Vitamin D Receptor Gene Polymorphisms Research Articles

A review of vitamin D deficiency and vitamin D receptor polymorphisms in endocrine related disorders.

The endocrine system is a complex network of glands that produce and release hormones that regulate various physiological processes. In the past few decades, the human skin has been identified as an important peripheral endocrine organ that is the main site for the synthesis of vitamin D through exposure to sunlight. Mutations in downstream vitamin D-related gene pathways are associated with disease development. The vitamin D receptor (VDR) gene, which regulates the pleiotropic effects of vitamin D, has been extensively studied in adult populations. Several studies have reported the prevalence of vitamin D deficiency in children and adolescents. With changes in socioeconomic status and lifestyle, vitamin D-deficient individuals are prone to developing the disease at a young age. However, geographical and racial differences affect the association between VDR gene polymorphisms and vitamin D endocrine disorders, explaining the non-consensus effects of polymorphisms and their association with disease development across populations. In this review, we discuss the connection between the vitamin D endocrine system and polymorphisms in the gene encoding VDR in children and adolescents, focusing on its effects on growth, puberty, insulin resistance, and the immune system.

VDR gene polymorphisms rs731236 and rsS2228570 affect vitamin D levels in people of the Kaliningrad region

Vitamin D is an essential micronutrient that is involved in numerous biological processes. It not only keeps bones healthy, but also has a protective effect on the cardiovascular system, the pancreas and fatty tissue. Around 50% of the world’s population suffers from vitamin D deficiency or insufficiency. The prevalence of these diseases is significantly higher in obese people, regardless of age and place of residence. The presence of polymorphisms in the VDR gene (vitamin D receptor) can explain individual differences in the concentration of vitamin D 25(OH) in blood serum. Of particular interest are the effects of the polymorphisms rs731236 and rs2228570 on vitamin levels. Thus, the VDR polymorphism rs731236 is a synonymous substitution, whereas the polymorphism rs2228570 is a non-synonymous substitution. The article investigated the polymorphisms of the VDR gene rs2228570 (T/C), rs731236 (T/C) and determined their association with blood vitamin D levels in people from the Kaliningrad region with different body mass index (BMI). The material for the study was venous blood taken in the morning on an empty stomach from 232 people (mean age 50±13.5 years, 103 men and 129 women). The vitamin D content in the blood was determined by ELISA and the polymorphisms of the VDR gene were analyzed by PCR. In individuals with a BMI 30 kg/m2, changes in the lipid profile and liver function tests were recorded. The vitamin D level did not depend on the BMI of the study participants. Significant changes in blood vitamin D levels were found depending on the distribution of the VDR genotype. Vitamin D levels were higher in individuals with the CC genotype than in the TT and CT genotypes of the rs2228570 polymorphism and did not depend on BMI. In contrast, the presence of the rs731236 polymorphism in the VDR gene is associated with BMI. In obesity, vitamin D levels are therefore only reduced in people with the TT genotype of the rs731236 polymorphism, but not in people with the CC and TC genotype.

VDR gene polymorphism in susceptibility to urolithiasis among the Asian population: A systematic review and meta-analysis

Urolithiasis is one of the most prevalent urinary diseases worldwide. Several studies have reported VDR gene polymorphisms to have a contributing genetic factor in susceptibility to urolithiasis and suggested its possibility of being a good candidate marker for urolithiasis. However, results across numerous studies centred on the relationship between the VDR gene polymorphism and urolithiasis have been inconclusive. To perform a meta-analysis concerning the association between the risk of urolithiasis and VDR gene polymorphismsviz., ApaI, BsmI, FokI, and TaqI among the Asian population. A comprehensive electronic search was conducted to identify published studies that investigates the relationship between four polymorphisms (ApaI, BsmI, FokI and TaqI) in the VDR gene and the risk of urinary stone disease using electronic databases. VDR ApaI and FokI polymorphisms were found to be associated with urolithiasis risk. Results from pooled analysis indicated ApaI aa genotype to be associated with urolithiasis compared to AA or Aa genotypes. In addition, the minor f allele of FokI variant was identified to be the risk allele in susceptibility to urolithiasis while F allele to be protective. Moreover, from the subgroup analysis, the ff genotype of FokI and aa genotype of ApaI were associated with higher risk of urolithiasis among the East Asian but not among the Southwest Asians.

Lack of Association Between BsmI and FokI Polymorphisms of the VDR Gene and Sporadic Colorectal Cancer in a Romanian Cohort-A Preliminary Study.

Colorectal cancer (CRC) is a major public health problem worldwide, currently ranking third in cancer incidence and second in mortality. Multiple genes and environmental factors have been involved in the complex and multifactorial process of CRC carcinogenesis. VDR is an intracellular hormone receptor expressed in both normal epithelial and cancer colon cells at various levels. Several VDR gene polymorphisms, including FokI and BsmI, have been evaluated for their possible association with CRC susceptibility. The aim of our study was to investigate these two SNPs for the first time in Romanian CRC patients. FokI (rs228570 C>T) and BsmI (rs1544410 A>G) were genotyped by real-time polymerase chain reaction (RT-PCR) in 384-well plates using specific TaqMan predesigned probes on a ViiA™ 7 RT-PCR System. A total of 441 subjects (166 CRC patients and 275 healthy controls) were included. No statistically significant difference was observed between CRC patients and controls when we compared the wild-type genotype with heterozygous and mutant genotypes for both FokI (OR 0.85, 95% CI: 0.56-1.28; OR 0.95, 95% CI: 0.51-1.79, respectively) and BsmI (OR 0.97, 95% CI: 0.63-1.49; OR 1.10, 95% CI: 0.65-1.87, respectively) or in the dominant and recessive models. Also, we compared allele frequencies, and no correlation was found. Moreover, the association between these SNPs and the tumor site, TNM stage, and histological type was examined separately, and there was no statistically significant difference. In conclusion, our study did not show any association between FokI and BsmI SNPs and CRC susceptibility in a Romanian population. Further studies including a larger number of samples are needed to improve our knowledge regarding the influence of VDR polymorphism on CRC susceptibility.

Impact of FokI (rs2228570) and BglI (rs739837) polymorphisms in VDR gene on permanent tooth eruption: A cross-sectional study

IntroductionGenetic polymorphisms who disturb the mineral homeostasis during tooth development and eruption are candidate to clarify the molecular mechanisms involved in changes in the tooth eruption chronology. In this study, we evaluate whether the FokI (rs2228570) and BglI (rs739837) polymorphisms in the Vitamin D receptor (VDR) gene are associated with changes in the chronology of eruption of permanent teeth. Material & methodThis cross-sectional study randomly included 353 biologically unrelated children, both sexes, without systemic impairment or syndromes and history of trauma during the primary dentition. One operator perform the oral clinical examination. The tooth was considered erupted if there was a visible minimum of any tooth surface emerging from the mucosa. Genomic DNA was extracted from buccal epithelial cells from saliva samples. Genotyping was performed by Real-Time Polymerase Chain Reactions using TaqMan® technology. The average of the total number of erupted permanent teeth between the genotypes was compared by the Mann-Whitney test and multivariate Generalized Linear Models (GLM) (α = 5 %). β values with Confidence Interval (CI) 95 % were calculated. ResultsThe heterozygous adenine-guanine genotype of the FokI significantly decreases the number of erupted permanent teeth (β = −1.15; CI 95 % = −2.22 to −0.07; p = 0.036). In the stratified analysis for maxillary and mandibular teeth, this genotype was associated with a decrease in the number of erupted maxillary permanent teeth (β = −0.65; CI 95 % = −1.22 to −0.09; p = 0.023). BglI was not associated with permanent teeth eruption. ConclusionThe FokI, but not BglI, in the VDR may delay the eruption of permanent teeth.

The Effect of Vitamin D Supplementation with or without Calcium on Vitamin D Epimer and Metabolites.

A possible role of vitamin D epimers and metabolites in the measurement and response to treatment of vitamin D has been reported recently. Furthermore, the influence of underlying vitamin D receptor (VDR) genetic polymorphisms which have been linked to diseases such as obesity remains unclear. We therefore aimed to examine the influence of vitamin D3 and calcium supplements on vitamin D epimer and metabolite concentrations in subjects with and those without vitamin D receptor (VDR) gene polymorphisms. A total of 277 participants who were part of a randomized intervention trial of vitamin D3 and calcium or a placebo for 6 months had clinical and anthropometric assessments. Blood samples were taken for measurements of vitamin D, epimers and metabolites of vitamin D, four vitamin D receptor gene polymorphism SNPs, namely, BsmI, FokI, TaqI, and ApaI, metabolic and inflammatory markers, and related biochemical variables. Repeated-measures analysis of variance was used to assess the between-group difference in cumulative changes in vitamin D epimers and metabolites at 6 months after adjusting for the presence of the 4 VDR genotypes and allele gene polymorphisms. Overall, 277 participants, with a mean (±SD) age of 41 ± 12 and 204 (74%) of whom were female, were included in the study. We found no statistically significant differences in vitamin D metabolites or (epimers) between male and females or younger subjects compared to those over 40 years of age except in 7C4 BL (p < 0.05). There was a statistically significant difference in 1,25(OH)2D3 concentrations between subjects with and those without genotypes AG and the allele G SNP2_Taql VDR gene polymorphism. Vitamin D3 concentrations were also significantly lower in subjects with the CC SNP3_Apal gene polymorphism compared to those without the CC SNP3 gene. No statistically significant effects were seen on vitamin D epimers and metabolites concentration in response to supplements before or after adjusting for the presence of the 4 VDR genotypes and allele gene polymorphisms. The CC SNP3 gene had statistically significant influence on vitamin D3 levels. Vitamin D and/or calcium supplements, however, had no effects on vitamin D epimer and metabolite concentration before or after adjusting for the presence of the 4 VDR genotypes and alleles.

Vitamin D receptor polymorphisms associate with the efficacy and toxicity of radioiodine-131 therapy in patients with differentiated thyroid cancer.

Radioiodine-131 (I-131) therapy is the common postoperative adjuvant therapy for differentiated thyroid cancer (DTC) However, methods to evaluate the efficacy and toxicity of I-131 on DTC are still lacking. To evaluate the association between vitamin D receptor (VDR) gene polymorphisms and the efficacy and toxicity of I-131 in DTC patients. A total of 256 DTC patients who received I-131 therapy were enrolled. The patients were divided into effective group and ineffective group. 4 single nucleotide polymorphisms (SNPs) (rs7975232, rs731236, rs1544410 and rs10735810) of VDR were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) Cell counting kit-8 (CCK-8) and flow cytometry were used to detect the proliferation and apoptosis of thyroid cancer cells. Patients in effective group had more CC genotype of rs7975232 and GG genotype of rs10735810 compared with patients in ineffective group They were also independent factors for influencing the efficacy of I-131. PTC-1 and FTC-133 cells transfected with CC genotype of rs7975232 showed lower proliferative activity and higher apoptosis rate after being treated with I-131 In addition, patients with CC genotype at rs7975232 had fewer adverse reactions after I-131 treatment. VDR gene polymorphisms may be associated with the efficacy and toxicity of I-131 in DTC patients, which will help to personalize the treatment for patients.

Association between vitamin D metabolism gene polymorphisms and schizophrenia.

Schizophrenia (SZ) is a multifactorial and neurodegenerative disorder that results from the interaction between genetic and environmental factors. Notably, hundreds of single nucleotide polymorphisms (SNPs) are associated with the susceptibility to SZ. Vitamin D (VD) plays an essential role in regulating several genes important for maintaining brain function and health. To the best of the authors' knowledge, no studies have yet been conducted on the association between the VD pathway and patients with SZ. Therefore, the present study aimed to assess the potential association between eight SNPs in genes related to the VD pathway, including CYP2R1, CYP27B1, CYP24A1 and VDR among patients with SZ. A case-control study was conducted, involving a total of 400 blood samples drawn from 200 patients and 200 healthy controls. Genomic DNA was extracted and variants were genotyped using the tetra-amplification refractory mutation system-polymerase chain reaction method. The present study revealed statistically significant differences between patients with SZ and controls regarding the genotypes and allele distributions of three SNPs [CYP2R1 (rs10741657), CYP27B1 (rs10877012) and CYP24A1 (rs6013897) (P<0.0001)]. The AA genotype of rs10741657 was identified to be associated with SZ (P<0.0001) and the frequency of the A allele was higher in patients with SZ (P<0.0001) compared with the control group. Similarly, the TT genotype of rs10877012 was revealed to be associated with SZ (P<0.0001) and the T allele was more frequent in patients with SZ (P<0.0001) than in the control group. Moreover, the AA genotype of rs6013897 was revealed to be associated with SZ (P<0.0001), although no significant difference was detected between the two groups regarding the A allele (P=0.055). VDR (rs2228570, rs1544410, rs731236 and rs7975232) and CYP27B1 (rs4646536) gene polymorphisms did not exhibit a significant association with SZ. While the studied SNPs revealed promising discriminatory capacity between patients with SZ and controls, the rs10741657 SNP exhibited the most optimal area under the curve value at 0.615. A logistic model was applied considering only the significant SNPs and VD levels, which revealed that rs6013897 (T/A) and VD may have protective effects (0.267, P<0.001; 0.888, P<0.001, respectively). Moreover, a low serum VD level was highly prevalent in patients with SZ compared with the controls. Based on this finding, an association between serum 25(OH)D and SZ could be demonstrated. The present study revealed that CYP2R1 (rs10741657), CYP27B1 (rs10877012) and CYP24A1 (rs6013897) gene SNPs may be associated with SZ susceptibility.

Association of Vitamin D receptor gene polymorphisms (FokI, ApaI, TaqI), metabolic features and susceptibility to polycystic ovary syndrome: a preliminary single center case-control study

Research questionAre the combined genotypes and haplotypes of VDR gene polymorphisms (FokI, ApaI, TaqI) associated with PCOS susceptibility and metabolic features of the disease? DesignWe performed a case-control study, including 46 women with PCOS and 48 controls. Genotypes of VDR genes were determined using the PCR-RFLP (restriction fragment length polymorphism) method. In all women, the waist circumference, parameters of lipid and glucose metabolism were evaluated. ResultsPCOS group presented higher waist circumference and visceral adiposity index (VAI) levels compared to controls. Total cholesterol, LDL-C and triglycerides had higher values in PCOS women. VDR-FokI C/C (F/F) genotype had significantly higher odds of PCOS (adjusted OR = 6.27, 95% CI: 1.53-25.65). VDR-Apal was associated with susceptibility to PCOS in the dominant model, the variant genotype (A/C-A/A) (A/a- a/a) had higher odds of PCOS than the wild genotype C/C (A/A) (adjusted OR = 3.15, 95% CI: 1.07-9.32). Haplotype analysis revealed that T-C- T (f-A-T) haplotype was statistically associated with lower odds of PCOS (adjusted OR = 0.10, 95% CI: 0.01-0.95). PCOS women with VDR-Fokl T/T (f/f) genotype had lower fasting glucose and higher VAI levels compared to C/T (Ff) or C/C (F/F) genotype. ConclusionThe present findings suggest the association between FokI and ApaI polymorphisms and PCOS susceptibility. Moreover, T/T (f/f) genotype of VDR-FokI could be a marker of decreased fasting glucose in PCOS. TaqI polymorphism did not reveal a relationship with PCOS susceptibility in our study population.

Association of vitamin D status and vitamin D receptor polymorphism in diabetic foot ulcer patients: A prospective observational study in a South-Indian tertiary healthcare facility.

Objective of the study was to find the association of vitamin D receptor (VDR) polymorphisms (Fokl, Taql and Apal) with vitamin D levels in diabetic foot ulcer (DFU) patients in South India. In this case-control study, plasma vitamin D levels and VDR genotype frequencies of 70 cases (DFU patients) were compared with 70 diabetic (diabetes mellitus [DM] [non-DFU]) patients and 70 apparently healthy controls (HC) from South India. Plasma vitamin D levels were measured using the ELISA technique, and genotyping of VDR polymorphisms was carried out using real-time polymerase chain reaction. Logistic regression was used to find the association between DFU versus HC and DFU versus DM traits. Association analysis was performed based on additive, dominant and recessive models with age and gender as covariates. A 45.7% of DFU patients have sufficient vitamin D levels than 48.6% and 40% of DM patients and HC, respectively. Linkage disequilibrium analysis for DFU versus HC and DFU versus DM traits shows that single nucleotide polymorphisms (SNPs) Taq1 (rs731236) and Apal (rs7975232) are in strong linkage disequilibrium in DFU patients. The alleles and genotype frequencies were similar in all three groups. Although the additive model does not show statistical significance, age and sex correlate with the three SNPs (Fokl, Taql and Apal). No association was found between VDR gene polymorphisms and vitamin D levels in DFU patients in Southern India. On the other hand, age and sex correlate with the three SNPs.

Association between Vitamin D Receptor Polymorphisms, Tight Junction Proteins and Clinical Features of Adult Patients with Atopic Dermatitis.

Few studies have explored the intricate connections between vitamin D receptor (VDR) gene polymorphisms, VDR, tight junction (TJ) protein expression and clinical features of atopic dermatitis (AD). From 43 adult AD patients, VDR polymorphisms were genotyped from peripheral blood samples using polymerase chain reaction-restriction fragment length polymorphism. VDR, occludin, claudin-1 and ZO-1 protein expression from skin lesion biopsies were assessed by immunohistochemistry. The A1012G heterozygous VDR polymorphism exhibited a lower odds ratio (OR) for juvenile AD onset (OR: 0.046, 95% CI 0.004-0.51, p=0.012). In contrast, the presence of ≥2 homozygous VDR polymorphisms were significantly associated with positive skin prick test (SPT) (10/20, 50%) vs. negative SPT (1/23, 4.3%; p=0.0003). The most highly expressed TJ proteins in lesions of AD patients were claudin-1 and zonulin-1 (ZO-1), while VDR and occludin were less prevalent. A significant correlation was observed between ZO-1 expression and a body mass index ≥30 kg/m2 (OR: 12.1, 95% CI 1.06-137.9, p=0.045). Claudin-1 expression was associated with a positive SPT (OR: 8.23, 95% CI 1.04-65.5, p=0.046) and serum 25(OH)D levels were negatively correlated with ZO-1 expression (rho= -0.43, p=0.0058). This study provides novel insights into the relationship between VDR gene polymorphisms, VDR, TJ protein expression, and clinical features in adult AD patients, highlighting a significant role of vitamin D in the pathophysiology of this disease.

VDR Gene Polymorphisms (BsmI, FokI, TaqI, ApaI) in Total Hip Arthroplasty Outcome Patients.

A total hip arthroplasty (THA) can improve quality of life, but loosening of the hip prosthesis is a complex problem in which vitamin D may also play a role. The Vitamin D Receptor (VDR) is involved in the response of cells to the action of vitamin D, and its genetic variability raises the question of whether individual differences could influence the risk of prosthesis loosening. The aim of this study was to investigate the relationship between VDR single nucleotide polymorphisms (SNPs) (ApaI, BsmI, FokI and TaqI) and the serum VDR and 25(OH)D levels in three groups of patients: (1) arthroscopy patients after THA without loosening of the prosthesis (CA-Control Arthroplasty), (2) patients after THA with loosened hip prostheses (L-Loosening) and (3) the control group (C-Control). Our results suggest that the genotypes tt of TaqI, BB of BsmI, and FF of FokI may influence the VDR effect in patients with loosened protheses. Our results showed that the ACAC haplotype (AtBF) was over two times more frequent in the L group than in CA + C: OR =2.35 [95% CI 1.44-3.83; p = 0.001]. There was no significant correlation between the VDR and serum 25(OH)D levels, but there were differences between studied groups.

The Effects of MMP3 (rs679620) and VDR (rs731236) Gene Polymorphisms on Dental Caries: A Pilot Study.

Caries formation is a process affected by various factors. Studies have shown that genetic factors also play a role in caries formation. The aim of our study is to examine the effects of matrix metalloproteinase (MMP)3 (rs679620) and vitamin D receptor (VDR) (rs731236) gene polymorphisms on caries formation. Following routine oral examinations in individuals aged between 20 and 44 years, the diagnosis was made according to the decayed, missing, and filled teeth (DMFT) index, and experimental group was defined as "high caries risk" (DMFT ≥ 14, n = 28), and the control group as "no caries" (DMFT = 0, n = 28). Plaque index and bleeding on probing were measured from participants with a detailed anamnesis. Periodontally healthy individuals with less than 10% bleeding on probing were included in the study (n = 56). After DNA isolation from blood samples taken from the participants, the genotyping of MMP3 (rs679620) and VDR (rs731236) gene polymorphisms were determined using the real-time polymerase chain reaction technique. Data were analyzed with IBM SPSS V23.0. Data distribution was evaluated with Kolmogorov-Smirnov's test. Pearson's chi-square test was used to compare categorical data according to groups. The results were evaluated using a significance level of p < 0.05. Regarding MMP3 and VDR gene polymorphisms, there was a statistically significant difference between the groups in terms of MMP3 (rs679620) (p < 0.001). There was no statistically significant difference between the VDR (rs731236) genotype distributions of the groups (p = 0.659). Within the limits of this study, MMP3 rs679620 gene polymorphism may have an effect on caries formation.

The Role of Vitamin D and Vitamin D Receptor Gene Polymorphisms in the Course of Inflammatory Bowel Disease in Children.

Background: The etiopathogenesis of inflammatory bowel disease (IBD) is still unclear. Prior studies suggest genetic components that may influence the incidence and severity of the disease. Additionally, it was shown that low levels of serum vitamin D may have an impact on the clinical course of the disease due to its effect on the immunological system. Methods: We aimed to investigate the correlation between the incidence of vitamin D receptor (VDR) gene polymorphisms (rs11568820, rs10735810, rs1544410, rs7975232, and rs731236, commonly described as Cdx2, FokI, Bsm, ApaI, and TaqI, respectively) and vitamin D concentration with the clinical course of IBD (disease activity, extent of the intestinal lesions). Data were obtained from 62 patients with IBD (34 with Crohn's disease, 28 with ulcerative colitis), aged 3-18 years, and compared with controls (N = 47), aged 8-18 years. Results: Although there was no difference in the incidence of individual genotypes between the study groups (IBD, C) in all the polymorphisms examined, we described a significant increase in the chance of developing IBD for heterozygotes of Cdx2 (OR: 2.3, 95% CI 0.88-6.18, p = 0.04) and BsmI (OR: 2.07, 95% CI 0.89-4.82, p = 0.048) polymorphisms. The mean serum 25OHD level in patients with IBD was significantly higher compared with the controls (19.87 ng/mL vs. 16.07 ng/mL; p = 0.03); however, it was still below optimal (>30 ng/mL). Furthermore, a significant correlation was found between vitamin D level and TaqI in patients with IBD (p = 0.025) and patients with CD (p = 0.03), as well as with the BsmI polymorphism in patients with IBD (p = 0.04) and patients with CD (p = 0.04). A significant correlation was described between the degree of disease activity and genotypes for the FokI polymorphism in patients with UC (p = 0.027) and between the category of endoscopic lesions and genotypes for the Cdx2 polymorphism also in patients with UC (p = 0.046). Conclusions: The results suggest a potential correlation of VDR gene polymorphism with the chance of developing IBD, and the clinical course of the disease requires further studies in larger group of patients. Vitamin D supplementation should be recommended in both children with inflammatory bowel disease and in healthy peers.

Gene Variants of Vitamin D Receptor (TaqI T &gt; C (rs731236) and BsmI G &gt; A (rs1544410) in Urolithiasis

Background: Urolithiasis is the most prevalent uronephrologic disorder caused by genetic, environmental factors, and metabolic defects. Objectives: The present study aimed to find a possible association between the vitamin D receptor (VDR) TaqI and the BsmI gene polymorphisms in relation to the serum levels of calcium (Ca) and vitamin D and the risk of urolithiasis. Methods: This case-control study was conducted on 68 children with urolithiasis and 67 healthy controls for the VDR gene polymorphisms using the polymerase chain reaction-restriction length polymorphism method. Results: The frequency of TaqI C allele was 36% in patients compared to 32.1% in controls (P = 0.49). A significantly higher frequency of the TaqI CC genotype was found among patients in the age group &gt; 5 to 10 years. No significant difference was detected in the frequency of the BsmI A allele between patients (41.9%) and controls (42.5%, P = 0.91). However, a significantly lower frequency of the BsmI AA genotype was detected compared to those patients with Ca levels of &gt; 10.8 mg/dL among patients with Ca levels of ≤ 10.8 mg/dL. Conclusions: Based on the results, a lack of an association between the VDR TaqI and BsmI polymorphisms with the risk of urolithiasis among children from Western Iran. However, a higher frequency of the TaqI CC genotype was found in the age group &gt; 5 to 10 years. In addition, lower levels of Ca in patients were related to a significantly lower frequency of the BsmI AA genotype. The VDR gene BsmI polymorphism might affect the calcium level and the calcium metabolism in urolithiasis.

Vitamin D Receptor (VDR) Gene Polymorphisms and High-Turnover Renal Osteodystrophy or Secondary Hyperparathyroidism in End-Stage Renal Disease: A Systematic Review.

Chronic kidney disease (CKD) and end-stage renal disease (ESRD) are often complicated by high-turnover renal osteodystrophy (HTRO) and secondary hyperparathyroidism (SHPT), characterized by disturbances in mineral metabolism and skeletal abnormalities. Genetic variations within the vitamin D receptor (VDR) gene, known as VDR gene polymorphisms, have been implicated in modulating the susceptibility to HTRO and SHPT. This systematic review aims to evaluate the existing literature on the association between VDR gene polymorphisms and the development of these complications in ESRD and hemodialysis patients. A comprehensive literature search across multiple databases was conducted, and studies investigating VDR gene polymorphisms and HTRO or SHPT in ESRD or hemodialysis patients were included. The included studies examined various VDR gene polymorphisms, such as BsmI, ApaI, TaqI, and FokI, and their associations with clinical outcomes like parathyroid hormone (PTH) levels, bone mineral density, and the development of SHPT or HTRO. The findings suggest that certain VDR gene polymorphisms, notably the ApaI "aa"genotype, BsmI "bb"genotype, TaqI "tt"genotype, and FokI variant, may contribute to the pathogenesis of SHPT and HTRO by affecting PTH levels, bone turnover markers, and vitamin D sensitivity. However, the studies had relatively small sample sizes and were conducted in different populations, limiting generalizability. Further larger-scale studies, functional investigations, and exploration of gene-environment interactions are warranted to elucidate the underlying mechanisms and facilitate personalized treatment approaches for CKD and ESRD patients with mineral and bone disorders.

Vitamin D status and VDR gene polymorphisms in patients with growth hormone deficiency: A case control Tunisian study

IntroductionGrowth Hormone Deficiency (GHD) is a rare disease marked by a complete or partial reduction in the production of growth hormone. Vitamin D deficiency is frequent and may be associated with several pathologies. However, the association between GHD and vitamin D deficiency has not been extensively studied. This study aimed to analyse VDR gene polymorphisms related to vitamin D status to ensure better care for patients with GHD. Material and methodsA case-control study was conducted at the Children's Hospital of Tunis in collaboration with the Farhat Hached's Hospital of Sousse, including patients with GHD and healthy subjects. Genetic analysis of the VDR gene polymorphisms was performed using PCR-RFLP technique. Haplotypes were examined with Haploview software, while statistical analyses were carried out using SPSS and R programming language. ResultsOur study revealed significant differences in vitamin D (p = 0, 049) and calcium concentrations between patients and healthy subjects, which were lower in the GHD group (p = 0,018). A comparison of allelic and genotypic frequencies of the five polymorphisms indicated an association between the FokI polymorphism and GHD. Furthermore, significant difference was observed between the ApaI genotypes and PTH (p = 0,019) and ALP (p = 0,035). FokI genotypes were associated with phosphorus (p = 0,021). Additionally, One haplotype, CTAGT, exhibited a significant difference between the patients and healthy subjects (p = 0,002). ConclusionOur study findings indicate that hypovitaminosis D is common among patients with GHD, even when undergoing treatment with rhGH. This underscores the critical importance of vitamin D supplementation during treatment.

Gene detection of VDR BsmI locus and its approteins, genes and growthplication in rational drug use in patients with osteoporosis.

Aim: This paper determines the polymorphism distribution of the VDR BsmI gene in 350 patients and provides medication recommendations for osteoporosis based on detection results. Materials & methods: Chi-square tests compared genotype and allele frequencies with other populations. Results: Genotype frequencies were 91.66bb, 8.72Bband 0.21% BB, with allelic frequencies of 95.43b and 4.57% B, adhering to Hardy-Weinberg equilibrium. These findings suggest that VDR gene polymorphisms, particularly at the BsmIlocus, play an essential role in bone health and osteoporosis treatment. Genotype-based drug selection reduced adverse reactions from 14 to twocases. Conclusion: These findings improve clinical treatment efficacy and guide rational drug use for osteoporosis patients.

TaqI polymorphism of VDR gene in colorectal cancer and Crohn’s disease patients

To study the relation of TaqI polymorphism of VDR gene with age, sex and the disease phenotype in patients with colorectal cancer (CRC) and Crohn’s disease (CD) from western regions of Ukraine. Fifty six patients with CRC, 46 patients with CD and 65 control individuals were included in this research. Assessment of TaqI polymorphism was performed using PCR-RFLP method. The genotype-phenotype association for this polymorphism was analyzed. The frequency of tt genotype in patients with CRC is 0.107 and among the control group is 0.138, OR (95% CI 0.248-2.246). The ratio of genotypes TT:Tt:tt in patients with CRC and in control was 37.5%:51.8%:10.7% and 44.6%:41.6%:13.8%. In men with Tt genotype the average age of CRC onset was 57.6 ± 3.6 years, in women with TT genotypethe mean age of the disease onset was 54.5 ± 4.5 years. The frequency of tt genotype in the patients with CD is 0.217 and among the control group is 0.138, OR (95% CI 0.640–4.666). The Tt genotype was detected in a half of patients with CD and TT genotype was found more frequently in control.The ratio of genotypes in men and women with CD was 38.0%:38.0%:24.0% and 20.0%:60.0%:20.0%. Among patients with CD, who underwent surgery, 33.3% individuals were carriers of tt genotype. It was confirmed no statistically significant difference in the allele frequencies and genotype distributions of Taq1 mutation in patients with CRC and CD in comparison to control group. The ratio of men and women with Tt genotype by groups of B1-B3 forms of CD behaviour according to the Montreal classification is differs, in particular, women with Tt genotype are four times more likely to have the B1 form. A study of Taq1 mutation might contribute to the identification of the groups that are at the greatest risk of severe form of CD.

Unraveling the role of the vitamin D-VDR pathway in pemphigus vulgaris from Tunisian patients

Vitamin D dysregulation has been recognized as a factor that may cause or aggravate autoimmunity. Vitamin D deficiency was found to be common in pemphigus vulgaris (PV) in different populations. This study aimed to investigate the vitamin D-VDR pathway in PV in the Tunisian population.A serological study was carried out to determine the vitamin D status in newly diagnosed PV patients. CYP27B1, CYP24A1 and VDR mRNA expression was assessed using quantitative real-time PCR in peripheral blood mononuclear cells (PBMC) from untreated newly diagnosed and treated PV patients. In addition, a genetic study was accomplished on VDR polymorphisms to investigate the changes in VDR gene expression. Overall, the serological study confirmed the hypovitaminosis D in newly diagnosed PV patients. Vitamin D-VDR pathway gene expression showed downregulation of CYP27B1 and CYP24A1 mRNA in first-discovery patients compared to healthy controls, while VDR mRNA was highly expressed in newly diagnosed PV patients. Moreover, CYP27B1, CYP24A1 and VDR mRNA were significantly upregulated in chronic disease severity groups compared to mild disease groups. The genetic study showed low VDR gene expression in carriers of FokI > CC genotype, which was more frequent among PV patients, and FokI > C-TaqI > C-ApaI > A-polyA > A16 haplotype, suggesting that the VDR gene polymorphisms testing can provide useful information for PV treatment decision-making.In conclusion, our findings underline the impact of vitamin D-VDR pathway disruption in the PV pathophysiology in Tunisian patients.