Indian ASD probands with 25(OH)D and vitamin D binding protein deficiency exhibited higher severity.

The severity of autism spectrum disorder (ASD) shows wide variations, though the reason remains unclear. Vitamin D (VitD) deficiency is considered a risk factor for ASD and its supplementation was reported to reduce symptom severity. Since VitD, either synthesized in the skin or absorbed from the food, is transported to the liver by the vitamin D binding protein (DBP), we have analyzed DBP genetic polymorphisms [rs7041 (A/C), rs4588 (G/T), and rs3755967 (C/T)] affecting DBP function [Case = 411; Control = 397], levels of plasma 25(OH)D and DBP [Case = 25; Control = 26], and DBP mRNA expression [Case = 74; Control = 44] in a group of Indo-Caucasoid ASD probands and neurotypical subjects. ASD probands with rs7041'CC', rs4588 'TT', and rs3755967 'TT' genotypes exhibited higher scores for a few traits. Scores for Imitation and Listening response were also higher in the presence of the "A-T" haplotype (rs7041-rs4588). Plasma 25(OH)D and DBP levels as well as DBP mRNA expressions were significantly lower in the ASD probands as compared to the neurotypical subjects. We infer that DBP deficiency, in the presence of risk genetic variants, could be one of the reasons for the reported 25(OH)D deficiency of the ASD probands.

Relation of T Cell Profile with Vitamin D Receptor and Vitamin D-Binding Protein Gene Polymorphisms in Atopy.

Atopic diseases, including atopic dermatitis (AD) and allergic asthma (AA), are characterized by complex immune responses involving various T cells subsets and their cytokine profiles. It is assumed that single nucleotide polymorphisms (SNPs) in the Vitamin D receptor (VDR) gene and the Vitamin D-binding protein (GC) gene are related to the action of Vitamin D and, consequently, play a role in regulating the immune response. However, there is not enough data to unequivocally support the hypothesis about the relationship between T cells profile and VDR or GC SNPs. Two hundred sixty-six subjects (aged > 18 years) were involved in the study: 100 patients with mild or moderate AD, 85 patients with mild or moderate AA, and 81 healthy individuals. Blood cell counts were determined by standard methods. Flow cytometric analysis was used to evaluate CD4+ T-helper (Th) cell subtypes: Th2, Th1, Th17, and T regulatory (Treg) cells in peripheral blood. Measurements of cytokines, total immunoglobulin E (IgE), and Vitamin D levels in serum were evaluated by ELISA. Significantly higher levels of Th1, Th2, and Th17 cells, along with lower levels of Tregs, were found in patients with atopic diseases compared to healthy individuals. Additionally, higher serum levels of interleukin (IL) 5, IL-17A, and transforming growth factor-ß1 (TGF-ß1), as well as lower levels of IL-10, were observed in patients with atopic diseases than in control. The study established associations between VDR SNPs and immune profiles: the AA genotype of rs731236 was associated with increased Th2 and Th17 cells and a higher Th1/Th2 ratio; the GG genotype of rs731236 was linked to decreased serum IL-10 and TGF-ß1 levels; and the TT genotype of rs11168293 was associated with increased IL-10 levels. Additionally, the GG genotype of GC gene SNP rs4588 was associated with reduced Th2 and Th17 lymphocytes, while the TT genotype of rs4588 was linked to decreased IL-10 levels. Furthermore, the CC genotype of rs7041 was associated with higher levels of Th2, Th17, IL-10, and IL-35, as well as reduced levels of TGF-ß1, while the GG genotype of rs3733359 was associated with reduced IL-10 levels. In conclusion, our study demonstrates that the Vitamin D receptor gene single nucleotide polymorphisms rs731236 and rs11168293, along with polymorphisms in the Vitamin D-binding protein gene (rs4588, rs7041, rs3733359), are significantly associated with variations in T cell profiles in atopy. These variations may play a crucial role in promoting inflammation and provide insight into the genetic factors contributing to the pathogenesis of atopy.

25-Hydroxyvitamin D, Vitamin D Binding Protein and Gestational Diabetes Mellitus: A Two-Sample Mendelian Randomization Study.

BACKGROUND: Numerous studies have examined whether vitamin D is associated with gestational diabetes mellitus (GDM). Nevertheless, it is still challenging to determine the causality, due to a number of shortcomings in observational research and randomized controlled trials. OBJECTIVE: Mendelian randomization (MR) with two samples was conducted to investigate the potential causative association between 25-hydroxyvitamin D (25(OH)D), vitamin D binding protein (VDBP) and GDM risk. METHODS: Publicly accessible summary data from independent cohorts were used for two-sample MR. For 25(OH)D, we obtained data from UK Biobank, IEU and EBI, then performed a meta-analysis to enhance the statistical power (via METAL); for VDBP, data were obtained from the INTERVAL study; for GDM, data were obtained from FinnGen. The inverse variance weighted (IVW) approach was performed as the main analysis, together with several sensitivity analyses, such as MR-Egger, maximum likelihood, weighted median, and weighted mode. RESULTS: The IVW results revealed a weak negative causal connection between 25(OH)D and GDM risk [OR (95% CI) = 0.71 (0.50, 0.99), p = 0.046]. However, the causal association was unstable according to sensitivity analyses, and Cochran's Q test revealed significant heterogeneity. After removing BMI-related IVs, the causal association between 25(OH)D and GDM disappeared [OR (95% CI) = 0.76 (0.55, 1.06), p = 0.101]. In addition, our study found no proof to support the assumption that VDBP level was related to GDM risk causally [OR (95% CI) = 0.98 (0.93, 1.03), p = 0.408]. CONCLUSIONS: According to this study, a weak negative causal association between 25(OH)D and GDM risk was found, while we had little proof to support the link between VDBP and GDM. To further explore whether total or free 25(OH)D levels and GDM are causally related, GWAS data with an emphasis on women of reproductive age and other ethnic groups are required.

Effects of High-Dose Vitamin D Supplementation on Placental Vitamin D Metabolism and Neonatal Vitamin D Status.

Vitamin D (vitD) deficiency (25-hydroxy-vitamin D < 50 nmol/L) is common in pregnancy and associated with an increased risk of adverse pregnancy outcomes. High-dose vitD supplementation is suggested to improve pregnancy health, but there is limited knowledge about the effects on placental vitD transport and metabolism and the vitD status of newborns. Comparing the current standard maternal supplementation, 10 µg/day to a 90 µg vitD supplement, we investigated placental gene expression, maternal vitD transport and neonatal vitD status. Biological material was obtained from pregnant women randomized to 10 µg or 90 µg vitD supplements from week 11-16 onwards. Possible associations between maternal exposure, neonatal vitD status and placental expression of the vitD receptor (VDR), the transporters (Cubilin, CUBN and Megalin, LRP2) and the vitD-activating and -degrading enzymes (CYP24A1, CYP27B1) were investigated. Maternal vitD-binding protein (VDBP) was determined before and after supplementation. Overall, 51% of neonates in the 10 µg vitD group were vitD-deficient in contrast to 11% in the 90 µg group. High-dose vitD supplementation did not significantly affect VDBP or placental gene expression. However, the descriptive analyses indicate that maternal obesity may lead to the differential expression of CUBN, CYP24A1 and CYP27B1 and a changed VDBP response. High-dose vitD improves neonatal vitD status without affecting placental vitD regulation.

Association of rs4588 polymorphism in vitamin D binding protein gene with polycystic ovarian syndrome in Iranian women: a case-control study.

OBJECTIVE: Vitamin D deficiency and variations in the vitamin D binding protein (VDBP) gene may play a role in the development of Polycystic ovary syndrome (PCOS). This study aims to investigate the association of the rs4588 polymorphism with PCOS in Iranian women, as well as its association with infertility and recurrent pregnancy loss (RPL) in these patients. RESULTS: The analysis revealed statistically significant differences in the distributions of genotypes and alleles of the rs4588 polymorphism among the three groups (p < 0.0001). The AC genotype and A allele showed an association with an elevated risk of PCOS and infertility. In this study, no association was found between genotypes and alleles of the rs4588 polymorphism and the risk of RPL in women with PCOS. Subjects with the AA or AC genotype exhibited significantly higher levels of LDL compared to those with the CC genotype.

Investigating Vitamin D-Binding Protein's Role in Childhood Health and Development.

Vitamin D-binding protein (DBP), also known as Gc-globulin, is a protein that affects several physiological processes, including the transport and regulation of vitamin D metabolites. Genetic polymorphisms in the DBP gene have a significant impact on vitamin D levels and may have implications for disease risk. DBP polymorphisms are linked to differential immune responses, which could influence the onset of juvenile diseases. This narrative review examines the various roles of DBP, with a focus on bone health, immunological regulation, and lipid metabolism in children. Chronic disorders affected by DBP polymorphisms include bone abnormalities, autoimmune diseases, cardiovascular issues, childhood asthma, allergies, cystic fibrosis, acute liver failure, celiac disease, inflammatory bowel disease, and chronic kidney disease. Future research should focus on identifying the processes that underpin the many roles that DBP plays and developing customized therapeutics to improve health outcomes in the juvenile population.

Relationship between Vitamin D3 Deficiency, Metabolic Syndrome and VDR, GC, and CYP2R1 Gene Polymorphisms.

The presence of vitamin D3 deficiency associated with the presence of metabolic syndrome (MS) has important public health effects. This study aims to investigate the relationship between vitamin D3 deficiency, MS and vitamin D3 receptor (VDR), GC Vitamin D binding protein (GC), and cytochrome P450 family 2 subfamily R member 1 (CYP2R1) gene polymorphisms, and genes whose encoded proteins are responsible for vitamin D3 metabolism and transport. A total of 58 participants were included in this study (age 39 ± 12 years) and were selected over a 12-month period. They were divided into four groups, depending on the presence of polymorphisms in VDR, GC, and CYP2R1 genes and their weight status. At baseline, in months 3, 6, and 12, biochemical parameters including 25(OH)D3, total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides, and homeostatic model assessment (HOMA index), the insulin resistance indicator were measured. Our results show that all subjects in the polymorphism group supplemented with vitamin D3 reached an optimal level of vitamin D3 associated with high concentrations of 25(OH)D3. Weight loss was most significant in patients in the POW group (overweight patients).

Unmeasurable low vitamin D levels caused by a novel, homozygote loss-of-function variant in the group-specific component gene.

A 29-year-old female, born to consanguineous parents, was found with unmeasurable levels of vitamin D (<10 nmol/L) after routine biochemical screening during her first pregnancy. She did not respond to either oral or intramuscular vitamin D supplementation and was an otherwise healthy young woman, with no signs of rickets, osteomalacia, osteoporosis, or secondary hyperparathyroidism. Western blot analysis revealed total lack of vitamin D binding protein, and next generation sequencing confirmed a novel, pathogenic homozygote loss-of-function mutation in exon 13 of the group-specific component gene, that encodes the poly A tail for vitamin D binding protein. She was therefore diagnosed with hereditary DBP deficiency, and vitamin D supplementation was diminished to life-long regular vitamin D supplementation (25 µg per day). This case is extremely interesting, as it expands our knowledge of vitamin D physiology and supports the free hormone hypothesis, given that the patient was asymptomatic despite no measurable levels of vitamin D.

Vitamin D regulates microbiome-dependent cancer immunity.

A role for vitamin D in immune modulation and in cancer has been suggested. In this work, we report that mice with increased availability of vitamin D display greater immune-dependent resistance to transplantable cancers and augmented responses to checkpoint blockade immunotherapies. Similarly, in humans, vitamin D-induced genes correlate with improved responses to immune checkpoint inhibitor treatment as well as with immunity to cancer and increased overall survival. In mice, resistance is attributable to the activity of vitamin D on intestinal epithelial cells, which alters microbiome composition in favor of Bacteroides fragilis, which positively regulates cancer immunity. Our findings indicate a previously unappreciated connection between vitamin D, microbial commensal communities, and immune responses to cancer. Collectively, they highlight vitamin D levels as a potential determinant of cancer immunity and immunotherapy success.

Vitamin D-associated genetic variants in the Brazilian population: Investigating potential instruments for Mendelian randomization. / Variantes genéticas asociadas con la vitamina D en la población brasileña: investigación de potenciales instrumentos para aleatorización mendeliana

INTRODUCTION: Vitamin D is required for bone and mineral metabolism and participates in the regulation of the immune response. It is also linked to several chronic diseases and conditions, usually in populations of European descent. Brazil presents a high prevalence of vitamin D deficiency and insufficiency despite the widespread availability of sunlight in the country. Thus, it is important to investigate the role of vitamin D as a risk factor for disease and to establish causal relationships between vitamin D levels and health-related outcomes in the Brazilian population. OBJECTIVE: To examine genetic variants identified as determinants of serum vitamin D in genome-wide association studies of European populations and check whether the same associations are present in Brazil. If so, these single nucleotide polymorphisms (SNPs) could be developed locally as proxies to use in genetically informed causal inference methods, such as Mendelian randomization. MATERIALS AND METHODS: We extracted SNPs associated with vitamin D from the genomewide association studies catalog. We did a literature search to select papers ascertaining these variants and vitamin D concentrations in Brazil. RESULTS: GC was the gene with the strongest association with vitamin D levels, in agreement with existing findings in European populations. However, VDR was the most investigated gene, regardless of its non-existing association with vitamin D in the genomewide association studies. CONCLUSIONS: More research is needed to validate sound proxies for vitamin D levels in Brazil, for example, prioritizing GC rather than VDR.

Introducción. La vitamina D es necesaria para el metabolismo óseo y mineral, y participa en la regulación de la respuesta inmunitaria. También está relacionada con enfermedades crónicas en poblaciones europeas. En Brasil, existe una prevalencia elevada de deficiencia e insuficiencia de vitamina D, a pesar de la amplia disponibilidad de luz solar. Por lo tanto, es importante investigar el papel de la vitamina D como factor de riesgo de diversas enfermedades y establecer relaciones causales entre los niveles de vitamina D y los problemas de salud en la población brasileña. Objetivo. Examinar variantes genéticas relacionadas con la vitamina D sérica en estudios de asociación genómica de poblaciones europeas y comprobar si estas mismas están presentes en Brasil. De ser así, estos SNPs podrían utilizarse como proxies en métodos de inferencia causal, tales como la aleatorización mendeliana. Materiales y métodos. A partir del catálogo de estudios de asociación de genoma completo se extrajeron SNPs relacionados con los niveles de vitamina D. Luego se hizo una búsqueda bibliográfica para identificar los artículos que evaluaran estos SNPs y la concentración de vitamina D en Brasil. Resultados. GC fue el gen más fuertemente asociado con los niveles de vitamina D, en concordancia con los resultados existentes en poblaciones europeas. Sin embargo, el gen VDR fue el más investigado, aunque no esté vinculado con la vitamina D en los estudios de asociación de genoma completo. Conclusiones. Se necesita más investigación para validar proxies genéticos de los niveles de vitamina D en Brasil y se recomienda priorizar el gen GC en lugar de VDR.

Phenomewide Association Study of Health Outcomes Associated With the Genetic Correlates of 25 Hydroxyvitamin D Concentration and Vitamin D Binding Protein Concentration.

While it is known that vitamin D deficiency is associated with adverse bone outcomes, it remains unclear whether low vitamin D status may increase the risk of a wider range of health outcomes. We had the opportunity to explore the association between common genetic variants associated with both 25 hydroxyvitamin D (25OHD) and the vitamin D binding protein (DBP, encoded by the GC gene) with a comprehensive range of health disorders and laboratory tests in a large academic medical center. We used summary statistics for 25OHD and DBP to generate polygenic scores (PGS) for 66,482 participants with primarily European ancestry and 13,285 participants with primarily African ancestry from the Vanderbilt University Medical Center Biobank (BioVU). We examined the predictive properties of PGS25OHD, and two scores related to DBP concentration with respect to 1322 health-related phenotypes and 315 laboratory-measured phenotypes from electronic health records. In those with European ancestry: (a) the PGS25OHD and PGSDBP scores, and individual SNPs rs4588 and rs7041 were associated with both 25OHD concentration and 1,25 dihydroxyvitamin D concentrations; (b) higher PGS25OHD was associated with decreased concentrations of triglycerides and cholesterol, and reduced risks of vitamin D deficiency, disorders of lipid metabolism, and diabetes. In general, the findings for the African ancestry group were consistent with findings from the European ancestry analyses. Our study confirms the utility of PGS and two key variants within the GC gene (rs4588 and rs7041) to predict the risk of vitamin D deficiency in clinical settings and highlights the shared biology between vitamin D-related genetic pathways a range of health outcomes.

Vitamin D-binding protein deficiency: an underrecognized Mendelian disorder of vitamin D metabolism.

Vitamin D-binding protein (VDBP) deficiency is a recently discovered apparently benign biochemical disorder that can masquerade as treatment-resistant vitamin D deficiency and is likely underrecognized. We present the case of a child with persistently low 25OH vitamin D levels despite replacement therapy. Exome sequencing revealed a novel homozygous nonsense variant in the GC gene, leading to undetectable levels of VDBP. Interestingly, exome sequencing also revealed a homozygous loss-of-function variant in ZNF142, which likely explains the additional clinical features of recurrent febrile convulsions and global developmental delay. Our findings corroborate the two previously reported patients with autosomal recessive VDBP deficiency caused by biallelic GC variants and emphasize the importance of measuring VDBP levels in cases of apparent vitamin D deficiency that is treatment-resistant. We also urge caution in concluding "atypical" presentations without careful investigation of a potential dual molecular diagnosis.

The potential role of vitamin D binding protein in kidney disease: a comprehensive review.

Chronic kidney disease (CKD) is a growing health concern with a complex etiological landscape. Among the numerous factors implicated, vitamin D binding protein (VDBP) has emerged as a focal point of scientific studies because of its critical role in vitamin D metabolism and immune modulation. The relationship between VDBP and CKD reveals a complex web of molecular and biochemical details that have great potential for improving diagnostic understanding and treatment strategies for CKD. This review summarizes the multifaceted roles of VDBP, including its molecular dynamics, interactions with vitamin D, and subsequent implications for kidney function. The main focus of the discussion is how VDBP affects bone mineral homeostasis, highlighted by the dysregulation of calcium and phosphorus metabolism, which is a part of the pathophysiology of CKD. The discussion also touches on the immunomodulatory scope of VDBP and how it may reduce the chronic inflammatory environment that accompanies CKD. The diagnostic potential of VDBP as a biomarker for CKD has been rigorously examined, highlighting its capacity to improve early detection and prognostic assessment. Modification of VDBP activity has the potential to slow the course of CKD and improve patient outcomes. Furthermore, a detailed examination of the genetic polymorphisms of VDBP and their implications for CKD susceptibility and treatment responsiveness provides a perspective for personalized medical methods. Prospects for the future depend on the expansion of studies that try to understand the molecular mechanisms underlying the VDBP-CKD interaction, in addition to clinical trials that evaluate the effectiveness of VDBP-focused treatment approaches.

Association of vitamin D-binding protein polymorphisms and serum 25(OH)D concentration varies among Chinese healthy infants of different VDR-FokI genotypes: A multi-centre cross-sectional study.

Hypovitaminosis D during infancy is associated with the development of chronic diseases and poor health later in life. While the effect of environmental factors on vitamin D concentration has been extensively explored, this study aimed to explore the effect of genetic factors on vitamin D concentration among Chinese infants. We conducted a multi-centre cross-sectional study in Hong Kong from July 2019 to May 2021. A candidate genetic approach was adopted to study four selected genetic variants of the vitamin D-binding protein (DBP) and vitamin D receptor (VDR) (rs4588, rs7041, rs2282679 and rs2228570) to examine their associations with measured serum 25(OH)D concentration. A total of 378 Chinese infants aged 2-12 months were recruited in this study. Peripheral blood samples were collected from the infants to measure serum 25(OH)D concentration and extract DNA. Results showed that rs7041T and rs2282679C were significantly associated with lower serum 25(OH)D concentration. Further analysis of the DBP variants revealed that the GC1F allele was significantly associated with lower 25(OH)D concentration and identified as the risk DBP isoform in infants. While our results revealed that there is no direct association between VDR-FokI genotype and serum 25(OH)D concentration, a VDR-FokI genotype-specific pattern was observed in the association between DBP isoforms and serum 25(OH)D concentration. Specifically, significant associations were observed in the DBP genotypes GC1F/F, GC1F/2 and GC1S/2 among VDR-FokI TT/TC carriers, but not in VDR-FokI CC carriers. Our findings lay down the basis for the potential of genetic screening to identify high risk of hypovitaminosis D in Chinese infants.

Vitamin D receptor rs3782905 and vitamin D binding protein rs7041 polymorphisms are associated with hepatocellular carcinoma susceptibility in cirrhotic HCV patients.

BACKGROUND: The severity of chronic hepatitis C and susceptibility to hepatocellular carcinoma (HCC) are associated with genetic variations within vitamin D receptor (VDR) in several populations. This study aims to determine the significance of the VDRs (rs2228570, rs3782905, rs11568820) and DBP (rs7041) for the susceptibility to HCC in Egyptian patients with chronic HCV infection and their effect on the progression of liver cirrhosis to carcinogenesis. METHODS: Single nucleotide polymorphisms (SNPs) VDR (rs2228570, rs3782905), and DBP rs7041 were genotyped using restriction fragment length-PCR (RFLP-PCR) technique and VDR rs11568820 was genotyped using single strand polymorphism PCR (SSP PCR). These SNPs genotypes, haplotypes and linkage disequilibrium analyses were examined in 299 Egyptian individuals (100 HCV-cirrhotic patients, 99 HCC- HCV patients, and 100 healthy controls). RESULT: The VDR rs2228570 CC genotype, VDR rs3782905 GC and CC genotypes, and DBP rs7041 GG genotype are significantly higher in HCC. It is noteworthy that, VDR rs3782905 CC and DBP rs7041 TG genotypes are higher in HCV induced liver cirrhosis than with HCC progression in HCV infected patients. Furthermore, among patients, the relationship between these SNPs and smoking status, gender, and HCC susceptibility was reported. CONCLUSION: Among the four investigated SNPs, there are associations between VDR rs3782905 and DBP rs7041 and the HCC progression in Egyptian patients chronically infected with HCV. These SNPs are considered as risk factors in HCV induced liver cirrhosis and HCC. The combinations of these SNPs with smoking status and gender are statistically linked to a high risk of HCC. Future research with a larger sample size of subjects with HCV infection is advised, because chronic liver disease induced by HCV infection is the primary cause of HCC in Egypt. We recommend screening of these SNPs for prediction of LC and HCC development in HCV infected patients, which may improve the used therapeutic protocol. These results suggest that VDR polymorphisms may be potential determinants for HCC susceptibility in Egyptian HCV patients.

Genetic influence on urinary vitamin D binding protein excretion and serum levels: a focus on rs4588 C>A polymorphism in the GC gene.

Introduction: Vitamin D binding protein (VDBP) plays a crucial role in vitamin D transport and metabolism. The rs4588-A polymorphism of the GC gene, encoding VDBP, has been associated with altered serum VDBP and 25-hydroxyvitamin D (25OHD) levels. However, the mechanisms underlying these effects remain unclear. We aimed to investigate the relationship between urinary VDBP excretion and serum VDBP and 25OHD levels in individuals with and without the rs4588-A allele. Methods: A cross-sectional study was conducted on 109 children (mean age: 11.96 years) to explore the impact of rs4588-A on vitamin D metabolism and urinary VDBP excretion. Biochemical analyses determined serum 25OHD and VDBP levels, and urinary VDBP-to-creatinine ratio (u-VDBP/Cr). Genotyping for rs4588 SNP was performed using LightSNiP assay. Statistical analyses included correlation, linear regression, and comparison between allele groups. Results: Participants carrying the rs4588-A allele exhibited lower serum 25OHD levels compared to non-carriers (median (IQR): 11.85 (3.5) vs. 12.86 (4.9), p = 0.023). However, no statistically significant differences were observed in serum VDBP levels (126.34 ± 59.3 in rs4588-A vs. 136.49 ± 51.3 in non-rs4588-A, p = 0.141) or in u-VDBP/Cr (median (IQR): 0.4 (0.35) in rs4588-A vs. 0.386 (0.43) in non-rs4588-A, p = 0.189) between the two allele groups. A significant inverse correlation between u-VDBP/Cr and serum VDBP levels was found only in rs4588-A carriers (r = -0.367, p = 0.024). No such correlation was observed in non-carriers or the entire cohort. A linear regression analysis confirmed the impact of u-VDBP/Cr on serum VDBP levels in rs4588-A carriers (B = -0.269, t = -2.185, p = 0.035). Conclusion: Individuals with the rs4588-A allele in the GC gene had lower serum 25OHD levels. An inverse correlation between urinary VDBP excretion and serum VDBP levels was observed, suggesting a partial role of the renal pathway in altered serum VDBP and 25OHD levels linked to the rs4588-A allele.

Single nucleotide polymorphisms in vitamin D binding protein and 25-hydroxylase genes affect vitamin D levels in adolescents of Arab ethnicity in Kuwait.

Vitamin D deficiency (VDD) is widespread in the Arab world despite ample sunshine throughout the year. In our previous study, lifestyle and socio-demographic factors could explain only 45% of variability in vitamin D levels in Kuwaiti adolescents, suggesting that genetics might contribute to VDD in this region. Single nucleotide polymorphisms (SNP) in the 25-hydroxylase (CYP2R1) and the GC globulin (GC) genes have been reported to affect vitamin D levels in various ethnic groups in adults. In this study, we investigated the association of two SNPs from GC (rs4588 and rs7041) and three SNPs from CYP2R1 (rs10741657, rs11023374 and rs12794714) with vitamin D levels and VDD in a nationally representative sample of adolescents of Arab ethnicity from Kuwait. Multivariable linear regression, corrected for age, sex, parental education, governorate, body mass index, and exposure to sun, demonstrated that each of the 5 study variants showed significant associations with plasma 25(OH)D levels in one or more of the additive, recessive, and dominant genetic models - the rs10741657 under all the three models, rs12794714 under both the additive and recessive models, rs7041 under the recessive model; and rs4588 and rs11023374 under the dominant model. Minor alleles at rs4588 (T), rs7041 (A), rs11023374 (C), and rs12794714 (A) led to a decrease in plasma 25(OH)D levels - rs4588:[ß (95%CI) = -4.522 (-8.66,-0.38); p=0.033]; rs7041:[ß (95%CI) = -6.139 (-11.12,-1.15); p=0.016]; rs11023374:[ß (95%CI) = -4.296 (-8.18,-0.40); p=0.031]; and rs12794714:[ß (95%CI) = -3.498 (-6.27,-0.72); p=0.014]. Minor allele A at rs10741657 was associated with higher levels of plasma 25(OH)D levels [ß (95%CI) = 4.844 (1.62,8.06); p=0.003)] and lower odds of vitamin D deficiency (OR 0.40; p=0.002). These results suggest that the CYP2R1 and GC SNP variants are partly responsible for the high prevalence of VDD in Kuwait. Genotyping these variants may be considered for the prognosis of VDD in Kuwait.

Association between the genetic variant in the vitamin D pathway (rs2282679), circulating 25-hydroxyvitamin D levels, insulin resistance and metabolic syndrome criteria.

Introduction: Background and aims: some studies have reported links between 25-hydroxyvitamin D levels and the presence of metabolic syndrome. The aim of the present study was to evaluate whether an association exists among 25-hydroxyvitamin D, rs2282679 of the GC gene and metabolic syndrome (MS). Methods: the study involved a population of 134 postmenopausal obese females. Measurements of anthropometric parameters, blood pressure, bone turnover markers, fasting blood glucose, insulin resistance (HOMA-IR), lipid profile, C-reactive protein and prevalence of MS were recorded. Genotype of CG gene polymorphism (rs2282679) was evaluated. Results: insulin (delta: 4.6 ± 0.9 mUI/l; p = 0.02), triglycerides (delta: 21.6 ± 2.9 mg/dl; p = 0.04) and HOMA-IR (delta: 1.1 ± 0.9 unit; p = 0.02) were lower in TT subjects than TG + GG patients. The percentages of individuals who had MS (OR = 2.80, 95 % CI = 1.39-5.65; p = 0.02), hypertriglyceridemia (OR = 2.39, 95 % CI = 1.44-5.96; p = 0.01), and hyperglycemia (OR = 2.72, 95 % CI = 1.23-6.00; p = 0.43) were higher in G allele carriers. Logistic regression analysis showed an increased risk of MS in G allele carriers (OR = 2.36, 95 % CI = 1.11-5.91, p = 0.02) and an increased risk of 25-hydroxyvitamin D deficiency (< 20 ng/ml) (OR = 2.43, 95 % CI = 1.13-6.69, p = 0.02), too. Conclusions: a negative association among G allele and insulin resistance, hypertriglyceridemia, deficiency of 25 hydroxyvitamin D levels and MS was reported in this population.

Introducción: Antecedentes y objetivos: algunos estudios han demostrado una relación entre los niveles de 25-hidroxivitamina D y la presencia del síndrome metabólico. El objetivo de este estudio fue evaluar si existe una asociación entre la 25-hidroxivitamina D, la variante rs2282679 del gen GC y el síndrome metabólico (SM). Métodos: el estudio involucró a una población de 134 mujeres obesas posmenopáusicas. Se registraron parámetros antropométricos, presión arterial, marcadores de recambio óseo, glucemia en ayunas, resistencia a la insulina (HOMA-IR), perfil lipídico, proteína C reactiva y prevalencia de SM. Se evaluó el genotipo del polimorfismo del gen CG (rs2282679). Resultados: los niveles de insulina (delta: 4,6 ± 0,9 mUI/l; p = 0.02), triglicéridos (delta: 21,6 ± 2,9 mg/dl; p = 0,04) y HOMA-IR (delta: 1,1 ± 0,9 unidades; p = 0,02) fueron menores en los sujetos TT que en los pacientes TG + GG. Los porcentajes de individuos que tenían SM (OR = 2,80, IC 95 % = 1,39-5,65; p = 0,02), hipertrigliceridemia (OR = 2,39, IC 95 % = 1,44-5,96; p = 0,01) e hiperglucemia (OR = 2,72, IC 95 % = 1,23-6,00; p = 0,43) fueron mayores en los portadores del alelo G. El análisis de regresión logística mostró un mayor riesgo de SM en los portadores del alelo G (OR = 2,36, IC 95 % = 1,11-5,91; p = 0,02) y un mayor riesgo de deficiencia de 25-hidroxivitamina D (< 20 ng/ml) (OR = 2,43, IC 95 % = 1,13-6,69; p = 0,02). Conclusiones: en esta población hemos detectado una asociación negativa entre el alelo G y la resistencia a la insulina, hipertrigliceridemia, deficiencia niveles de 25-hidroxivitamina D y SM.

[Effect of vitamin D binding protein gene polymorphism on susceptibility and prognosis of severe acute pancreatitis].

OBJECTIVE: To investigate the effect of vitamin D binding protein (DBP) gene polymorphism on susceptibility and prognosis of severe acute pancreatitis (SAP). METHODS: A prospective study was conducted. Eighty-three patients with SAP who were admitted to the department of general surgery of Tianjin Fifth Central Hospital from March 2018 to March 2021 were selected as the research objects, and 83 healthy people in the same period were selected as controls. Peripheral blood RNA was extracted and reverse transcribed into cDNA, and the genotype and allele frequency of DBP gene rs7041 locus were detected by fluorescence quantitative analyzer. Hardy-Weinberg equilibrium was used to test the genetic balance. On the day of admission, serum C-reactive protein (CRP) level was detected by scattering immunoturbidimetry, serum procalcitonin (PCT) level was detected by electrochemiluminescence, serum DBP level was detected by enzyme-linked immunosorbent assay (ELISA), and neutrophil to lymphocyte ratio (NLR) was calculated automatically by the instrument. The length of intensive care unit (ICU) stay, the length of hospital stay and prognosis during hospitalization of patients were statistically analyzed. Multivariate Logistic regression analysis was used to screen the influencing factors of SAP occurrence. RESULTS: The results of Hardy-Weinberg equilibrium test showed that the distribution of gene polymorphisms in the two groups of subjects conformed to the law of genetic equilibrium. The frequencies of TT genotype and T allele of DBP gene rs7041 locus in the patients of SAP group were significantly higher than those in the healthy control group [TT genotype: 34.94% (29/83) vs. 9.64% (8/83), T allele: 55.42% (92/166) vs. 38.55% (64/166), both P < 0.01], and the frequency of GT genotype was significantly lower than that in the healthy control group [40.96% (34/83) vs. 57.83% (48/83), P < 0.05]. There was no significant difference in the frequency of GG genotype between the healthy control group and SAP group [32.53% (27/83) vs. 24.10% (20/83), P > 0.05]. Further multivariate Logistic regression analysis showed that TT genotype [odds ratio (OR) = 2.831, 95% confidence interval (95%CI) was 1.582-5.067, P < 0.001] and T allele (OR = 2.533, 95%CI was 1.435-4.472, P < 0.001) of DBP gene rs7041 locus were independent risk factors for SAP in healthy people, while GT genotype was a protective factor for SAP (OR = 0.353, 95%CI was 0.143-0.868, P = 0.041). The levels of CRP, PCT, NLR and DBP in patients with TT genotype of DBP gene rs7041 locus were significantly higher than those in patients with GG/GT genotype on the day of admission in SAP group [CRP (mg/L): 43.25±13.25 vs. 31.86±12.83, PCT (µg/L): 1.53±0.24 vs. 1.21±0.20, NLR: 3.15±0.53 vs. 2.71±0.48, DBP (µg/L): 87.78±19.64 vs. 70.58±18.67, all P < 0.01]. The length of ICU stay in patients with TT genotype of DBP gene rs7041 locus in SAP group was significantly longer than that in patients with GG/GT genotype (days: 11.35±1.58 vs. 9.71±1.35, P < 0.01). The length of hospital stay of patients with TT genotype was longer than that of patients with GG/GT genotype (days: 23.41±3.64 vs. 23.17±3.57), and the in-hospital mortality was higher than that of patients with GG/GT genotype [34.48% (10/29) vs. 29.63% (16/54)], but the difference was not statistically significant (both P > 0.05). CONCLUSIONS: The risk of SAP was significantly increased in patients with TT genotype of rs7041 locus of DBP gene, and the mechanism may be related to the increase of DBP expression. And carrying the TT genotype will prolong the ICU hospitalization time of SAP patients, but the effect on prognosis is not obvious.

Association of Single Nucleotide Polymorphism in VDR, GC Globulin and CYP2R1 with the Risk of Esophageal Cancer.

BACKGROUND: The proactive role of vitamin D has been well determined in different cancers. The protein that encodes the components of the vitamin D metabolism could appear to play a pivotal role in vitamin D stability and its maintenance. A polymorphism in vitamin-D-receptor (VDR), carrier globulin/binding protein (GC) and cytochrome P-450 family 2, subfamily R, polypeptide 1 (CYP2R1) genes has been predicted to be associated with the development of cancer. This study was designed to detect the association of VDR, GC Globulin and CYP2R1 gene polymorphism with the risk of esophageal cancer in the North-east Indian population. METHODS: To carry out the study, a total of 100 patients diagnosed with esophageal cancer and 101 healthy controls were enrolled. In a case-control manner, all samples were subjected to do genotype testing for known SNPs on the VDR (rs1544410), GC (rs4588), and CYP2R1 (rs10741657) genes using Restriction-fragment length polymorphism (RFLP) followed by Sanger sequencing. The collected demographic and clinical data were analysed using the statistical software package SPSS v22.0. RESULTS: The VDR haplotype heterozygous TC was found strongly associated with the carcinoma group (OR:1.09, 95%CI:0.67-1.75). The risk factors analysis using the GC globulin rs4588 phenotype, found a positive correlation in terms of mutant AA's harmful influence on the cancer cohort (OR = 1.125, OR=1.125, 95% CI, 0.573-2.206). The influence of the CYP2R1 rs10741657 polymorphism on the malignant cohort revealed that the GG mutant had a significant negative influence on the carcinoma, has an influential role in disease severity ( OR:1.736, at 95% CI; 0.368-8.180). CONCLUSION: In conclusion, this study revealed the potential association of VDR gene polymorphism in the progression and development of esophageal cancer in north east Indian population cohort.