients and controls for Taq I and Apa I.

CONCLUSION

In conclusion, we found a significant association between MS and the FokI polymorphism in our region of Turkey. However, the results may be different in other populations. More epidemiological and genetic studies are needed to explain the association between genetic factors and MS.