Vitamin D receptor gene polymorphisms in relation to Vitamin D related disease states

Association of VDR Polymorphisms (FokI, ApaI, and TaqI) with Susceptibility to Lumbar Disc Herniation: Systematic Review, Meta-Analysis, Trial Sequential Analysis, and Transcriptional Prediction

Background and Objectives: Lumbar disc herniation (LDH) is influenced by genetic, mechanical, and behavioral factors, with genetic predisposition playing a key role. Vitamin D receptor (VDR) polymorphisms have been implicated in LDH susceptibility, warranting further investigation. This study aimed to assess the association between VDR polymorphisms (FokI, ApaI, and TaqI) and LDH risk through a systematic review, meta-analysis, and trial sequential analysis (TSA). Materials and Methods: A systematic literature search was conducted across PubMed, Web of Science, Scopus, Cochrane Library, and CNKI, up until 30 January 2025. A meta-analysis was performed using Review Manager 5.3, with odds ratios (ORs) and 95% confidence intervals (CIs), and heterogeneity assessed via the I2 statistic. The publication bias and TSA were evaluated using CMA 3.0 and TSA software to ensure the reliability of the results. The FATHMM-XF method was applied to predict the functional effect of coding and non-coding polymorphisms. Results: From 79 records, 10 studies were entered into the meta-analysis. The meta-analysis results showed no significant association of FokI and ApaI polymorphisms with LDH, while TaqI exhibited a protective effect, particularly in Asian populations and larger studies. The subgroup analysis revealed significant ethnicity-specific associations for TaqI, with stronger effects observed in Asian compared to Caucasian individuals. The trial sequential analysis indicated that additional studies are required to confirm the findings for FokI, while the recessive model of TaqI polymorphism showed a near-sufficient sample size for reliable conclusions. Conclusions: The TaqI polymorphism, particularly the tt genotype, appears to have a protective effect against LDH, especially in Asian populations and larger studies. However, further large-scale, multi-ethnic research is needed to confirm these findings and explore underlying biological mechanisms.

Downstream Link of Vitamin D Pathway with Inflammation Irrespective of Plasma 25OHD3: Hints from Vitamin D-Binding Protein (DBP) and Receptor (VDR) Gene Polymorphisms

Background: Vitamin D insufficiency/deficiency is a highly prevalent condition worldwide. At the same time, chronic inflammation is a versatile pathophysiological feature and a common correlate of various disorders, including vitamin D deficiency. Methods: We investigated the possible association of inflammation with 25-hydroxyvitamin D3 (25OHD3) levels and its down-stream pathway by exploring vitamin D-binding protein (DBP) and vitamin D receptor (VDR) genes for single-nucleotide polymorphisms (SNPs), in healthy non-elderly Bahraini adults. Plasma levels of 25OHD3 were measured by chemiluminescence, and six SNPs, four in the GC gene (rs2282679AC, rs4588CA, rs7041GT, and rs2298849TC) and two in the VDR gene (rs731236TC and rs12721377AG) were genotyped by real-time PCR. The concentrations of five inflammatory biomarkers, IL6, IL8, procalcitonin (PCT), TREM1, and uPAR, were measured by ELISA. Results: The results showed no association between the 25OHD3 level and any of the inflammatory markers' levels. However, three tested SNPs were significantly associated with the concentrations of tested biomarkers except for IL6. The TT mutant genotype of rs2298849TC was associated with lower levels of IL8 and higher levels of PCT and TREM1, the AA mutant genotype of rs2282679AC was associated with decreased levels of IL8 (p ≤ 0.001) and increased levels of TREM1 (p = 0.005), and the GG wild genotype of rs12721377AG was associated with increased levels of 25OHD3 (p = 0.026). Conclusions: Although chronic inflammation is not associated with the vitamin D system in the blood, it is downstream, as revealed by DBP and VDR genotyping. Alternatively, DBP and VDR pursue other functions beyond the vitamin D pathway.

Association Between Vitamin D Receptor BsmI Polymorphism and Low Bone Mineral Density in Postmenopausal Women in the MENA Region

BACKGROUND/OBJECTIVES

Low bone mineral density increases the risk of bone fractures, and this condition is especially common in postmenopausal women. Genetic factors significantly influence bone mineral density. This meta-analysis examined the relationship between vitamin D receptor (VDR) gene polymorphisms (BsmI, ApaI, and TaqI) and bone mineral density in postmenopausal women in the Middle East and North Africa (MENA) region.

METHODS

The PubMed, Embase, Scopus, and Web of Science databases were searched from inception to March 2024 for case-control studies on VDR BsmI, ApaI, and TaqI polymorphisms and their relationship with low bone density. Associations with low bone mineral density were tested with respect to different genetic models (dominant, recessive, allelic) using RevMan v5.3.

RESULTS

The meta-analysis included seven studies for BsmI, six for ApaI, and seven for TaqI, representing 704/689 cases/controls for BsmI, 914/711 for ApaI, and 974/895 for TaqI. No significant association was found between VDR polymorphisms and low bone mineral density in postmenopausal women, except in the dominant model (CC + CG vs. GG) for the BsmI variant (OR = 1.27, 95% CI: 1.01-1.59, p = 0.04).

CONCLUSIONS

We found a modest association between the BsmI polymorphism and increased risk of low bone mineral density (BMD) in postmenopausal women from the MENA region, suggesting its potential as a biomarker. No associations were observed for ApaI or TaqI. These findings highlight the complex genetic-environmental interactions influencing BMD.

Genomic Insights into Host Susceptibility to Periprosthetic Joint Infections: A Comprehensive Literature Review

Periprosthetic joint infection (PJI) is a multifactorial disease, and the risk of contracting infection is determined by the complex interplays between environmental and host-related factors. While research has shown that certain individuals may have a genetic predisposition for PJI, the existing literature is scarce, and the heterogeneity in the assessed genes limits its clinical applicability. Our review on genetic susceptibility for PJI has the following two objectives: (1) Explore the potential risk of developing PJI based on specific genetic polymorphisms or allelic variations; and (2) Characterize the regulatory cascades involved in the risk of developing PJI. This review focused on clinical studies investigating the association between genetic mutations or variations with the development of PJI. The genes investigated in these studies included toll-like receptors and humoral pattern recognition molecules, cytokines, chemokines, mannose-binding lectin (MBL), bone metabolism molecules, and human leukocyte antigen. Among these genes, polymorphisms in IL-1, MBL, vitamin D receptors, HLA-C, and HLA-DQ might have a relevant impact on the development of PJI. The literature surrounding this topic is limited, but emerging transcriptomic and genome-wide association studies hold promise for identifying at-risk genes. This advancement could pave the way for incorporating genetic testing into preoperative risk stratification, enhancing personalized patient care.

Association of vitamin D receptor genetic polymorphisms with the risk of infertility: a systematic review and meta-analysis

BACKGROUND

The causes of infertility have remained an important challenge. The relationship between VDR gene polymorphisms and infertility has been reported, with controversial findings.

OBJECTIVE AND RATIONALE

We aimed to determine this relationship by conducting a systematic review and meta-analysis.

SEARCH METHODS

The study was started with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) declaration and the final draft was registered as a protocol in PROSPERO (ID: CRD42023416535). The international electronic databases including PubMed (Medline), Scopus, Web of Sciences, and Cumulative Index to Nursing and Allied Health Literature (CINHAL) were searched until January 30, 2023, by using appropriate keywords. The quality of the final studies was assessed using the NOS Checklist for case-control studies. The odds ratios (ORs) for each of the genetic models were pooled, and a subgroup analysis based on geographical region and types of infertility was carried out by the MetaGenyo online tool.

OUTCOMES

Case-control studies including 18 and 2 studies about infertility in women and men, respectively, and 4 miscarriage studies were entered into the meta-analysis. The VDR gene TaqI polymorphism was associated with infertility susceptibility in women in the allele contrast [OR = 1.2065, 95% CI (1.0846-1.3421); P = 0.0005], Recessive model [OR = 1.3836, 95% CI (1.1197-1.7096); P = 0.002], Dominant model [OR = 1.2146, 95% CI (0.0484-1.4072); P = 0.009], Homozygote [OR = 1.4596, 95% CI (1.1627-1.8325); P = 0.001], and TT vs. Tt [OR = 1.2853, 95% CI (1.0249-1.6117); P = 0.029. ApaI and FokI gene polymorphisms were found to be significantly protective SNPs against women and men infertility in the Dominant model [OR = 0.8379, 95% CI (0.7039- 0.9975); P = 0.046] and Recessive model [OR = 0.421, 95% CI (0.1821-0.9767); P = 0.043], respectively. Sub-group meta-analysis showed a protection association of ApaI in dominant [OR = 0.7738, 95% CI = 0.6249-0.9580; P = 0.018] and AA vs. aa [OR = 0.7404, 95 CI% (0.5860-0.9353) P = 0.011725] models in PCOS subgroup, however, a negative association with idiopathic infertility was found in AA vs. Aa [OR = 1.7063, 95% CI (1.1039-2.6375); P = 0.016187] and Aa vs. aa [OR = 0.6069, 95% CI (0.3761-0.9792); P = 0.040754]. TaqI SNP was significantly associated with infertility in the African population and BsmI was associated with the disease mostly in the Asian population.

CONCLUSION

This meta-analysis showed that the TaqI polymorphism may be linked to women's infertility susceptibility. However, ApaI and FokI might be the protective SNPs against infertility in Women and men, respectively.

Vitamin D supplementation can enhance therapeutic effects of excimer laser in patients with vitiligo

PURPOSE

Vitiligo is a disease of acquired depigmentation characterized by the destruction of melanocytes. A theoretical association between low level of 25-hydroxyvitamin D [25(OH)D] and vitiligo has been previously suggested. The objective of this study was to determine the efficacy of intramuscular injection of cholecalciferol with excimer laser compared with the excimer laser alone for vitiligo treatment.

METHODS

This study included 26 patients diagnosed with non-segmental vitiligo and low serum 25(OH)D levels (<20 ng/mL). The participants were randomly divided into two groups through randomization. The treatment using a 308-nm excimer laser was administered to both groups, and the study group additionally received cholecalciferol injection.

RESULTS

The Vitiligo Area Scoring Index (VASI) scores showed an 83.6% improvement over the initial score in the study group, whereas the control group showed a 54.7% improvement after 6 months of treatment. After 6 months of treatment, the study group showed a significantly higher proportion of patients who achieved VASI50 and VASI75 compared with the control group.

CONCLUSION

Intramuscular injection of cholecalciferol can be a supplemental option for the treatment of vitiligo patients with vitamin D deficiency with excimer laser therapy.

Frequency of Healthy Control Genotype of VDR Gene Polymorphisms in the Saudi Population of the Ha'il Region: A Comparative Study with Worldwide Population

Genetic polymorphisms in the vitamin D receptor (VDR) may influence the biological effects of vitamin D and increase a person's susceptibility to cancer. Previous studies have shown that different ethnic groups exhibit varying frequencies of the VDR gene variants TaqI, ApaI, FokI, and BsmI. However, the allelic distribution of these VDR polymorphisms in the Saudi population of Ha'il region is not sufficiently explored. In this study, efforts were made to ascertain the frequency of VDR polymorphisms in the Saudi population of Ha'il region, and then comparison was made for VDR polymorphism rates with other populations of the world. Allele and genotype frequencies of VDR TaqI, ApaI, BsmI and FokI gene was determined. The frequency distribution for the variant allele of VDR TaqI, ApaI, BsmI and FokI was found to be 70, 33, 50 and 25%, respectively. A significant frequency distribution was found for VDR-TaqI, ApaI and FokI variants in comparison with other populations of the world. Whereas, almost all of the studies dealing with VDR-FokI failed to show substantial difference while comparing with the data reported from the population of Ha'il region of Saudi Arabia. A significant pattern in the frequency of VDR gene variations have been found in the Saudi population of Ha'il region, which may be attributed to ethnic variance. The understanding of the worldwide distribution of VDR markers could help with high-risk screening of those who are exposed to environmental hazards and people of Ha'il region, who are predispose to cancer.

Association of vitamin D deficiency and vitamin D receptor (VDR) gene single-nucleotide polymorphism (rs7975232) with risk of preeclampsia

BACKGROUND

Preeclampsia has a multifactorial-yet-elusive etiology. Recent reports suggest a link between preeclampsia and vitamin D (VD) metabolic axis. Genetic variations like single-nucleotide polymorphisms (SNPs) of vitamin D receptor (VDR) gene can alter the metabolic role of VD, which have been shown by several genetic association studies. However, there is discordance among these studies.

OBJECTIVE

The current study aimed to investigate the association of VDR gene polymorphism (ApaI) and VD deficiency with risk of developing preeclampsia.

PATIENTS AND METHOD

In this case-control study, 40 preeclamptic and 40 normotensive pregnant women were compared for VD status and VDR gene polymorphism. Serum 25-hydroxyvitamin-D [25(OH) D] level was determined by enzyme-linked immunosorbent assay (ELISA) and VDR gene polymorphism Apa1 was analyzed by Allele specific polymerase chain reaction (AS-PCR) using sequence specific primers.

RESULTS

Serum levels of 25(OH) D were very low but comparable in both preeclamptic and normotensive pregnant women. The difference between the two groups were not statistically significant (p = .423). VDR gene polymorphism ApaI (rs7975232) was found not to have significant association with the risk of developing preeclampsia. The frequencies of wild genotype (GG) in preeclamptic and normotensive women were 27.5% and 22.5% respectively. A total of 25% of preeclamptic women had mutant homozygous genotype (TT) and 17.5% of normotensive women had mutant homozygous genotype. The frequency of mutant heterozygous genotype (GT) in preeclamptic patients was 47.5% and in normotensive women was 60%. The variation of wild and mutant genotypes between the two groups was not statistically significant (p > .05).

CONCLUSION

This study showed that VDR gene polymorphism (ApaI) and VD deficiency are not associated with the risk of preeclampsia.

Impact of vitamin D binding protein (GC) and vitamin D receptor (VDR) gene polymorphism on the risk of developing preeclampsia

OBJECTIVE

Preeclampsia is a multifactorial disease characterized by high blood pressure and protein in the urine. In this study, we investigated the association of vitamin D binding protein (GC) and vitamin D receptor (VDR) gene polymorphism with the risk of developing preeclampsia.

METHODS

25-hydroxyvitamin D was measured using High-performance Liquid Chromatography. Vitamin D binding protein and vitamin D receptor gene polymorphisms were determined by polymerase chain reaction-restriction fragment length polymorphism.

RESULTS

The control subjects have significant higher level of 25-hydroxyvitamin D (33.5 ± 1.194 ng/mL) relative to patients (23.97 ± 1.604 ng/mL) (p < 0.05). Vitamin D receptor rs1544410 and rs2228570 dominant model (GA + AA; TC + CC) showed significant higher risk of developing Preeclampsia (OR = 4.11, 95% CI = 0.62-27.09, p < 0.01; OR = 3.58, 95%CI = 0.78-16.38, p < 0.001 respectively). Similarly, vitamin D binding protein rs7041 and rs4588, dominant model (TG + GG; CA + AA) showed higher risk of preeclampsia development compared to control people (OR = 1.69, 95%CI = 0.35-8.19, p < 0.05; OR = 1.06, 95%CI = 0.25-4.44, p < 0.05 respectively). AA genotype of rs4588 of GC gene was significantly associated with 25-hydroxyvitamin D level in serum relative to CC and CA (p < 0.05).

CONCLUSION

From our study, we can conclude that a low level of 25-hydroxyvitamin D, GC (rs1544410 and rs2228570), and VDR (rs4588 and rs7041) gene polymorphism is linked with an increased risk of developing preeclampsia.

Vitamin D receptor gene polymorphism and polycystic ovary syndrome susceptibility

BACKGROUND

Polycystic ovary syndrome (PCOS) is the most common endocrinopathy in women. This study was designed to investigate the associations of vitamin D receptor (VDR) gene variants with PCOS risk and the severity of the disease phenotype among Egyptian women.

METHODS

In this study, 185 women with PCOS and 207 fertile women as controls were recruited. Cases were divided into phenotype groups based on their clinical and paraclinical features. Clinical and laboratory data were measured in the patient and control groups. All individuals were genotyped for nine single-nucleotide polymorphisms (SNPs) located across the VDR gene using Taq^Man allelic discrimination real-time polymerase chain reaction.

RESULTS

Women with PCOS were significantly (P ≤ 0.001) higher body mass index (BMI) (22.77 ± 2.5) than controls (21.68 ± 1.85 kg/m²). Women with PCOS had significantly higher anti-Mullerian hormone, prolactin, luteinizing hormone (LH), LH/follicle-stimulating hormone (FSH), free testosterone, total testosterone, and dehydroepiandrosterone sulfate levels than the control group (P ≤ 0.001). The level of FSH was significantly lower in women with PCOS than in the control group (P ≤ 0.001). Analysis of the VDR rs4516035, rs2107301, rs1544410 (BsmI), and rs731236 (TaqI) SNPs showed a significant association with PCOS phenotype A. Furthermore, rs2228570 (FokI), rs3782905, rs7975232 (ApaI), and rs739837 SNPs showed a significant association with PCOS phenotype C. Furthermore, rs11568820 SNP showed a significant association with PCOS phenotype D (P < 0.05).

CONCLUSIONS

The findings of this study indicate that variations in the VDR gene were associated with an increased risk of PCOS in Egyptian women.

Association of vitamin D levels and polymorphisms in vitamin D receptor with type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is a leading cause of death. The prevalence of T2DM in countries of the Middle East and North Africa (MENA) region, including Jordan, is among the highest worldwide. The reason(s) behind the epidemic nature of T2DM in Jordan are unknown but warrant further exploration. Studies have indicated that T2DM could be influenced by diet and/or genetic background. Evidence suggests that numerous patients with T2DM are deficient in vitamin D. The activity of vitamin D on its target tissues may be influenced by single nucleotide polymorphisms (SNPs) in the vitamin D receptor (VDR) gene. It was therefore hypothesized that SNPs in VDR could modify the risk of T2DM. To test this hypothesis, 125 patients with T2DM were recruited along with 125 controls. The study subjects were genotyped for variations in rs2228570, rs1544410, rs7975232, and rs731236 SNPs in the VDR. The levels of 25-hydroxyvitamin D [25(OH)D] were measured from the serum. The analysis revealed that reduced 25(OH)D and age were associated with the risk of T2DM (P<0.05). Moreover, under a dominant inheritance model, the GG genotype of rs2228570 was revealed to increase the risk of T2DM in univariate and multivariate analysis (P<0.05). Additionally, a chromosomal block containing the GAAG haplotype of VDR SNPs increased the risk of T2DM (OR=1.909; CI: 1.260-2.891; P=0.0021). Collectively, the present study revealed that low levels of serum 25(OH)D and rs2228570 of the VDR gene are associated with the risk of T2DM.

The interactive effect of vitamin D3 supplementation and vitamin D receptor polymorphisms on weight and body composition in overweight women with hypovitaminosis D: a randomized, double-blind, placebo-controlled clinical trial

Different responses to vitamin D supplementation may be due to genes involved in vitamin D metabolism, including the vitamin D receptor (VDR) gene. The present study aimed to determine the interactive effect of vitamin D supplementation and VDR polymorphisms, including FokI (rs2228570) and BsmI (1544410) on weight and body composition in overweight women with hypovitaminosis D. This study comprised two phases: a double-blind, randomized and a before-after clinical trial. In the first phase, 50 healthy overweight women aged 20-45 years with hypovitaminosis D were randomly categorized into intervention and control groups and were given 50 000 IU/w vitamin D3 or placebo for 12 weeks. In the second phase, 75 women received 50 000 IU/w of vitamin D3 for 12 weeks. All variables were measured at baseline and after 12 weeks. Circulating 25(OH)D was measured using an ELISA kit. Anthropometric indices were calculated according to standard protocol (WHO-TRH-854). Body composition was determined using the body impedance analysis method. The VDR polymorphisms were detected using the PCR sequence. Supplementation resulted in a significant increase in the level of 25(OH)D in the intervention group but did not affect the anthropometric profile of the subjects. When considering FokI genotypes, carriers of the FF genotype had higher fat mass reduction than carriers of Ff + ff genotypes.

5Apal, Taql, Fokl, and Bsml polymorphisms and the susceptibility of Behcet's disease: an updated meta-analysis

OBJECTIVE

The aim of this study was to investigate whether the gene polymorphisms of vitamin D receptor (VDR) had a genetic effect on the susceptibility of Behcet's disease (BD).

MATERIAL AND METHODS

We conducted a meta-analysis emphasizing the association between the VDR gene polymorphisms and the risk of BD. The strength of the association in five genetic models was assessed by pooled odds ratios (OR) with a corresponding 95%confidence interval (CI).

RESULTS

A total of seven independent comparisons with 478 cases and 666 healthy controls were included in this meta-analysis. The overall results suggested that a significant association between ApaI polymorphism and BD risk was found in allele comparison, recessive model, and homozygote model among total populations. Subgroup analysis indicated that a significant association of ApaI polymorphism in the development of BD existed under the allelic model among Africans, while for Caucasians, a similar link was identified in the recessive model and homozygote model. Regarding Bsml polymorphism, an obvious relationship was detected to be significant in allele comparison and recessive model in the Caucasian population. Interestingly, the Fokl variant decreased the risk of BD in Africans under five genetic models, while it increased the risk in Caucasians across the recessive model and homozygote model.

CONCLUSION

The results of this meta-analysis provide evidence of the link between the four widely studied polymorphisms in the VDR gene and BD, indicating a robust estimate of the genetic risk.

Gene polymorphisms in asthma: a narrative review

Background and Objective

Asthma is a heterogeneous disease caused by interactions between genetic and environmental factors. Genome-wide association studies (GWAS) have revealed that genetic variation plays a crucial role in the occurrence and development of asthma. The objective is to systematically review the existing literature on the association between gene polymorphisms and asthma to better understand the relationship between genetic factors and the occurrence and development of asthma.

Methods

We used keywords "asthma" and "gene polymorphism" with their combinations to search for relevant literature published from 2000 to 2021 in the PubMed database and the foreign medical literature retrieval service (FMRS). All articles included in the review are English. Then, we summarized the information pertaining to the genetic factors related to asthma susceptibility.

Key Content and Findings

This study summarized the information on 10 gene variants related to the risk of asthma published over the past 20 years, which will assist in further understanding the role of genetic variants in the risk of asthma.

Conclusion

Dozens of candidate genes have been identified that were associated with asthma risk. Asthmatics existed specific gene variation performed different response to therapy. Personalized therapy based on genotypic profiling would be an important direction in the future. However, it remains a great challenge for us to explore the relationship between gene polymorphisms and pathophysiological mechanism of asthma.

Osteoporosis and its Association with Vitamin D Receptor, Oestrogen α Receptor, Parathyroid Receptor and Collagen Type I alpha Receptor Gene Polymorphisms with Bone Mineral Density: A Pilot Study from South Indian Postmenopausal Women of Tamil Nadu

The involvement of many putative genetic factors makes osteoporosis a complex disease. With increasing longevity of the Indian population, it's now being realized that, as within the West, osteoporotic fractures are also a significant explanation for morbidity and mortality in postmenopausal women. Studies have suggested that the genetic component liable for bone mass could be linked to single nucleotide polymorphisms. Therefore, this study is aimed to research the role of seven gene polymorphisms previously associated with bone phenotype in a cohort of postmenopausal South Indian women from Tamil Nadu. The subjects for the study (n = 300) included 100 osteoporotic women (age 59.3 ± 9.26), 100 osteopenic women (age 55.6 ± 8.17) and 100 non-osteoporotic women as controls (age 55.4 ± 8.85).Genetic polymorphisms were determined by polymerase chain reaction (PCR)-restriction fragment length polymorphism. Case-control genetic association analysis of BsmI of the VDR and BstBI of the PTH gene showed a significant allelic association with low bone mineral density amongst the osteoporotic postmenopausal women. The association of BMD with the VDR gene polymorphisms revealed that the average BMD in the BsmI polymorphism with the recessive genotype GG in osteoporotic women was significantly reduced compared with the average BMD in osteoporotic women with AA and AG genotypes. In the BstBI polymorphism, the BMD in the osteoporotic subjects were significantly lower in the AA group than in the GA and GG groups. These results provide evidence for an independent association between BMD and rs1544410 in VDR and rs6254 in PTH and may contribute in being a possible genetic marker for predicting the disease susceptibility in the population tested.

Vitamin D deficiency is a risk factor for delayed tooth eruption associated with persistent primary tooth

OBJECTIVE

To verify the association between 25(OH)D level and polymorphisms in the vitamin D receptor gene (VDR) with the disturbance in the dental development and eruption.

DESIGN

A total of 183 children from two datasets were evaluated. The first dataset was a case-control (15:15) designed to assess if persistent primary tooth (PPT) is associate with serum 25(OH)D level and with genetic polymorphisms in VDR. The second dataset of genomic DNA samples from 54 children with delayed tooth eruption (DTE) and 99 controls were analysed to verify if genetic polymorphisms in VDR (rs2228570 and rs739837) are associated with DTE. The 25(OH)D and the genotyping/allele distribution were analysed using the T-test and chi-square test, respectively.

RESULTS

The level of 25(OH)D in the PPT group (24.9 ± 6.4 mg/mL) was significantly lower than the control (30.0 ± 7.0 mg/mL) (p=.047). Our data show that children with 25(OH)D deficiency are more likely to present PPT (OR = 2.36; 95%CI: 1.51, 3.70). The rs739837 and rs2228570 polymorphisms were not associated with DTE (OR = 1.44; 95%CI: 0.87, 2.39 and OR = 0.80; 95%CI: 0.45, 1.44, respectively).

CONCLUSIONS

Vitamin D deficiency is a risk factor for PPT.

The Most Common Vitamin D Receptor Polymorphisms (ApaI,FokI, TaqI, BsmI, and BglI) in Children with Dental Caries: A Systematic Review and Meta-Analysis

Vitamin D participates in the calcification of enamel and dentin and the appropriate immune responses to oral microbial infections. We aimed to assess the association between the most common vitamin D receptor (VDR) polymorphisms (ApaI,FokI, TaqI, BsmI, and BglI) and the risk of dental caries in children.

METHODS

PubMed/MEDLINE, Cochrane Library, Web of Science, and Scopus databases were comprehensively searched until 19 January 2021. Meta-analysis with odds ratios as the effect estimate along with 95% confidence intervals and subgroup analysis were conducted using Review Manager 5.3 software. Publication bias and sensitivity analyses were conducted by Comprehensive Meta-Analysis, version 2.0 software.

RESULTS

Seventy-eight studies were retrieved from the databases, with nine studies included in the final analysis. Based on five genetic models, there was no association between ApaI (rs7975232), TaqI (rs731236), BsmI (rs1544410), FokI (rs2228570), and BglI (rs739837) polymorphisms and susceptibility to dental caries, except for the FokI (rs10735810) polymorphism.

CONCLUSION

Among the VDR polymorphisms considered, an association was found between the FokI (rs10735810) polymorphism and the risk of dental caries, with a protective role of the f allele and ff genotype.

Vitamin D and VDR Gene Polymorphisms' Association with Rheumatoid Arthritis in Lithuanian Population

Background and Objectives: Rheumatoid arthritis (RA) is a chronic, inflammatory, autoimmune, multi-factorial disease, in which environmental and genetic factors play a major role. RA is possibly linked to vitamin D deficiency and vitamin D receptor (VDR) gene polymorphisms, and research demonstrates that FokI variant susceptibility is associated with increased disease risk among Caucasians. The aim of this study was to evaluate vitamin D deficiency prevalence and its correlation to RA clinical parameters, and to determine the possible association of VDR gene polymorphisms and RA susceptibility in the Lithuanian population. Materials and Methods: Overall, 206 RA patients and 180 age- and sex-matched healthy controls were enrolled at Vilnius University Hospital Santaros Klinikos after informed consent was obtained. The disease activity score 28 C-reactive protein (DAS28 CRP), rheumatoid arthritis impact of disease (RAID) score, and health assessment questionnaire (HAQ) were recorded in RA patients, and 25(OH)D serum levels were evaluated by chemiluminescent microparticle immunoassay for all subjects. Four VDR gene polymorphisms, BsmI, FokI, ApaI, and TaqI, were assessed using real-time PCR instruments and genotyping assays in both groups. Results: The study registered a high prevalence of 25(OH)D deficiency (<50 nmol/L) in RA patients (61.55% (n = 127)). The mean serum concentration in RA patients (44.96 ± 21.92 (nmol/L)) was significantly lower than in the healthy controls (54.90 ± 22.82 (nmol/L)), p < 0.0001. A significant inverse correlation between vitamin D level, DAS28 CRP, and HAQ scores was confirmed in RA patients, with p < 0.05. Still, there was no significant association between the overall risk of RA disease for any allele or genotype of the four VDR loci tested. Conclusions: The study confirmed that vitamin D deficiency is prevalent among RA patients and the 25(OH)D level is significantly lower compared with healthy controls. Lower vitamin D concentration was related with increased disease activity and disability scores. However, genetic analysis of four VDR polymorphisms did not confer the susceptibility to RA in Lithuanian population.

Association of serum levels and receptor genes BsmI, TaqI and FokI polymorphisms of vitamin D with the severity of multiple sclerosis

PURPOSE

Multiple sclerosis (MS) is a chronic inflammatory and neurodegenerative disease. Vitamin D has a major role in preventing inflammatory disorders. Therefore, any alteration in vitamin D receptor (VDR) might be a genetic risk factor for MS development. This study aimed to evaluate the effect of serum levels and VDR FokI, BsmI, and TaqI gene polymorphisms on the severity of MS.

METHODS

This case-control study recruited 160 MS patients (71.9% females, mean age of 34.3 ± 8.3 years) and 162 (66.7% females, mean age 35.4 ± 7.9 year) age, sex, and ethnicity matched healthy controls. FokI (rs2228570), BsmI (rs1544410), and TaqI (rs731236) polymorphisms were carried out using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Demographic, clinical parameters, and the levels of vitamin D were compared between groups.

RESULTS

We found that the frequency of FokI and TaqI polymorphisms significantly differed between the patients and the controls (p = 0.0127 and p = 0.0236, respectively). The MS patients had low levels of vitamin D compared to the controls (p = 0.011). In addition, TaqI T/C polymorphism significantly decreased the levels of vitamin D in the MS patients (p = 0.002). However, there was no significant association between FokI or BsmI SNPs and the levels of vitamin D in MS patients (p > 0.5).

CONCLUSION

Our results suggest that FokI and TaqI polymorphisms of VDR are associated with MS risk and TaqI polymorphism is associated with Vitamin D levels in MS patients. Meanwhile, no difference was observed between VDR gene polymorphisms and any types of MS.

Relationship between serum 25-hydroxyvitamin D, total antioxidant capacity and pneumonia incidence, severity and outcome in Nigerian children

Background

The pathologic basis of childhood community-acquired pneumonia (CAP) involves the generation of reactive oxygen species by immune cells leading to cellular damage and lung congestion. Serum antioxidants and vitamin D with immunomodulatory properties therefore hold prospects in the prevention and management of pneumonia in children. This case–control study set out to compare the serum 25-hydroxyvitamin D (25-OHD) and total antioxidant capacity (TAC) in Nigerian children with CAP and age- and sex-matched controls and to relate these parameters with pneumonia severity and outcome—length of hospital stay (LOH).

Results

A total of 160 children (80 each for CAP and controls) were recruited. The median (IQR) age was 1.8 (0.6–4.0) years, male:female 1.7:1, 63 (78.8%) and 11 (13.8%) of CAP group had severe pneumonia and parapneumonic effusions, respectively. Serum 25-OHD (33.8 (18.3) ng/ml vs. 41.9 (12.3) ng/ml; p = 0.010) and TAC (6.1 (4.4–8.1) ng/dl vs. 7.2 (4.7–17.5) ng/dl; p = 0.023) were lower in children with CAP than controls. Lower serum 25-OHD was observed in severe than non-severe pneumonia (30.5(17.1) ng/ml vs. 46.3 (17.6) ng/ml; p = 0.001) but LOH did not correlate with serum 25-OHD and TAC.

Conclusion

Children with CAP had lower serum vitamin D and antioxidants than controls, and severe pneumonia was significantly associated with suboptimal serum vitamin D. They however were not related to pneumonia outcome. Optimal serum vitamin D and antioxidants may play a role in reducing the incidence of childhood CAP in Nigerian children.

Association of BsmI variant of vitamin D receptor gene with polycystic ovary syndrome: A case-control study

Background

Polycystic ovarian syndrome (PCOS) is an endocrine disorder that affects women's fertility and causes alterations such as obesity, insulin resistance, menstrual irregularities, and polycystic ovaries. The results of the studies show that the issue of vitamin D and vitamin D receptor (VDR) is controversial for PCOS susceptibility.

Objective

To investigate the association of BsmI polymorphism in the VDR gene with metabolic parameters in obese PCOS women.

Materials and Methods

In this case-control study, 38 obese subjects with PCOS and 40 unrelated obese individuals were evaluated to determine the allelic and genotypic frequency of BsmI variant by Polymerase Chain Reaction Restriction Fragment Length Polymorphism method. Body Mass Index, parathyroid hormone, phosphorus, and calcium were evaluated in all participants.

Results

BsmI (rs1544410), (A/G) AA, AG, GG, A, and G percentage of genotypic/allelic frequencies were 65.8, 26.3, 7.9, 78.9, and 21.1 in cases and 57.5, 40, 2.5, 77.5, and 22.5 in controls, respectively. Statistical analysis revealed that the differences in genotypic (p = 0.31)/allelic (p = 0.83) frequencies and dominant (p = 0.45)/recessive (p = 0.35) models between the cases and controls were not significant. This study indicates no association between the BsmI genotypes and metabolic parameters.

Conclusion

It can be concluded that VDR BsmI (rs1544410) Intron 8 (A > G) was not associated with obesity along with PCOS susceptibility in the studied groups.

The relationships of vitamin D, vitamin D receptor gene polymorphisms, and vitamin D supplementation with Parkinson's disease

In recent years, many studies have investigated the correlations between Parkinson's disease (PD) and vitamin D status, but the conclusion remains elusive. The present review focuses on the associations between PD and serum vitamin D levels by reviewing studies on the associations of PD with serum vitamin D levels and vitamin D receptor (VDR) gene polymorphisms from PubMed, Web of Science, Cochrane Library, and Embase databases. We found that PD patients have lower vitamin D levels than healthy controls and that the vitamin D concentrations are negatively correlated with PD risk and severity. Furthermore, higher vitamin D concentrations are linked to better cognitive function and mood in PD patients. Findings on the relationship between VDR gene polymorphisms and the risk of PD are inconsistent, but the FokI (C/T) polymorphism is significantly linked with PD. The occurrence of FokI (C/T) gene polymorphism may influence the risk, severity, and cognitive ability of PD patients, while also possibly influencing the effect of Vitamin D3 supplementation in PD patients. In view of the neuroprotective effects of vitamin D and the close association between vitamin D and dopaminergic neurotransmission, interventional prospective studies on vitamin D supplementation in PD patients should be conducted in the future.

The Role of Vitamin D Receptor Gene Polymorphisms in Colorectal Cancer Risk

Vitamin D deficiency has been associated with increased colorectal cancer (CRC) incidence risk and mortality. Vitamin D mediates its action through the binding of the vitamin D receptor (VDR), and polymorphisms of the VDR might explain these inverse associations. The aim of the study was the investigation of the relevance of rs731236; Thermus aquaticus I (TaqI), rs7975232; Acetobacter pasteurianus sub. pasteurianus I (ApaI), rs2228570; Flavobacterium okeanokoites I (FokI) and rs1544410, Bacillus stearothermophilus I (BsmI) polymorphisms of the VDR gene to colorectal carcinogenesis (CRC) and progression. Peripheral blood was obtained from 397 patients with early operable stage II/III (n = 202) and stage IV (n = 195) CRC. Moreover, samples from 100 healthy donors and 40 patients with adenomatous polyps were also included as control groups. Genotyping in the samples from patients and controls was performed using polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP). A significant association was revealed between all four polymorphisms and cancer. Individuals with homozygous mutant (tt, aa, ff or bb) genotypes were more susceptible to the disease (p < 0.001). All of the mutant genotypes detected were also significantly associated with stage IV (p < 0.001), leading to significantly decreased survival (p < 0.001). Moreover, all four polymorphisms were significantly associated with KRAS (Kirsten ras oncogene) mutations and Toll-like receptor (TLR2, TLR4 and TLR9) genetic variants. In multivariate analysis, tt, aa and ff genotypes emerged as independent factors associated with decreased overall survival (OS) (p = 0.001, p < 0.001 and p = 0.001, respectively). The detection of higher frequencies of the VDR polymorphisms in CRC patients highlights the role of these polymorphisms in cancer development and progression.

Vitamin D receptor (VDR) gene polymorphism and risk of rheumatoid arthritis (RA): systematic review and meta-analysis

Vitamin D is involved in immune system modulation as well as in calcium and bone homeostasis, hence plays a role in rheumatoid arthritis (RA) etiopathogenesis. A bulk of studies in different populations have assessed the association between the vitamin D receptor (VDR) gene polymorphisms and the risk of RA, reporting conflicting results. Therefore, we designed a meta-analysis to comprehensively evaluate the association of VDR gene polymorphisms and RA risk. All potential studies reporting the association between VDR gene polymorphisms and susceptibility to RA published till February 2020 were retrieved through systematic search of database, including Scopus and MEDLINE. Strength of pooled association was determined through calculating the pooled odds ratios (ORs) and 95% confidence intervals (CIs). Subgroup analysis was performed by stratifying the studies by population type. This meta-analysis included 23 eligible studies (21 articles) overall. We noticed that FokI SNP had a significant protective association with susceptibility to RA in the overall analysis as well as in Europeans and Asians. TaqI SNP decreased the RA risk in Africans and Arabs, but not in the overall analysis. Likewise, BsmI SNP and RA risk in the overall population analysis was not significant. Interestingly, BsmI polymorphism increased RA risk in Africans. This meta-analysis offers a significant association between VDR gene polymorphism and susceptibility to RA in both overall and ethnic-specific analysis. However, different polymorphisms acted inversely in increasing or decreasing RA risk in different populations.

Could Vitamin D influence risk for Periodontal Disease - to "D" or not to "D"?

PURPOSE OF REVIEW

The purpose of this review is to discuss the literature on associations between vitamin D and periodontal disease, including its strengths and weaknesses. Future direction for continued work in this area is provided.

RECENT FINDINGS

Research in cross-sectional cohorts, surveys, and case-control studies provide support for a role of vitamin D in periodontal disease, especially using clinical indicators such as bleeding on probing and clinical attachment loss. However, these studies have a number of limitations. They cannot establish temporality of these associations. Most case-control studies have been limited in sample size and have inconsistent findings. A number of cross-sectional studies are restricted to select populations (e.g., persons with HIV, diabetes, rheumatoid arthritis) limiting extrapolation of findings to the general aging population.Fewer prospective studies have been conducted, and only three have examined associations using a biomarker for vitamin D that reflects exposure from all its sources (sunlight, diet and supplements). One study is limited by using self-reported measures of disease outcomes, and only two used measures of alveolar crestal height. However, of the prospective studies published, there is a suggestion that vitamin D might prevent against tooth loss. Only two randomized controlled trials have examined these associations, and they support the effects of vitamin D supplementation on prevention of tooth loss and gingival bleeding.

SUMMARY

We strongly suggest that new research should focus on prospective study designs with followup of participants longer than a decade and long-term clinical trials. Such studies should incorporate measures of alveolar bone loss and tooth loss with indication for reason for tooth loss. Such clinical trials should be designed to examine both the influence of vitamin D supplementation alone as well as with other nutrients (e.g., calcium) or therapeutic medications (e.g., bisphosphonates). Currently, there is no strong evidence to suggest that vitamin D protects against development of periodontal disease.

Association of polymorphisms in the vitamin D receptor gene with susceptibility to and severity of hand, foot, and mouth disease caused by coxsackievirus A16

Coxsackievirus A16 (CA16) remains the most common causative agent of hand, foot, and mouth disease (HFMD), and is related to high incidence and critical complications. Vitamin D receptor (VDR) activity might affect the outcome of CA16 infection. Our case-control research aims to evaluate the relationship between VDR polymorphisms in the gene encoding and susceptibility to and severity of HFMD due to CA16. Three single-nucleotide polymorphisms (SNPs) of VDR gene were selected according to functional prediction and linkage disequilibrium, and were examined utilizing the SNPscan method to identify possible associations with HFMD caused by CA16. A significant relationship was found in the HFMD cases of polymorphism rs11574129 (GA vs GG: odds ratio (OR) = 0.068, 95% confidence interval (CI) = 0.007-0.693, P = .023; GA + AA vs GG: OR = 0.322, 95%CI = 0.106-0.984, P = .047), and vitamin D levels in genotype AA were significantly higher than those in genotype GG (P < .05). These results suggest that VDR rs11574129 may influence genetic susceptibility to CA16-associated HFMD.

Older Age Is Associated with Decreased Levels of VDR, CYP27B1, and CYP24A1 and Increased Levels of PTH in Human Parathyroid Glands

Parathyroid glands contain the vitamin D receptor (VDR) and 25-hydroxyvitamin D-1α-hydroxylase (CYP27B1) and 24-hydroxylase (CYP24A1), which catalyze the production and degradation of 1,25-dihydroxyvitamin D [1,25(OH)₂D], respectively. Previous studies have shown that the serum level of intact parathyroid hormone (iPTH) increases with age. We hypothesized that the expression of CYP27B1 or VDR in parathyroid glands decreases with age, which might account for the increased serum levels of iPTH due to decreased suppression of parathyroid hormone (PTH) secretion by 1,25(OH)₂D in older people. To test this hypothesis, we examined relative expression levels of VDR, CYP27B1, CYP24A1, and PTH in specimens from parathyroid glands unintentionally removed during thyroidectomy for 70 patients varying in age from 10 to 70 years. The results showed that there was an inverse correlation between age and VDR, CYP27B1, and CYP24A1 expression (p < 0.05). A significant positive correlation between PTH expression levels and age was also observed (p < 0.05). These data indicate that older age is associated with decreased levels of VDR, CYP27B1, and CYP24A1 and increased levels of PTH in human parathyroid glands.

Associations of Vitamin D Receptor Single Nucleotide Polymorphisms with Susceptibility to Systemic Sclerosis

BACKGROUND

This study aims to evaluate whether the Vitamin D receptor (VDR) gene polymorphisms were associated with systemic sclerosis (SSc) in a Chinese Han population.

METHODS

Using a hospital-based case-control study including 100 SSc patients and 100 healthy controls. Single nucleotide polymorphisms (SNPs) in the VDR region were genotyped by the improved multiplex ligase detection reaction (i MLDR) method. Haplotypes were also constructed after linkage disequilibrium (LD) analysis.

RESULTS

Eight SNPs (rs731236 (TaqI), rs2228570 (FokI), rs7975232 (ApaI), rs1544410 (BsmI), rs11574010 (Cdx2), rs739837 (BglI), rs757343 (Tru9I) and rs11168267) were included. There were significant differences between SSc patients and healthy individuals in ApaI and BglI genotype (both adjusted p = 0.008). Through the genotyping, significantly association of SSc were found for: dominant model of ApaI and BglI (both OR (95% CI) = 1.80 (1.03,3.16), p = 0.040). Furthermore, the elevation of erythrocyte sedimentation rate (ESR) had a higher percentage of BglI GT genotype frequency (p = 0.034) and dominant model of ApaI (p = 0.016) in SSc. There was high linkage disequilibrium was detected in BglI and ApaI polymorphisms (r² = 1.0, D' = 1.0), Tru9I and rs11168267 (r² = 0.926, D' = 0.969), respectively. No significant difference were found in these four haplotypes (all p >0.05). The correlation between VD levels and VDR gene polymorphisms was not statistically significant.

CONCLUSIONS

Our preliminary study indicates the ApaI and BglI genotype may possibly have a role in the pathogenesis of SSc patients. Dominant model of ApaI and BglI GT genotype frequency may be associated with the increased risk of ESR.

Ecogenetics of lead toxicity and its influence on risk assessment

Lead (Pb) toxicity is a public health problem affecting millions worldwide. Advances in 'omic' technology have paved the way to toxico-genomics which is currently revolutionizing the understanding of interindividual variations in susceptibility to Pb toxicity and its functional consequences to exposure. Our objective was to identify, comprehensively analyze, and curate all the potential genetic and epigenetic biomarkers studied to date in relation to Pb toxicity and its association with diseases. We screened a volume of research articles that focused on Pb toxicity and its association with genetic and epigenetic signatures in the perspective of occupational and environmental Pb exposure. Due to wide variations in population size, ethnicity, age-groups, and source of exposure in different studies, researchers continue to be skeptical on the topic of the influence of genetic variations in Pb toxicity. However, surface knowledge of the underlying genetic factors will aid in elucidating the mechanism of action of Pb. Moreover, in recent years, the application of epigenetics in Pb toxicity has become a promising area in toxicology to understand the influence of epigenetic mechanisms such as DNA methylation, chromatin remodeling, and small RNAs for the regulation of genes in response to Pb exposure during early life. Growing evidences of ecogenetic understanding (both genetic and epigenetic processes) in a dose-dependent manner may help uncover the mechanism of action of Pb and in the identification of susceptible groups. Such studies will further help in refining uncertainty factors and in addressing risk assessment of Pb poisoning.

Role of VDR, GC, and CYP2R1 Polymorphisms in the Development of Hepatocellular Carcinoma in Hepatitis C Virus-Infected Patients

Aims: This study was designed to determine if vitamin D receptor (VDR), carrier globulin/binding protein (GC), and cytochrome P-450 family 2, subfamily R, polypeptide 1 (CYP2R1) gene polymorphisms are risk factors in the development of hepatocellular carcinoma (HCC) in hepatitis C virus (HCV)-infected patients from Northeast India. Materials and Methods: A total of 351 HCV-infected patients were enrolled of which 167 were diagnosed with chronic hepatitis C (CHC), 124 with liver cirrhosis (LC), and 60 with HCC together with 102 age- and sex-matched healthy controls. VDR (BsmI, ApaI, and TaqI), GC (rs4588, rs7051), and CYP2R1 (rs10741657) gene polymorphisms were genotyped for all subjects. Statistical data were analyzed using SPSS ver. 22.0. Results: The frequency of the ApaI CC genotype, ApaI C allele, and bAt haplotype of the VDR gene was significantly higher in HCC and LC patients than controls. After adjusting for other covariates (age, gender, platelet count, AST, ALT, serum albumin, and viral load) logistic regression analysis showed that the ApaI CC genotype and bAt haplotype were independent predictors of HCC development. No significant associations was found for the GC and CYP2R1 polymorphisms examined with the occurrence of HCC. Conclusions: The presence of the VDR ApaI CC genotype and bAt haplotype appear to be important indicators in the development of HCC among HCV-infected patients. Larger studies are needed to further clarify and establish this potential causal relationship.

Association of polymorphisms in the vitamin D receptor gene with severity of hand, foot, and mouth disease caused by enterovirus 71

Severe hand, foot, and mouth disease (HFMD) is sometimes associated with critical complications that can cause substantial child mortality. Activity of the vitamin D receptor (VDR) may influence the outcomes of enterovirus 71 (EV71) infection. This case-control study aimed to assess the association of single-nucleotide polymorphisms (SNPs) in the gene encoding the VDR with the severity of EV71-associated HFMD. We selected four VDR SNPs based on linkage disequilibrium and functional prediction, and we tested them using the SNPscan multiple SNP typing method for potential association with severity of EV71-associated HFMD. We found a significant association in the case of rs11574129 (G vs A: odds ratio (OR), 0.3439; 95% confidence intervals (CI), 0.1778-0.6653) and rs739837 (T vs G: OR, 0.5580; 95%CI, 0.3352-0.9291). Our results suggest that these two SNPs may influence the severity of EV71-associated HFMD.

Association of vitamin D receptor gene polymorphisms with osteosarcoma risk and prognosis

OBJECTIVE

Through its receptor (VDR), vitamin D3 plays an important role in a wide variety of cellular processes. Polymorphisms in VDR gene have been linked to risk of various cancers and their prognoses. We conducted a case-control study to analyze he relationship of VDR gene polymorphisms with the occurrence and prognosis of osteosarcoma.

METHODS

Fifty-eight osteosarcoma patients and 75 healthy controls were included in the study. Single nucleotide change polymorphisms (SNPs) in Cdx2, FokI, BsmI, ApaI and TaqI regions of VDR gene were examined with SNaPshot mini-sequencing technique. Allele and genotype frequencies in patients and controls were compared. The association of polymorphic genotypes with osteosarcoma was evaluated. The relationship of the presence of polymorphism to prognostic parameters and survival rates were also analyzed.

RESULTS

Allele and genotype frequencies of Cdx2, FokI, BsmI, ApaI and TaqI regions in VDR gene were found to be similar in patients and controls. Polymorphisms in these regions were not associated with osteosarcoma risk. In patients having Cdx2 polymorphic allele, tumor volume was greater (p:0.041), metastasis was more common (p:0.042) and histopathological response to chemotherapy was worse (p:0.044). Good histopathological response was significantly higher in patients with BsmI homozygous polymorphism (p:0.037). In the presence of heterozygous Cdx2 and homozygous a higher three-year overall survival rate was found, while there was a higher event-free survival rate in patients with ApaI polymorphisms.

CONCLUSION

Our results suggested that although polymorphisms of VDR gene are not related to the development of osteosarcoma, they may be important for prognosis. Understanding the effect of VDR polymorphisms on osteosarcoma will be important in identifying new prognostic parameters and new targets for treatment.

Polymorphic Variations in VDR Gene in Saudi Women with and Without Polycystic Ovary Syndrome (PCOS) and Significant Influence of Seven Polymorphic Sites on Anthropometric and Hormonal Parameters

BACKGROUND

This study was designed to evaluate the associations between vitamin D receptor (VDR) gene polymorphisms and biochemical characteristics of Saudi women with polycystic ovary syndrome (PCOS).

METHODS

Serum levels of LH, FSH, and Vitamin D were measured in 33 women: 16 patients and 17 normal controls (18 to 36 years). DNA was extracted and used for sequencing of the exons of VDR gene using ABI PRISM 3730xi Genetic Analyzer.

RESULTS

Weight, BMI, Vit D, LH and FSH levels were higher in the PCOS patients compared to control group, where Vit D level correlated positively and significantly with FSH, in the control, but showed a negative and non-significant correlation in the PCOS patients. Sequencing results showed extensive polymorphisms in both groups, but the differences in the frequencies were not significant. Demographic and hormonal parameters were compared in the different genotypes of the SNPs. Significant differences were ob served in the values of the studied parameters in rs11168276, rs11168266, rs3858733, rs121909790, rs11168265 and rs731236. Vitamin D level was influenced significantly by the genotypes of rs11168265 (AA) (p=0.008), rs11168276 (AA; p=0.018) and rs731236 (CC; p=0.024).

CONCLUSION

Vitamin D deficiency does not associate with PCOS in Saudi females. Several SNPs are identified in the VDR gene, in normal and PCOS females, but there is no difference in their frequencies between the two groups. The results show that polymorphism in VDR gene influences certain anthropometric and hormonal parameters in PCOS patients. Further detailed studies are required to confirm the associations between VDR and PCOS.

Serum 25-hydroxyvitamin D, serum calcium and vitamin D receptor (VDR) polymorphisms in a selected population with lumbar disc herniation-A case control study

Background

Association of Vitamin D receptor (VDR) polymorphisms with lumbar disc herniation (LDH) have been identified in several ethnic groups globally. Despite abundant sunlight, vitamin D deficiency is reported in many tropical countries. As vitamin D is a key modulator for intestinal calcium absorption, low vitamin D could contribute to low serum calcium leading to abnormalities of skeletal homeostasis. Therefore, present study was aimed to study the association of serum 25-hydroxyvitamin D (25(OH)D), serum calcium and VDR polymorphisms in a selected Sri Lankan population.

Materials & methods

A case control study was conducted in 119 participants (cases = 51: controls = 68). Serum 25(OH)D levels were measured using ELISA. The VDR polymorphisms (Fok I and Taq I) were detected by polymerase chain reaction followed by restriction fragment length polymorphism.

Results

Findings indicated a significantly low (p = 0.000) 25(OH)D levels in cases (18.7±3.7 ng/mL) compared to controls(25.5±9.8 ng/mL) while 25(OH)D in both groups were below the reference range. Mean serum calcium levels in both groups were within normal reference range and was not significantly different among groups. Statistically significant association was not observed between VDR Fok I polymorphisms among cases and controls. Although Fok I polymorphism genotypes were in Hardy-Weinberg equilibrium (HWE), Taq I genotypes in controls violated HWE.

Conclusion

Present study confirms that insufficient serum 25(OH)D levels in cases have major contribution to LDH. VDR Fok I polymorphisms did not have any significant association with LDH in Sri Lankan ethnicity.

Vitamin D status and premature adrenarche

BACKGROUND

Vitamin D, an important factor in calcium-phosphate homeostasis, has recently been suggested to play an important role in the pathogenesis of numerous chronic conditions such as hyperandrogenism. The aim of this study was to investigate the relationship between vitamin D status and premature adrenarche (PA).

METHODS

A total of 71 girls with PA and 52 healthy girls, as the control group, were recruited. Axillary and/or pubic hair development before the age of 8 years was defined as PA. Bone age and anthropometric measures including height, weight, and body mass index (BMI) were obtained. 25-Hydroxyvitamin D (25(OH)D), fasting plasma glucose and insulin were measured. Vitamin D insufficiency was defined as <20 ng/mL.

RESULTS

The PA patients had older bone age, higher BMI standard deviation score, homeostasis model of assessment-insulin resistance (HOMA-IR), and androgen but lower 25(OH)D than the control group. HOMA-IR and dehydroepiandrosterone sulfate were also higher in PA patients with vitamin D insufficiency compared with those with normal vitamin D. There was a negative correlation between 25(OH)D and HOMA-IR.

CONCLUSION

Low vitamin D is associated with PA; and insulin resistance may be a factor in this association.

Single Nucleotide Polymorphisms in the Vitamin D Receptor Gene (VDR) May Have an Impact on Acute Pancreatitis (AP) Development: A Prospective Study in Populations of AP Patients and Alcohol-Abuse Controls

Vitamin D imbalance is suggested to be associated with the development of pancreatitis. Single nucleotide polymorphisms (SNPs), Apa-1, Bsm-1, Fok-1, and Taq-1, in the vitamin D receptor gene (VDR) are known in various diseases, but not yet in pancreatitis. The aim of this study was to explore possible associations of the four SNPs in the VDR receptor gene in a population of acute pancreatitis patients and alcohol-abuse controls, and to investigate the association with acute pancreatitis (AP) susceptibility. The study population (n = 239) included acute pancreatitis patients (n = 129) and an alcohol-abuse control group (n = 110). All patients met the Diagnostic and Statistical Manual of Mental Disorders (DSM IV) criteria for alcohol dependence. DNA was extracted from peripheral leukocytes and analyzed for VDR polymorphisms using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Odd ratios (ORs) and 95% confidence intervals (CIs) were calculated using logistic regression analysis. To date, we have found allele T in Taq-1 (OR = 2.61; 95% CI: 1.68⁻4.03; p < 0.0001) to be almost three times more frequent in the AP group compared to the alcohol-abuse control patients. Polymorphism Taq-1 occurring in the vitamin D receptor may have an impact on the development of acute pancreatitis due to the lack of the protective role of vitamin D.

Pseudoexfoliative glaucoma and molecular genetic characteristics of vitamin D metabolism

Purpose. To study the possible association of 25-hydroxyvitamin D level, and vitamin D receptor (VDR) gene polymorphisms (BsmI, ApaI, TaqI, FokI) with pseudoexfoliative glaucoma (PEG) clinical manifestations. Methods. We examined 160 subjects (72 males (45%), and 88 females (55%)) aged from 55 to 75 years, residents of St. Petersburg and Leningrad region. 122 patients with PEG were enrolled in the main study group, the control group comprised 38 subjects without PEG, primary open angle glaucoma (POUG) and pseudoexfoliation syndrome (PES). 25(OH)D serum levels were assessed by chemiluminescent immunoassay (CLIA) method. Detection of VDR gene allele polymorphisms (ApaI, BsmI, FokI, and TaqI) was carried out using polymerase chain reaction – restriction fragment length polymorphism (PCR-RFLP) technique. Results. Patients with PEG had lower 25(OH)D serum levels compared to patients in the control group (39.3 ± 1.2 and 52.7 ± 2.1 nMol/l, respectively, p < 0.01). The prevalence of vitamin D deficiency was found to be higher among PEG patients than among healthy subjects (86.4% and 59.5%, respectively, p < 0.01). The prevalence of b allele (p < 0.001) and bb genotype (p < 0.001) (BsmI polymorphism), as well as of f allele and ff genotype (p < 0.05) (FokI polymorphism) in PEG patients were higher compared to healthy subjects. We found that the Fallele carriers (FokI polymorphism) had greater corneal thickness than the ff genotype carriers (547.3 ± 4.1 μm and 502.1 ± 25.8 μm, respectively, p < 0.01). It was revealed, that bb genotype, Bb genotype (BsmI polymorphism), and ff genotype (FokI polymorphism) were associated with the increased risk of PEG (OR = 8.2, CI 95%: 3.4-19.9; OR = 3.9, CI 95%: 1.7-9.0; OR = 2.3, CI 95%: 1.2-4.5, respectively). Conclusions. Results of this study for the first time ever showed the association between BsmI and FokI VDR gene polymorphisms and pseudoexfoliative glaucoma.

On the role of classical and novel forms of vitamin D in melanoma progression and management

Melanoma represents a significant clinical problem affecting a large segment of the population with a relatively high incidence and mortality rate. Ultraviolet radiation (UVR) is an important etiological factor in malignant transformation of melanocytes and melanoma development. UVB, while being a full carcinogen in melanomagenesis, is also necessary for the cutaneous production of vitamin D3 (D3). Calcitriol (1,25(OH)2D3) and novel CYP11A1-derived hydroxyderivatives of D3 show anti-melanoma activities and protective properties against damage induced by UVB. The former activities include inhibitory effects on proliferation, plating efficiency and anchorage-independent growth of cultured human and rodent melanomas in vitro, as well as the in vivo inhibition of tumor growth by 20(OH)D3 after injection of human melanoma cells into immunodeficient mice. The literature indicates that low levels of 25(OH)D3 are associated with more advanced melanomas and reduced patient survivals, while single nucleotide polymorphisms of the vitamin D receptor or the D3 binding protein gene affect development or progression of melanoma, or disease outcome. An inverse correlation of VDR and CYP27B1 expression with melanoma progression has been found, with low or undetectable levels of these proteins being associated with poor disease outcomes. Unexpectedly, increased expression of CYP24A1 was associated with better melanoma prognosis. In addition, decreased expression of retinoic acid orphan receptors α and γ, which can also bind vitamin D3 hydroxyderivatives, showed positive association with melanoma progression and shorter disease-free and overall survival. Thus, inadequate levels of biologically active forms of D3 and disturbances in expression of the target receptors, or D3 activating or inactivating enzymes, can affect melanomagenesis and disease progression. We therefore propose that inclusion of vitamin D into melanoma management should be beneficial for patients, at least as an adjuvant approach. The presence of multiple hydroxyderivatives of D3 in skin that show anti-melanoma activity in experimental models and which may act on alternative receptors, will be a future consideration when planning which forms of vitamin D to use for melanoma therapy.

Vitamin D status, serum lipid concentrations, and vitamin D receptor (VDR) gene polymorphisms in Familial Mediterranean fever

Vitamin D (VitD) is critical for the regulation of inflammatory processes, and VitD deficiency has been linked to several chronic inflammatory disorders. We aimed to investigate the concentrations of serum 25(OH)D3, lipid parameters, and three known VDR polymorphisms (BsmI, FokI, and TaqI) in patients with Familial Mediterranean fever (FMF), an autosomal recessive autoinflammatory disease. The study included 123 FMF patients and 105 controls. Seventy patients had no attack (group 1), 30 had 1-2 attacks (group 2), and 23 had 3 or more attacks (group 3) within last three months. Serum 25(OH)D3 concentrations were determined using liquid chromatography-tandem mass spectrometry. BsmI, FokI, and TaqI polymorphisms were analyzed by a competitive allele specific polymerase chain reaction assay (KASPar). Serum lipid parameters were measured with enzymatic colorimetric methods. 25(OH)D3 concentrations were lower in FMF patients compared to controls (p < 0.001). No difference was observed in 25(OH)D3 concentration between groups 1, 2, and 3. The distributions of FokI and TaqI genotypes were not significantly different between FMF patients and controls. There was a significant difference in the distribution of AA BsmI genotype between male FMF patients and male controls. Increased concentrations of triglycerides (p = 0.012) and decreased concentrations of high-density lipoprotein cholesterol [HDL-C] (p = 0.006) were found in FMF patients compared to controls. Although lower 25(OH)D3 concentrations were observed in FMF patients versus controls, no association was determined between FMF attack frequency and 25(OH)D3 concentrations. We showed that the AA genotype of BsmI polymorphism is associated with FMF in males but not in females. The effects of decreased HDL-C and increased triglyceride concentrations on cardiovascular events in FMF patients should be further investigated.

Vitamin D receptor gene polymorphisms and risk of polycystic ovary syndrome in South Indian women

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder of reproductive age women. Emerging evidence suggests that Vitamin D Receptor (VDR) might be a causal factor for characteristics associated with PCOS such as obesity and type 2 diabetes. Present study investigated association between VDR gene BsmI A/G (rs1544410), ApaI A/C (rs7975232) and TaqI T/C (rs731236) single nucleotide polymorphisms and PCOS risk in South Indian women. Genotyping of VDR gene SNPs was carried out in PCOS patients (n = 95) and controls (n = 130) by PCR-RFLP method and confirmed by sequencing analysis. Haplotype frequencies for multiple loci and the standardized disequilibrium coefficient (D') for pairwise linkage disequilibrium (LD) were assessed by Haploview software. Results showed significantly increased frequencies of BsmI G/G (p = .0197), ApaI C/C (p = .048), TaqI C/C (p = .044) genotypes and BsmI G (p = .0181), ApaI C (p = .0092), TaqI C (p = .0066) alleles in patients compared to controls. In addition, the frequency of the 'BsmI G, ApaI C, TaqI C' haplotype was also significantly elevated in patients (p = .0087). In conclusion, the VDR gene BsmI A/G ApaI A/C TaqI T/C and haplotype may constitute an inheritable risk factor for PCOS in South Indian women.

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.

Vitamin D receptor gene polymorphisms among Emirati patients with type 2 diabetes mellitus

At a prevalence rate close to 19.5%, the UAE has one of the highest rates of Type 2 Diabetes Mellitus (T2DM) in the world. Genome wide association studies (GWAS) have led to the identification of several genetic variants that are associated with T2DM. Recently, genes involved in vitamin D metabolism have gained interest because of the association between vitamin D deficiency (VDD) and increased risk for T2DM. Among these, the Vitamin D receptor (VDR) gene is a good candidate for T2DM susceptibility. The aim of this study was to investigate the association between VDR polymorphisms and T2DM among a representative sample of the Emirati population. In this cross sectional study, two hundred and sixty four patients with T2DM and ninety-one healthy controls were enrolled. The study population was genotyped for the three VDR gene mutations, TaqI (rs731236), FokI (rs2228570) and BsmI (rs1544410). VDR alleles and haplotypes were compared between patients and their healthy controls. The mean age of the T2DM cohort was 60±11.59years and 48.21±12.17years for the healthy controls. The G-allele and GG genotype of rs2228570 and T-allele and TT genotype of rs1544410 SNPs were associated with T2DM. In regards to T2DM-related metabolic complications, the AG and GG genotypes of rs731236 were significantly associated with higher total cholesterol (p=0.011) and LDL-cholesterol (p=0.009) levels in the patients with T2DM. In contrast, the CT genotype of rs1544410 was significantly associated with lower BMI (p=0.031) and the TT genotype was associated with lower LDL-cholesterol level (p=0.007). The frequency of AAT and GGC haplotypes was also different between groups (p=0.014; p=0.032, respectively), implying that these haplotypes of the VDR gene are associated with the susceptibility to T2DM in the Emirati population. To conclude, an association between SNPs in the VDR gene (except for rs731236) and T2DM per se was demonstrated. The rs731236 variant was shown to be associated with high cholesterol and LDL-cholesterol levels in T2DM patients, while rs1544410 was associated with lower BMI and lower LDL cholesterol levels. Our results imply that alleles and haploypes of the VDR gene are associated with the susceptibility to T2DM in the Emirati population.

Association between Single Nucleotide Polymorphisms in Vitamin D Receptor Gene Polymorphisms and Permanent Tooth Caries Susceptibility to Permanent Tooth Caries in Chinese Adolescent

Purpose

Dental caries is a multifactorial infectious disease. In this study, we investigated whether single nucleotide polymorphisms (SNPs) in vitamin D receptor (VDR) gene were associated with susceptibility to permanent tooth caries in Chinese adolescents.

Method

A total of 200 dental caries patients and 200 healthy controls aged 12 years were genotyped for VDR gene polymorphisms using the PCR-restriction fragment length polymorphism (PCR-RFLP) assay. All of them were examined for their oral and dental status with the WHO criteria, and clinical information such as the Decayed Missing Filled Teeth Index (DMFT) was evaluated. Genomic DNA was extracted from the buccal epithelial cells. The four polymorphic SNPs (Bsm I, Taq I, Apa I, and Fok I) in VDR were assessed for both genotypic and phenotypic susceptibilities.

Results

Among the four examined VDR gene polymorphisms, the increased frequency of the CT and CC genotype of the Fok I VDR gene polymorphism was associated with dental caries in 12-year-old adolescent, compared with the controls (X² = 17.813, p ≤ 0.001). Moreover, Fok I polymorphic allele C frequency was significantly increased in the dental caries cases, compared to the controls (X² = 14.144, p ≤ 0.001, OR = 1.730, 95% CI = 1.299–2.303). However, the other three VDR gene polymorphisms (Bsm I, Taq I, and Apa I) showed no statistically significant differences in the caries groups compared with the controls.

Conclusion

VDR-Fok I gene polymorphisms may be associated with susceptibility to permanent tooth caries in Chinese adolescent.