A coding VKORC1 Asp36Tyr polymorphism predisposes to warfarin resistance

Blood ◽  
2006 ◽  
Vol 109 (6) ◽  
pp. 2477-2480 ◽  
Author(s):  
Ronen Loebstein ◽  
Ilana Dvoskin ◽  
Hillel Halkin ◽  
Manuela Vecsler ◽  
Aharon Lubetsky ◽  
...  

Abstract CYP2C9 and VKORC1 genetic variants are associated with low and intermediate warfarin dose requirements, but markers of high doses are less well characterized. We analyzed the VKORC1 coding sequence and known CYP2C9 and VKORC1 polymorphisms in 15 selected warfarin-resistant (dose, 80 to 185 mg/wk) and 8 warfarin-sensitive patients (7 to 13 mg/wk) and 99 unselected controls (8 to 105 mg/wk). We identified a coding VKORC1 Asp36Tyr polymorphism in 7 of 15 resistant compared with 0 of 8 sensitive patients (P = .026) Carriers of Asp36Tyr in the control group (8 of 99) required significantly higher warfarin doses of 80.9 ± 10.1 mg/wk compared with 42.7 ± 7.5 mg/wk in noncarriers (F = 9.79, P = .002). Asp36Tyr was significantly associated with doses of more than 70 mg/wk (odds ratio, 13.0; 95% confidence limit, 1.3 to 124.2), while doses of 20 to 70 mg/wk were associated with Asp36Tyr (partial r2 = .11; P = .004), CYP2C9*2 and *3 (r2 = .08; P = .01), and VKORC1*2 and *3 markers (r2 = .05; P = .05). All Asp36Tyr carriers also had VKORC1*1 tag–single nucleotide polymorphisms (tag-SNPs) indicating a new haplotype. Asp36Tyr was common in Jewish ethnic groups of Ethiopian (15%) and Ashkenazi (4%) origin. We suggest that Asp36Tyr is a new marker of the high end of the warfarin dosing range.

Blood ◽  
2010 ◽  
Vol 115 (18) ◽  
pp. 3827-3834 ◽  
Author(s):  
Nita A. Limdi ◽  
Mia Wadelius ◽  
Larisa Cavallari ◽  
Niclas Eriksson ◽  
Dana C. Crawford ◽  
...  

Abstract Warfarin-dosing algorithms incorporating CYP2C9 and VKORC1 −1639G>A improve dose prediction compared with algorithms based solely on clinical and demographic factors. However, these algorithms better capture dose variability among whites than Asians or blacks. Herein, we evaluate whether other VKORC1 polymorphisms and haplotypes explain additional variation in warfarin dose beyond that explained by VKORC1 −1639G>A among Asians (n = 1103), blacks (n = 670), and whites (n = 3113). Participants were recruited from 11 countries as part of the International Warfarin Pharmacogenetics Consortium effort. Evaluation of the effects of individual VKORC1 single nucleotide polymorphisms (SNPs) and haplotypes on warfarin dose used both univariate and multi variable linear regression. VKORC1 −1639G>A and 1173C>T individually explained the greatest variance in dose in all 3 racial groups. Incorporation of additional VKORC1 SNPs or haplotypes did not further improve dose prediction. VKORC1 explained greater variability in dose among whites than blacks and Asians. Differences in the percentage of variance in dose explained by VKORC1 across race were largely accounted for by the frequency of the −1639A (or 1173T) allele. Thus, clinicians should recognize that, although at a population level, the contribution of VKORC1 toward dose requirements is higher in whites than in nonwhites; genotype predicts similar dose requirements across racial groups.


2020 ◽  
Vol 41 (8) ◽  
pp. 1057-1064
Author(s):  
Yang Deng ◽  
Kunlin Xie ◽  
Christopher J Logothetis ◽  
Timothy C Thompson ◽  
Jeri Kim ◽  
...  

Abstract Background Epithelial–mesenchymal transition (EMT) plays a pivotal role in the progression of prostate cancer (PCa). However, little is known about genetic variants in the EMT pathway as predictors of aggressiveness, biochemical recurrence (BCR) and disease reclassification in localized PCa. Patients and methods In this multistage study, we evaluated 5186 single nucleotide polymorphisms (SNPs) from 264 genes related to EMT pathway to identify SNPs associated with PCa aggressiveness and BCR in the MD Anderson PCa (MDA-PCa) patient cohort (N = 1762), followed by assessment of the identified SNPs with disease reclassification in the active surveillance (AS) cohort (N = 392). Results In the MDA-PCa cohort, 312 SNPs were associated with high D’Amico risk (P < 0.05), among which, 14 SNPs in 10 genes were linked to BCR risk. In the AS cohort, 2 of 14 identified SNPs (rs76779889 and rs7083961) in C-terminal Binding Proteins 2 gene were associated with reclassification risk. The associations of rs76779889 with different endpoints were: D’Amico high versus low, odds ratio [95% confidence interval (CI)] = 2.89 (1.32–6.34), P = 0.008; BCR, hazard ratio (HR) (95% CI) = 2.88 (1.42–5.85), P = 0.003; and reclassification, HR (95% CI) = 2.83 (1.40–5.74), P = 0.004. For rs7083961, the corresponding risk estimates were: D’Amico high versus low, odds ratio (95% CI) = 1.69 (1.12–2.57), P = 0.013; BCR, HR (95% CI) = 1.87 (1.15–3.02), P = 0.011 and reclassification, HR (95% CI) = 1.72 (1.09–2.72), P = 0.020. There were cumulative effects of these two SNPs on modulating these endpoints. Conclusion Genetic variants in EMT pathway may influence the risks of localized PCa’s aggressiveness, BCR and disease reclassification, suggesting their potential role in the assessment and management of localized PCa.


2020 ◽  
Vol 41 (2) ◽  
pp. 134-140
Author(s):  
Yuriy Bisyuk ◽  
Andrew Dubovyi ◽  
Ilona DuBuske ◽  
Viktor Litus ◽  
Lawrence M. DuBuske

Background: This study assessed gene polymorphisms of the CD14 receptor (C-159T) and Toll-like receptor 4 (Asp299Gly) in a patient population in Crimea, Ukraine, stratified by clinical (early versus late onset; frequent versus occasional relapses; fixed versus reversible obstruction) and immunologic (atopic versus nonatopic; eosinophilic; neutrophilic or paucigranulocytic inflammation) subtype. Methods: Two polymorphisms, CD14 C-159T and TLR4 Asp299Gly, were assessed in 331 patients with asthma. The control group included 285 volunteers who were nonatopic. The single nucleotide polymorphisms were studied by using polymerase chain reaction with electrophoretic detection. Results: There were increased odds of asthma development in patients with the Asp299Gly TLR4 mutation compared with the general population underdominant odds ratio (OR) 1.52 [95% confidence interval (CI), 1.00‐2.32] and overdominant (OR 1.55 [95% CI, 1.01‐2.38]) models after adjustment for gender and age. In addition, mutations in this gene decreased the odds of nonatopic asthma in underdominant (OR 0.26 [95% CI, 0.07‐0.93]; p = 0.027), overdominant (OR 0.27 [95% CI, 0.07‐0.96]; p = 0.033), and log-additive models (OR 0.26 [95% CI, 0.07‐0.93]; p = 0.026) compared with the atopic subgroup after adjustment for gender, age, number of exacerbations, and type of airway inflammation. Allele frequencies for CD14 and TLR4 polymorphisms did not show statistical differences between the patients with asthma and the control subjects. Conclusion: CD14 C-159T polymorphisms were not associated with asthma in the adult population in Crimea. TLR4 Asp299Gly polymorphisms were associated with asthma and with decreased odds of nonatopic asthma compared with atopic asthma in the adult population in Crimea.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sabrina Samad Shoily ◽  
Tamim Ahsan ◽  
Kaniz Fatema ◽  
Abu Ashfaqur Sajib

AbstractDiabetes mellitus is a complex and heterogeneous metabolic disorder which is often pre- or post-existent with complications such as cardiovascular disease, hypertension, inflammation, chronic kidney disease, diabetic retino- and nephropathies. However, the frequencies of these co-morbidities vary among individuals and across populations. It is, therefore, not unlikely that certain genetic variants might commonly contribute to these conditions. Here, we identified four single nucleotide polymorphisms (rs5186, rs1800795, rs1799983 and rs1800629 in AGTR1, IL6, NOS3 and TNFA genes, respectively) to be commonly associated with each of these conditions. We explored their possible interplay in diabetes and associated complications. The variant allele and haplotype frequencies at these polymorphic loci vary among different super-populations (African, European, admixed Americans, South and East Asians). The variant alleles are particularly highly prevalent in different European and admixed American populations. Differential distribution of these variants in different ethnic groups suggests that certain drugs might be more effective in selective populations rather than all. Therefore, population specific genetic architectures should be considered before considering a drug for these conditions.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Youguo Hao ◽  
Lijun Xie ◽  
Jing Xia ◽  
Zhen Liu ◽  
Baoxiu Yang ◽  
...  

Abstract Background Rheumatoid Arthritis (RA) is a chronic inflammatory condition characterized by autoantibodies development and an elevated spectrum of pro-inflammatory cytokines. Previous reports highlighted a relationship between IL-21and the pathogenesis of RA. Although elevated IL-21 levels have been reported in RA patients, the association of common IL-21 genetic variants with a predisposition to RA development in the Chinese population lacks. Materials and methods Five hundred and fourteen Chinese subjects (healthy controls: 303 and rheumatoid arthritis patients: 211) were enrolled in the study. Clinical data of patients were collected from medical records, and patients were treated as per the guidelines. Common single nucleotide polymorphisms in the IL-21 gene (rs907715, rs2221903, rs2055979 and rs6822844) were genotyped by TaqMan SNPs genotyping method. IL-21 level in plasma of RA patients and healthy subjects was measured by ELISA. Results The plasma level of IL-21 was significantly higher in subjects with rheumatoid arthritis relative to healthy controls (p < 0.0001). A positive correlation was observed between IL-21 level and DAS28 score, indicating the association of the cytokine with the worsening of the disease (Spearman r = 0.61, p < 0.0001). The prevalence of AA genotype (rs2055979) was significantly higher in RA subjects than in the controls (p < 0.0001, χ2 = 34.73, OR = 4.34, 95% CI = 2.623 to 7.219). Furthermore, elevated plasma IL-21 was observed in the rs2055979-AA genotype compared to CC type (p < 0.0001). Conclusion IL-21 plays a crucial function in rheumatoid arthritis pathogenesis. IL-21 rs2055979 polymorphism is associated with IL-21 plasma levels and is predisposed to RA development in the Chinese population.


2020 ◽  
Vol 10 (1) ◽  
pp. 2 ◽  
Author(s):  
Laith N. AL-Eitan ◽  
Doaa M. Rababa’h ◽  
Nancy M. Hakooz ◽  
Mansour A. Alghamdi ◽  
Rana B. Dajani

Several genetic variants have been identified that cause variation among different populations and even within individuals of a similar descent. This leads to interindividual variations in the optimal dose of the drug that is required to sustain the treatment efficiency. In this study, 56 single nucleotide polymorphisms (SNPs) within several pharmacogenes were analyzed in 128 unrelated subjects from a genetically isolated group of Circassian people living in Jordan. We also compared these variant distributions to other ethnic groups that are available at two databases (Genome 1000 and eXAC). Our results revealed that the distribution of allele frequencies within genes among Circassians in Jordan showed similarities and disparities when compared to other populations. This study provides a powerful base for clinically relevant SNPs to enhance medical research and future pharmacogenomic studies. Rare variants detected in isolated populations can significantly guide to novel loci involved in the development of clinically relevant traits.


Cephalalgia ◽  
2016 ◽  
Vol 36 (11) ◽  
pp. 1028-1037 ◽  
Author(s):  
Jong-Ling Fuh ◽  
Ming-Yi Chung ◽  
Shu-Chih Yao ◽  
Ping-Kun Chen ◽  
Yi-Chu Liao ◽  
...  

Objective Several genetic variants have been found to increase the risk of restless legs syndrome (RLS). The aim of the present study was to determine if these genetic variants were also associated with the comorbidity of RLS and migraine in patients. Methods Thirteen single-nucleotide polymorphisms (SNPs) at six RLS risk loci ( MEIS1, BTBD9, MAP2K5, PTPRD, TOX3, and an intergenic region on chromosome 2p14) were genotyped in 211 migraine patients with RLS and 781 migraine patients without RLS. Association analyses were performed for the overall cohort, as well as for the subgroups of patients who experienced migraines with and without aura and episodic migraines (EMs) vs. chronic migraines (CMs). In order to verify which genetic markers were potentially related to the incidence of RLS in migraine patients, multivariate regression analyses were also performed. Results Among the six tested loci, only MEIS1 was significantly associated with RLS. The most significant SNP of MEIS1, rs2300478, increased the risk of RLS by 1.42-fold in the overall cohort ( p = 0.0047). In the subgroup analyses, MEIS1 augmented the risk of RLS only in the patients who experienced EMs (odds ratio (OR) = 1.99, p = 0.0004) and not those experiencing CMs. Multivariate regression analyses further showed that rs2300478 in MEIS1 (OR = 1.39, p = 0.018), a CM diagnosis (OR = 1.52, p = 0.022), and depression (OR = 1.86, p = 0.005) were independent predictors of RLS in migraine. Conclusions MEIS1 variants were associated with an increased risk of RLS in migraine patients. It is possible that an imbalance in iron homeostasis and the dopaminergic system may represent a link between RLS incidence and migraines.


Author(s):  
Harini Venkata Subbiah ◽  
Usha Subbiah ◽  
Athira Ajith

Dental caries is a multifactorial disease that affects a large proportion of the population with both genetic and environmental factors contributing to the disease. Even in healthy oral environmental conditions, some individuals are susceptible to dental caries due to potential genetic contribution. Antimicrobial peptides are expressed in oral cavity and play an important role against microbial colonization and form an important first line defense against cariogenic bacteria. In the present study, we attempt to identify genetic variants that would cause significant functional impact towards susceptibility to dental caries. We investigated single nucleotide polymorphisms (SNPs) of beta-defensin 1 (DEFB1) as predictors of dental caries in tamil ethnic population. A total of 120 subjects were recruited for this study, which included 60 dental caries patients (DMFT>5) and 60 healthy controls (DMFT=0). Three SNPs of 5’UTR regulatory elements of DEFB1 were genotyped by PCR followed by Sanger sequencing. The genotypes associated with susceptibility to caries were found to be significant between rs11362 (p=.025, odds ratio = 3.72, 95% confidence interval (CI) = 1.289-10.742), rs1799946 (p=.023, odds ratio=4.32, 95% CI = 1.33-14.028) gene polymorphisms and risk of dental caries (DMFT>5) in tamil ethnicity. The variant genotype GG of rs1800972 polymorphism was found to be high in cases than controls but was not significant (p=0.136). Our data suggested that β-defensin 1 polymorphisms play a role in the susceptibility to dental caries.


Genes ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 578 ◽  
Author(s):  
Laith AL-Eitan ◽  
Ayah Almasri ◽  
Rame Khasawneh

Warfarin is an oral anticoagulant frequently used in the treatment of different cardiovascular diseases. Genetic polymorphisms in the CYP2C9 and VKORC1 genes have produced variants with altered catalytic properties. A total of 212 cardiovascular patients were genotyped for 17 Single Nucleotide Polymorphisms (SNPs) within the CYP2C9 and VKORC1 genes. This study confirmed a genetic association of the CYP2C9*3 and VKORC1 rs10871454, rs8050894, rs9934438, and rs17708472 SNPs with warfarin sensitivity. This study also found an association between CYP2C9 and VKORC1 genetic haplotype blocks and warfarin sensitivity. The initial warfarin dose was significantly related to the CYP2C9*3 polymorphism and the four VKORC1 SNPs (p < 0.001). There were significant associations between rs4086116 SNP and TAT haplotype within CYP2C9 gene and rs17708472 SNP and CCGG haplotype within VKORC1 gene and warfarin responsiveness. However, possessing a VKORC1 variant allele was found to affect the international normalized ratio (INR) outcomes during initiation of warfarin therapy. In contrast, there was a loose association between the CYP2C9 variant and INR measurements. These findings can enhance the current understanding of the great variability in response to warfarin treatment in Arabs.


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