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Holail J, Mobarak R, Al-Ghamdi B, Aljada A, Fakhoury H. Association of VKORC1 and CYP2C9 single-nucleotide polymorphisms with warfarin dose adjustment in Saudi patients. Drug Metab Pers Ther 2022; 37:353-359. [PMID: 36476275 DOI: 10.1515/dmpt-2022-0108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 02/14/2022] [Indexed: 12/13/2022]
Abstract
OBJECTIVES Despite its wide usage, warfarin therapy remains challenging due to its narrow therapeutic index, inter-individual response variability, and risk of bleeding. Previous reports have suggested that polymorphisms in VKORC1 and CYP2C9 genes could influence warfarin therapy. Herein, we investigated whether VKORC1 -1173C>T, CYP2C9*2, and CYP2C9*3 gene polymorphisms are associated with warfarin dose adjustment and related bleeding events. METHODS This cross-sectional study was conducted on Saudi adults receiving warfarin for more than 1 month. Their demographics and relevant clinical data were obtained. Genotyping for VKORC1 -1173C>T, CYP2C9*2, and CYP2C9*2 genotypes was performed. RESULTS Patients who are homozygous for the mutant T allele VKORC1 T/T required the lowest warfarin daily maintenance dose, compared to VKORC1 C/T and VKORC1 C/C. Similarly, there was a significant reduction in warfarin daily maintenance dose among CYP2C9*1/*3 and CYP2C9*1/*2 groups compared to CYP2C9*1/*1. However, we found no significant correlation between the studied polymorphisms and warfarin-associated bleeding. CONCLUSIONS Similar to other populations, the VKORC1 and CYP2C9 gene polymorphisms are significantly associated with warfarin dosage in Saudi patients. The presence of at least one copy of the mutant alleles for VKORC1 -1173C>T, CYP2C9*2, and CYP2C9*3 is associated with a significant reduction in warfarin maintenance dose.
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Affiliation(s)
- Jasmine Holail
- Department of Biochemistry and Molecular Medicine, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Reem Mobarak
- Department of Biochemistry and Molecular Medicine, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Bandar Al-Ghamdi
- Heart Center, King Faisal Specialist Hospital and Research Center (KFSH&RC), Riyadh, Saudi Arabia
| | - Ahmad Aljada
- Department of Biochemistry and Molecular Medicine, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Hana Fakhoury
- Department of Biochemistry and Molecular Medicine, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
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Asiimwe IG, Pirmohamed M. Ethnic Diversity and Warfarin Pharmacogenomics. Front Pharmacol 2022; 13:866058. [PMID: 35444556 PMCID: PMC9014219 DOI: 10.3389/fphar.2022.866058] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Accepted: 03/14/2022] [Indexed: 12/23/2022] Open
Abstract
Warfarin has remained the most commonly prescribed vitamin K oral anticoagulant worldwide since its approval in 1954. Dosing challenges including having a narrow therapeutic window and a wide interpatient variability in dosing requirements have contributed to making it the most studied drug in terms of genotype-phenotype relationships. However, most of these studies have been conducted in Whites or Asians which means the current pharmacogenomics evidence-base does not reflect ethnic diversity. Due to differences in minor allele frequencies of key genetic variants, studies conducted in Whites/Asians may not be applicable to underrepresented populations such as Blacks, Hispanics/Latinos, American Indians/Alaska Natives and Native Hawaiians/other Pacific Islanders. This may exacerbate health inequalities when Whites/Asians have better anticoagulation profiles due to the existence of validated pharmacogenomic dosing algorithms which fail to perform similarly in the underrepresented populations. To examine the extent to which individual races/ethnicities are represented in the existing body of pharmacogenomic evidence, we review evidence pertaining to published pharmacogenomic dosing algorithms, including clinical utility studies, cost-effectiveness studies and clinical implementation guidelines that have been published in the warfarin field.
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Affiliation(s)
- Innocent G Asiimwe
- The Wolfson Centre for Personalized Medicine, MRC Centre for Drug Safety Science, Department of Pharmacology and Therapeutics, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Munir Pirmohamed
- The Wolfson Centre for Personalized Medicine, MRC Centre for Drug Safety Science, Department of Pharmacology and Therapeutics, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, United Kingdom
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Holail J, Mobarak R, Al-Ghamdi B, Aljada A, Fakhoury H. Association of VKORC1 and CYP2C9 single-nucleotide polymorphisms with warfarin dose adjustment in Saudi patients. Drug Metab Pers Ther 2022; 0:dmdi-2022-0108. [PMID: 35365981 DOI: 10.1515/dmdi-2022-0108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 02/14/2022] [Indexed: 11/15/2022]
Abstract
OBJECTIVES Despite its wide usage, warfarin therapy remains challenging due to its narrow therapeutic index, inter-individual response variability, and risk of bleeding. Previous reports have suggested that polymorphisms in VKORC1 and CYP2C9 genes could influence warfarin therapy. Herein, we investigated whether VKORC1 -1173C>T, CYP2C9*2, and CYP2C9*3 gene polymorphisms are associated with warfarin dose adjustment and related bleeding events. METHODS This cross-sectional study was conducted on Saudi adults receiving warfarin for more than 1 month. Their demographics and relevant clinical data were obtained. Genotyping for VKORC1 -1173C>T, CYP2C9*2, and CYP2C9*2 genotypes was performed. RESULTS Patients who are homozygous for the mutant T allele VKORC1 T/T required the lowest warfarin daily maintenance dose, compared to VKORC1 C/T and VKORC1 C/C. Similarly, there was a significant reduction in warfarin daily maintenance dose among CYP2C9*1/*3 and CYP2C9*1/*2 groups compared to CYP2C9*1/*1. However, we found no significant correlation between the studied polymorphisms and warfarin-associated bleeding. CONCLUSIONS Similar to other populations, the VKORC1 and CYP2C9 gene polymorphisms are significantly associated with warfarin dosage in Saudi patients. The presence of at least one copy of the mutant alleles for VKORC1 -1173C>T, CYP2C9*2, and CYP2C9*3 is associated with a significant reduction in warfarin maintenance dose.
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Affiliation(s)
- Jasmine Holail
- Department of Biochemistry and Molecular Medicine, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Reem Mobarak
- Department of Biochemistry and Molecular Medicine, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Bandar Al-Ghamdi
- Heart Center, King Faisal Specialist Hospital and Research Center (KFSH&RC), Riyadh, Saudi Arabia
| | - Ahmad Aljada
- Department of Biochemistry and Molecular Medicine, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Hana Fakhoury
- Department of Biochemistry and Molecular Medicine, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
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Naushad SM, Kutala VK, Hussain T, Alrokayan SA. Pharmacogenetic determinants of warfarin in the Indian population. Pharmacol Rep 2021; 73:1396-1404. [PMID: 34106453 DOI: 10.1007/s43440-021-00297-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Revised: 06/01/2021] [Accepted: 06/03/2021] [Indexed: 01/13/2023]
Abstract
BACKGROUND Several studies optimized the warfarin dose based on CYP2C9*2, CYP2C9*3, VKORC1 -1639 G > A, CYP4F2 V433M. But, the information on the rare variants is lacking. In this study, we have explored the prevalence of common and rare pharmacogenetic determinants of warfarin and determined their damaging nature. METHODS We have analyzed 2000 healthy adults using the Infinium global screening array (GSA) for 15 pharmacogenetic determinants of warfarin. In addition, we have elucidated the impact of these variants on protein function, stability, dynamics, evolutionary preservation, and ligand binding propensity. RESULTS The GSA Analysis has revealed that CYP4F2 V433M (MAF: 39.425%), VKORC1 -1639 G > A (MAF: 20.5%), CYP2C9*3 (MAF:9.925%), and CYP2C9*2 (MAF:4.575%) are common, while CYP2C9*14 (MAF: 1.475%), CYP2C9*4 (0.175%), CYP2C9*5 (0.125%), and CYP2C9*11 (0.125%) are rare. Position-specific evolutionary preservation (PSEP) analysis has revealed that CYP2C9*4 is possibly damaging, while CYP2C9*5, CYP2C9*11, and CYP2C9*14 are probably damaging. CYP2C9*4 has high thermolability (-10.14 kcal/mol). Among the rare CYP2C9 variants, CYP2C9*4 and CYP2C9*11 exert destabilizing effects and may have increased molecular flexibility, while CYP2C9*5 and CYP2C9*14 exert stabilizing effects and may have decreased molecular flexibility. DNase I footprint analysis has revealed the loss of the E-box consensus sequence due to VKORC1 -1639 G > A polymorphism. CONCLUSION CYP2C9*2, CYP2C9*3, VKORC1 -1639 G > A and CYP4F2 V433M are common; CYP2C9*4, CYP2C9*5, CYP2C9*11, and CYP2C9*14 variants are rare in Indian subjects. All the CYP2C9 variants are found to be damaging. DNase I footprint analysis provided the mechanistic rationale for the association of VKORC1 -1639 G > A with warfarin sensitivity.
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Affiliation(s)
- Shaik Mohammad Naushad
- Department of Biochemical Genetics and Pharmacogenomics, Sandor Speciality Diagnostics Pvt Ltd, Banjara Hills, Road No 3, Hyderabad, 500034, India.
| | - Vijay Kumar Kutala
- Department of Clinical Pharmacology and Therapeutics, Nizam's Institute of Medical Sciences, Hyderabad, India
| | - Tajamul Hussain
- Center of Excellence in Biotechnology Research, College of Science, King Saud University, Riyadh, 11451, Saudi Arabia
- Research Chair for Biomedical Applications of Nanomaterials, Biochemistry Department, College of Science, King Saud University, Riyadh, 11451, Saudi Arabia
| | - Salman A Alrokayan
- Research Chair for Biomedical Applications of Nanomaterials, Biochemistry Department, College of Science, King Saud University, Riyadh, 11451, Saudi Arabia
- Biochemistry Department, College of Science, King Saud University, Riyadh, 11451, Saudi Arabia
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Al Ammari M, AlBalwi M, Sultana K, Alabdulkareem IB, Almuzzaini B, Almakhlafi NS, Aldrees M, Alghamdi J. The effect of the VKORC1 promoter variant on warfarin responsiveness in the Saudi WArfarin Pharmacogenetic (SWAP) cohort. Sci Rep 2020; 10:11613. [PMID: 32669629 PMCID: PMC7363835 DOI: 10.1038/s41598-020-68519-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 06/25/2020] [Indexed: 11/09/2022] Open
Abstract
Warfarin is a frequently prescribed oral anticoagulant with a narrow therapeutic index, requiring careful dosing and monitoring. However, patients respond with significant inter-individual variability in terms of the dose and responsiveness of warfarin, attributed to genetic polymorphisms within the genes responsible for the pharmacokinetics and pharmacodynamics of warfarin. Extensive warfarin pharmacogenetic studies have been conducted, including studies resulting in genotype-guided dosing guidelines, but few large scale studies have been conducted with the Saudi population. In this study, we report the study design and baseline characteristics of the Saudi WArfarin Pharmacogenomics (SWAP) cohort, as well as the association of the VKORC1 promoter variants with the warfarin dose and the time to a stable INR. In the 936 Saudi patients recruited in the SWAP study, the minor allele C of rs9923231 was significantly associated with a 8.45 mg higher weekly warfarin dose (p value = 4.0 × 10-46), as well as with a significant delay in achieving a stable INR level. The addition of the rs9923231 status to the model, containing all the significant clinical variables, doubled the warfarin dose explained variance to 31%. The SWAP cohort represents a valuable resource for future research with the objective of identifying rare and prevalent genetic variants, which can be incorporated in personalized anticoagulation therapy for the Saudi population.
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Affiliation(s)
- Maha Al Ammari
- Pharmaceutical Care Services, King Abdulaziz Medical City, Ministry of National Guard Health Affairs, King Abdullah International Medical Research Center, King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Mohammed AlBalwi
- Department of Pathology and Laboratory, King Abdullah International Medical Research Center, King Saud Bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia
| | - Khizra Sultana
- Research Office, King Abdullah International Medical Research Center, King Saud Bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia
| | - Ibrahim B Alabdulkareem
- Health Sciences Research Center, King Abdullah Bin Abdulaziz University Hospital, Princess Nourah Bint Abdulrahman University, Riyadh, Saudi Arabia
| | - Bader Almuzzaini
- Medical Genomics Research Department, King Abdullah International Medical Research Center, Ministry of National Guard Health Affairs, King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Nada S Almakhlafi
- Pharmaceutical Care Services, King Abdulaziz Medical City, Ministry of National Guard Health Affairs, King Abdullah International Medical Research Center, King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Mohammed Aldrees
- Medical Genomics Research Department, King Abdullah International Medical Research Center, Ministry of National Guard Health Affairs, King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Jahad Alghamdi
- King Abdullah International Medical Research Center, The Saudi Biobank, King Saud Bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs, Riyadh, Saudi Arabia.
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Akdeniz CS, Cevik M, Canbolat IP, Yurdakul S, Cagatay P, Ciftci C, Karaalp A, Susleyici B. The effects of CYP2C9 and VKORC1 gene polymorphisms on warfarin maintenance dose in Turkish cardiac patients. Future Cardiol 2020; 16:645-654. [PMID: 32583677 DOI: 10.2217/fca-2020-0027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Aim: Our aim was to examine the effect of CYP2C9 and VKORC1 polymorphisms on warfarin dose requirements in Turkish patients. Materials & methods: 24 warfarin prescribed patients were included and analyzed for eight VKORC1 and 6 CYP2C9 polymorphisms in the study. Results: Patients with CYP2C9 *1/*1 and VKORC1 -1639 GG and GA genotypes required higher warfarin doses in comparison to wild type VKORC1 genotype. Patients with CYP2C9 *1/*3 and VKORC1 -1639 GG genotypes simultaneously, required the lowest dose of warfarin (4.64 mg/day). Patients with CYP2C9 *1/*1 and VKORC1 9041 AA genotype were found to require higher warfarin doses. Conclusion: Our results provide additional evidence to support the hypothesis that CYP2C9 *2, *3, VKORC1 9041 G > A polymorphisms explain considerable proportion of inter-individual variability in warfarin dose requirement.
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Affiliation(s)
- Cansu Selcan Akdeniz
- Department of Cardiology, Demiroglu Bilim University Faculty of Medicine, Istanbul, Turkey
| | - Mehtap Cevik
- Department of Molecular Biology, Marmara University Faculty of Science & Letters, Istanbul, Turkey
| | - Ismail Polat Canbolat
- Department of Cardiology, Demiroglu Bilim University Faculty of Medicine, Istanbul, Turkey
| | - Selen Yurdakul
- Department of Cardiology, Demiroglu Bilim University Faculty of Medicine, Istanbul, Turkey
| | - Penbe Cagatay
- Vocational School of Health Service, Department of Medical Services & Technics, Istanbul University - Cerrahpasa, Istanbul, Turkey
| | - Cavlan Ciftci
- Department of Cardiology, Demiroglu Bilim University Faculty of Medicine, Istanbul, Turkey
| | - Atila Karaalp
- Department of Medical Pharmacology, Marmara University School of Medicine, Istanbul, Turkey
| | - Belgin Susleyici
- Department of Molecular Biology, Marmara University Faculty of Science & Letters, Istanbul, Turkey
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Bader L, Mahfouz A, Kasem M, Mohammed S, Alsaadi S, Abdelsamad O, Elenani R, Soaly E, Elzouki A, Rizk N, Khalifa S, Shahin MH, Cavallari LH, Mraiche F, Elewa H. The effect of genetic and nongenetic factors on warfarin dose variability in Qatari population. THE PHARMACOGENOMICS JOURNAL 2019; 20:277-284. [PMID: 31653973 DOI: 10.1038/s41397-019-0116-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2019] [Revised: 10/10/2019] [Accepted: 10/14/2019] [Indexed: 02/06/2023]
Abstract
The objective of this study is to estimate the prevalence of VKORC1, CYP2C9, and CYP4F2 genetic variants and their contribution to warfarin dose variability in Qataris. One hundred and fifty warfarin-treated Qatari patients on a stable dose and with a therapeutic INR for at least three consecutive clinic visits were recruited. Saliva samples were collected using Oragene DNA self-collection kit, followed by DNA purification and genotyping via TaqMan Real-Time-PCR assay. The population was stratified into derivation and validation cohorts for the dosing model. The minor allele frequency (MAF) of VKORC1 (-1639G>A) was A (0.47), while the MAF's for the CYP2C9*2 and *3 and CYP4F2*3 were T (0.12), C (0.04) and T (0.43), respectively. Carriers of at least one CYP2C9 decreased function allele (*2 or *3) required lower median (IQR) warfarin doses compared to noncarriers [24.5 (14.5) mg/week vs. 35 (21) mg/week, p < 0.001]. Similarly, carriers of each additional copy of (A) variant in VKORC1 (-1639G>A) led to reduction in warfarin dose requirement compared to noncarriers [21(7.5) vs. 31.5(18.7) vs. 43.7(15), p < 0.0001]. CYP4F2*3 polymorphism on the other hand was not associated with warfarin dose. Multivariate analysis on the derivation cohort (n = 104) showed that a dosing model consisting of hypertension (HTN), heart failure (HF), VKORC1 (-1639G>A), CYP2C9*2 & *3, and smoking could explain 39.2% of warfarin dose variability in Qataris (P < 0.001). In the validation cohort (n = 45), correlation between predicted and actual warfarin doses was moderate (Spearman's rho correlation coefficient = 0.711, p < 0.001). This study concluded that VKORC1 (-1639G>A), CYP2C9*2 & *3 are the most significant predictors of warfarin dose along with HTN, HF and smoking.
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Kocael A, Eronat AP, Tüzüner MB, Ekmekçi A, Orhan AL, İkizceli İ, Yılmaz-Aydoğan H, Öztürk O. Interpretation of the effect of CYP2C9, VKORC1 and CYP4F2 variants on warfarin dosing adjustment in Turkey. Mol Biol Rep 2019; 46:1825-1833. [PMID: 30712247 DOI: 10.1007/s11033-019-04634-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 01/22/2019] [Indexed: 01/09/2023]
Abstract
It was aimed to underline the importance and explain the meaning of genetic testing in warfarin dosing and investigate and evaluate the contributions of the CYP2C9, VKORC1, and CYP4F2 variants in a Turkish population. Two hundred patients were genotyped for CYP2C9 (rs1799853, rs1057910 and rs56165452), VKORC1 (rs9934438, rs8050894, rs9923231, rs7294 and rs2359612) and CYP4F2 (rs2108622), yet, only 127 patients were found suitable for further evaluation in terms of their personal response to warfarin due to long term usage and available INR and dose usage information. The DNA sequences were determined by the ABI PRISM 3100 Genetic Analyzer to 3130xl System (Applied Biosystems, Foster City, California). Warfarin dose application suggestions by warfaringdosing.org, FDA and MayoClinic were followed. Dose requirements in the Turkish population were found higher than the suggested doses by warfarindosing.org. The multivariate logistic regression analysis reveals the utilization of VCORC1 genetic evaluation is valuable in warfarin dosing (low and moderate vs. high) in this study (p < 0.001). The present study provides findings for clinicians to adapt the genetic data to the daily practice. We observed that the VKORC1 variant showed a more potent impact in warfarin dosing in this study.
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Affiliation(s)
- Ahmet Kocael
- Department of General Surgery, Cerrahpasa Medical Faculty, Istanbul University, Istanbul, Turkey
| | - Allison Pınar Eronat
- Department of Molecular Medicine, Aziz Sancar Institute of Experimental Medicine, Istanbul University, Istanbul, Turkey
| | - Mete Bora Tüzüner
- Research and Development Center, Acibadem Labmed Clinical Laboratories, Istanbul, Turkey
| | - Ahmet Ekmekçi
- Clinic of Cardiology, Dr Siyami Ersek Thoracic and Cardiovascular Surgery Center Training and Research Hospital, Istanbul, Turkey
| | - Ahmet Lütfullah Orhan
- Clinic of Cardiology, Dr Siyami Ersek Thoracic and Cardiovascular Surgery Center Training and Research Hospital, Istanbul, Turkey
| | - İbrahim İkizceli
- Department of General Surgery, Cerrahpasa Medical Faculty, Istanbul University, Istanbul, Turkey
| | - Hülya Yılmaz-Aydoğan
- Department of Molecular Medicine, Aziz Sancar Institute of Experimental Medicine, Istanbul University, Istanbul, Turkey
| | - Oğuz Öztürk
- Department of Molecular Medicine, Aziz Sancar Institute of Experimental Medicine, Istanbul University, Istanbul, Turkey.
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Frequency of vitamin K oxidoreductase complex subunit-1 (VKORC1) polymorphisms and warfarin dose management in patients with venous thromboembolism. THE PHARMACOGENOMICS JOURNAL 2018; 18:646-651. [DOI: 10.1038/s41397-018-0037-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2017] [Revised: 04/14/2018] [Accepted: 06/19/2018] [Indexed: 12/25/2022]
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Kumar S, Dubey AK, Kalita J, Misra UK. The Role of Clinical Variables and VKORC1 Polymorphism in Efficacy and Stability of Acenocoumarol in Neurological Patients. J Neurosci Rural Pract 2018; 9:186-192. [PMID: 29725167 PMCID: PMC5912022 DOI: 10.4103/jnrp.jnrp_306_17] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Objective: To analyze the clinical importance of VKORC1 polymorphism and its correlation with stability of oral anticoagulation. Patients and Methods: In a hospital-based study, the patients on oral anticoagulant (OAC) were included during 2013–2016. The patients received OAC for cardioembolic stroke, cerebral venous sinus thrombosis (CVST), and prevention of deep vein thrombosis (DVT). Demographic, clinical, and neurological findings were recorded. Stability of anticoagulation was determined by percentage of time international normalized ratio (INR) values were in therapeutic range. Time in therapeutic range (TTR) >65% was defined as stable and <65% was defined unstable. VKORC 1 polymorphism was studied by polymerase chain reaction and correlated with daily dose of OAC and stability of INR. Results: A total of 157 patients with a median age of 40 years were included in the study. Ninety-two patients received OAC for secondary stroke prevention, 62 for CVST, and 3 for DVT. Out of 2976 INR reports, 1458 (49%) were in the therapeutic range, 997 (33.1%) were below the therapeutic range, and 521 (17.5%) were above the therapeutic level. Stable INR was obtained in 75 (47.77%) patients which was improved by drug modification in 3 and dietary adjustment in 12 patients. VKORC1 polymorphism revealed GG genotype in 127 (80.9%), GA genotype in 22 (14%), and AA genotype in 8 (5.1%) patients. Therapeutic range of INR was seen in 49%, below therapeutic range was seen in 31.5%, and above in 17.5%. Conclusion: VKORC1 polymorphism was related to mean daily dose of OAC but not to the stability of INR.
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Affiliation(s)
- Surendra Kumar
- Department of Neurology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India
| | - Ashish Kant Dubey
- Department of Neurology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India
| | - Jayantee Kalita
- Department of Neurology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India
| | - Usha Kant Misra
- Department of Neurology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India
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Pharmacogenetics-Based Warfarin Dosing in Patients With Cardiac Valve Replacement: The Effects of CYP2C9 and VKORC1 Gene Polymorphisms. Lab Med 2017; 49:25-34. [DOI: 10.1093/labmed/lmx072] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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12
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Dubey AK, Kumar S, Kalita J, Misra UK. To study role of clinical variables and VKORC1 polymorphism in determination of stability of INR in neurological patients on acenocoumarol. CANADIAN JOURNAL OF BIOTECHNOLOGY 2017. [DOI: 10.24870/cjb.2017-a136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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13
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Dagenais R, Wilby KJ, Elewa H, Ensom MHH. Impact of Genetic Polymorphisms on Phenytoin Pharmacokinetics and Clinical Outcomes in the Middle East and North Africa Region. Drugs R D 2017; 17:341-361. [PMID: 28748348 PMCID: PMC5629135 DOI: 10.1007/s40268-017-0195-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Genetic polymorphisms are known to influence outcomes with phenytoin yet effects in the Middle East and North Africa region are poorly understood. OBJECTIVES The objective of this systematic review was to evaluate the impact of genetic polymorphisms on phenytoin pharmacokinetics and clinical outcomes in populations originating from the Middle East and North Africa region, and to characterize genotypic and allelic frequencies within the region for genetic polymorphisms assessed. METHODS MEDLINE (1946-3 May, 2017), EMBASE (1974-3 May, 2017), Pharmacogenomics Knowledge Base, and Public Health Genomics Knowledge Base online databases were searched. Studies were included if genotyping and analyses of phenytoin pharmacokinetics were performed in patients of the Middle East and North Africa region. Study quality was assessed using a National Institutes of Health assessment tool. A secondary search identified studies reporting genotypic and allelic frequencies of assessed genetic polymorphisms within the Middle East and North Africa region. RESULTS Five studies met the inclusion criteria. CYP2C9, CYP2C19, and multidrug resistance protein 1 C3435T variants were evaluated. While CYP2C9*2 and *3 variants significantly reduced phenytoin metabolism, the impacts of CYP2C19*2 and *3 variants were unclear. The multidrug resistance protein 1 CC genotype was associated with drug-resistant epilepsy, but reported impacts on phenytoin pharmacokinetics were conflicting. Appreciable variability in minor allele frequencies existed both between and within countries of the Middle East and North Africa region. CONCLUSIONS CYP2C9 decrease-of-function alleles altered phenytoin pharmacokinetics in patients originating from the Middle East and North Africa region. The impacts of CYP2C19 and multidrug resistance protein 1 C3435T variants on phenytoin pharmacokinetic and clinical outcomes are unclear and require further investigation. Future research should focus on the clinical outcomes associated with phenytoin therapy. PROSPERO 2017: CRD42017057850.
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Affiliation(s)
- Renée Dagenais
- Faculty of Pharmaceutical Sciences, Pharmaceutical Sciences Building, University of British Columbia, Vancouver, BC, Canada
| | - Kyle John Wilby
- College of Pharmacy, Qatar University, PO Box 2713, Doha, Qatar.
| | - Hazem Elewa
- College of Pharmacy, Qatar University, PO Box 2713, Doha, Qatar
| | - Mary H H Ensom
- Faculty of Pharmaceutical Sciences, Pharmaceutical Sciences Building, University of British Columbia, Vancouver, BC, Canada
- Department of Pharmacy, Children's and Women's Health Centre of British Columbia, Vancouver, BC, Canada
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The Impact of Genetic and Non-Genetic Factors on Warfarin Dose Prediction in MENA Region: A Systematic Review. PLoS One 2016; 11:e0168732. [PMID: 27992547 PMCID: PMC5167425 DOI: 10.1371/journal.pone.0168732] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 12/05/2016] [Indexed: 01/13/2023] Open
Abstract
Background Warfarin is the most commonly used oral anticoagulant for the treatment and prevention of thromboembolic disorders. Pharmacogenomics studies have shown that variants in CYP2C9 and VKORC1 genes are strongly and consistently associated with warfarin dose variability. Although different populations from the Middle East and North Africa (MENA) region may share the same ancestry, it is still unclear how they compare in the genetic and non-genetic factors affecting their warfarin dosing. Objective To explore the prevalence of CYP2C9 and VKORC1 variants in MENA, and the effect of these variants along with other non-genetic factors in predicting warfarin dose. Methods In this systematic review, we included observational cross sectional and cohort studies that enrolled patients on stable warfarin dose and had the genetics and non-genetics factors associated with mean warfarin dose as the primary outcome. We searched PubMed, Medline, Scopus, PharmGKB, PHGKB, Google scholar and reference lists of relevant reviews. Results We identified 17 studies in eight different populations: Iranian, Israeli, Egyptian, Lebanese, Omani, Kuwaiti, Sudanese and Turkish. Most common genetic variant in all populations was the VKORC1 (-1639G>A), with a minor allele frequency ranging from 30% in Egyptians and up to 52% and 56% in Lebanese and Iranian, respectively. Variants in the CYP2C9 were less common, with the highest MAF for CYP2C9*2 among Iranians (27%). Variants in the VKORC1 and CYP2C9 were the most significant predictors of warfarin dose in all populations. Along with other genetic and non-genetic factors, they explained up to 63% of the dose variability in Omani and Israeli patients. Conclusion Variants of VKORC1 and CYP2C9 are the strongest predictors of warfarin dose variability among the different populations from MENA. Although many of those populations share the same ancestry and are similar in their warfarin dose predictors, a population specific dosing algorithm is needed for the prospective estimation of warfarin dose.
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Analysis of CYP2C9 polymorphisms (*2 and *3) in warfarin therapy patients in Pakistan. Association of CYP2C9 polymorphisms (*2 and*3) with warfarin dose, age, PT and INR. J Thromb Thrombolysis 2016; 40:218-24. [PMID: 25904339 DOI: 10.1007/s11239-015-1215-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Warfarin is a widely used anticoagulant characterized by having a narrow therapeutic index and exhibiting a wide range of inter-individual and inter-ethnic variation. Single nucleotide polymorphisms in hepatic VKORC1 and CYP2C9 genes causes decreased and increased metabolism of warfarin respectively. The objective of this study was to evaluate the allele frequency of CYP2C9 polymorphic variants *2 and *3 and the association of these allelic variants with PT/INR and daily/weekly dose of warfarin. Seventy-four patients with heart valve replacement were selected. Patients taking low warfarin dose (4.90-17.50 mg weekly) for at least last 3 months and had a stable INR in the range of 2-3 were included in this study. CYP2C9 polymorphism was analyzed by polymerase chain reaction followed by restriction fragment length polymorphism (PCR-RFLP) technique. Among 74 patients, 9 (12.1 %) showed to have *2 allele, whereas 11 (14.1 %) had *3 allele. Genotype frequencies of wild and variant alleles were, 54.1, 17.6, 21.6 and 6.8 % for *1/*1, *1/*2, *1/*3 and *2/*3 respectively. None of the patient was homozygous for *2 and *3. Statistical analysis showed that low warfarin dose (weekly) is significantly associated with *1/*2 and *1/*3 genotypes (p value ≥ 0.001), whereas PT/INR showed no significant association with the any genotypes of CYP2C9. Our study suggest that polymorphic variants of CYP2C9 (*2 and *3) might influence warfarin dose requirements and associated with the low dose of warfarin in patients.
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The effect of CYP2C9 and VKORC1 genetic polymorphisms on warfarin dose requirements in a pediatric population. Anatol J Cardiol 2016; 16:791-796. [PMID: 27182616 PMCID: PMC5324942 DOI: 10.14744/anatoljcardiol.2015.6150] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
OBJECTIVE The aim was to investigate the frequency of genetic polymorphisms of cytochrome P4502C9 (CYP2C9) and vitamin K epoxide reductase complex subunit1 (VKORC1) and determine the effect of these polymorphisms on warfarin dose requirements in pediatric patients. METHODS Fifty-eight pediatric patients with cardiac disease, thrombophilia, or other conditions, taking a stable warfarin dose, aged 0.2-18 years, and with international normalized ratio (INR) between 2 and 3 and 149 healthy children as a control group were included in this prospective, observational study. Patients receiving drugs that interact with warfarin, having chronic liver or renal disease, obesity, or thyroid dysfunctions were excluded. Polymerase chain reaction (real time and restriction fragment length polymorphism) was used to analyze the CYP2C9*2, CYP2C9*3, and VKORC1 polymorphisms. The ideal warfarin dose was calculated according to the patient's age, height, and the presence of CYP2C9*2, CYP2C9*3, and VKORC1 genetic polymorphisms. The mean daily administered doses and ideal doses were compared. Analysis of variance, Student's t-test, logistic regression analysis, and Pearson's correlation analysis were used for statistical analyses. RESULTS The frequency of the CYP2C9 and VKORC1 genetic polymorphisms was determined as CYP2C9*1/*1 (54.6%), *1/*2 (16.4%), *1/*3 (24.2%), *2/*3 (2.9%), *3/*3 (1.9%), wild-type VKORC1 (26.6%), heterozygote alleles (52.7%), and mutant alleles (20.8%). Patients with allelic variants were found to require lower warfarin doses, and a 64.5% correlation was found between the calculated ideal doses and the administered warfarin doses. CONCLUSION Considering CYP2C9 and VKORC1 genetic polymorphisms prior to commencing warfarin treatment will make it easier to reach target INRs and reduce the rate of complications.
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Karaca S, Bozkurt NC, Cesuroglu T, Karaca M, Bozkurt M, Eskioglu E, Polimanti R. International warfarin genotype-guided dosing algorithms in the Turkish population and their preventive effects on major and life-threatening hemorrhagic events. Pharmacogenomics 2015. [PMID: 26216670 DOI: 10.2217/pgs.15.58] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
AIM To determine the accuracy of international warfarin pharmacogenetic algorithms developed on large multiethnic cohorts (comprising more than 1000 subjects) to predict therapeutic warfarin doses in Turkish patients. MATERIALS & METHODS We investigated two Turkish warfarin-treated cohorts: patients with no history of hemorrhagic or thromboembolic event and patients with major and life-threatening hemorrhagic events. RESULTS International pharmacogenetic algorithms showed good performances in predicting the therapeutic dose of patients with no history of bleedings, but they did not significantly detect the incorrect warfarin dose of patients with major and life-threatening hemorrhagic events. CONCLUSION Although genetic information can predict the therapeutic warfarin dose, the accuracy of the international pharmacogenetic algorithms is not sufficient to be used for warfarin screening in Turkish patients.
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Affiliation(s)
- Sefayet Karaca
- School of Health Science, Aksaray University, Aksaray, Turkey.,GENAR Institute for Public Health & Genomics Research, Ankara, Turkey
| | - Nujen Colak Bozkurt
- Department of Endocrinology & Metabolism, Diskapi Yildirim Beyazit Training & Research Hospital, Ankara, Turkey
| | - Tomris Cesuroglu
- GENAR Institute for Public Health & Genomics Research, Ankara, Turkey.,Department of Social Medicine, Maastricht University, Maastricht, The Netherlands
| | - Mehmet Karaca
- Department of Biology, Faculty of Science & Arts, Aksaray University, Aksaray, Turkey
| | - Mehmet Bozkurt
- Department of Cardiology, Ataturk Training & Research Hospital, Ankara, Turkey
| | - Erdal Eskioglu
- Metabolism Unit, Numune Training & Research Hospital, Ankara, Turkey
| | - Renato Polimanti
- Department of Psychiatry, Yale University School of Medicine, West Haven, Connecticut, USA
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VKORC1 and CYP2C9 genotype distribution in Asian countries. Thromb Res 2014; 134:537-44. [DOI: 10.1016/j.thromres.2014.05.028] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Revised: 04/04/2014] [Accepted: 05/16/2014] [Indexed: 01/21/2023]
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Effect of CYP2C9 and VKORC1 genetic variations on warfarin dose requirements in Indian patients. Pharmacol Rep 2014; 65:1375-82. [PMID: 24399734 DOI: 10.1016/s1734-1140(13)71496-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Revised: 04/18/2013] [Indexed: 11/23/2022]
Abstract
BACKGROUND Warfarin, an oral anticoagulant is used in patients who are at increased risk of developing blood clots. The management of warfarin therapy is challenging because it shows large inter and intra individual variability in patient response due to factors like age, gender, diet, concurrent drug interactions and variations in CYP2C9 and VKORC1 genes. Studies implicate that polymorphisms in VKORC1 and CYP2C9 genes are associated with reduced doses of warfarin. The aim of our current study was to characterize the effects of VKORC1 and CYP2C9 gene variations that contribute to variability in warfarin dosing in Indian patients. METHODS Genomic DNA was extracted from 103 patients undergoing warfarin therapy. Their mean daily warfarin dose, INR and demographics were recorded and genotyping of VKORC1 and CYP2C9 gene was performed by PCR-RFLP method. RESULTS Individuals with wild type genotypes required highest mean warfarin dosage of 4.72 mg/day while VKORC1 variants required 3.6 mg/day to maintain their therapeutic INR. CYP2C9*2 genotype was not found to affect the warfarin maintenance dosages. The odds ratio for developing supra therapeutic INR in patients carrying VKORC1 variant allele when compared to wild types was 13.96 (95% CI; 4.85 - 44.65. Other factors affecting warfarin dosages were age and weight. CONCLUSION Inclusion of pharmacogenetic data along with clinical parameters would help better predict warfarin doses in Indian patients.
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Jin B, Hong Y, Zhu J, Li Y, Shi HM. The impact of VKORC1-1639G > A genetic polymorphism upon warfarin dose requirement in different ethnic populations. Curr Med Res Opin 2014; 30:1505-11. [PMID: 24708259 DOI: 10.1185/03007995.2014.912982] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
OBJECTIVE Published data on the association between vitamin K epoxide reductase complex 1 (VKORC1)-1639G > A polymorphism and warfarin dose requirement are inconclusive. To derive a more precise estimation of the relationship, a meta-analysis was performed. METHODS AND RESULTS Studies were identified in English-language articles by search of PubMed and Embase database (inception to July 2013). A total of 32 prospective clinical trials involving 5005 patients were identified and included for analysis. Overall, the weighted mean maintenance dosage of warfarin in patients with the -1639AA genotype decreased 2.62 mg/d compared with that in the -1639GG genotype patients (95% CI -3.10 to -2.14; P < 0.00001) when 24 eligible studies were pooled into the meta-analysis. Furthermore, significantly lower warfarin dose requirement was found in patients with GA genotype versus GG genotype (WMD, -1.32; 95% CI -1.67 to -0.96; P < 0.00001). In the subgroup analysis by ethnicity, statistically significant lower maintenance dosage of warfarin in patients with the AA genotype versus GG genotype were found in both Caucasians (WMD, -2.47; 95% CI -2.92 to -2.03; P < 0.00001) and Asians (WMD, -2.84; 95% CI -4.57 to -1.11; P = 0.001). CONCLUSIONS This meta-analysis indicated that the VKORC1-1639G > A genetic polymorphism is associated with the variation of interindividual warfarin dose requirement in different ethnic populations.
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Affiliation(s)
- Bo Jin
- Department of Cardiology, Huashan Hospital, Fudan University , Shanghai , China
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Zohir N, Afifi R, Ahmed A, Aly Z, Elsobekey M, Kareem H, Helmy R. Role of CYP2C9, VKORC1 and Calumenin Genotypes in Monitoring Warfarin Therapy: An Egyptian Study. Open Access Maced J Med Sci 2013. [DOI: 10.3889/oamjms.2013.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Background: Oral anticoagulant therapy is conditioned by environmental and genetic factors.Objectives: To verify the effect of the calumenin, cytochrome P-450 variants and VKORC1 genetic polymorphisms on the response to warfarin therapy and warfarin dose adjustment.Patients and Methods: We selected fifty warfarin treated patients with dose adjusted at INR value between 2 and 3. PCR-RFLP is used for of calumenin gene polymorphism. Insitu Hybridization was used for identification of VKORC1 promoter and CYP2C9 variants polymorphisms.Results: The warfarin dose in the patients with Calumenin and CYP2C9 genetic polymorphism was lower than the wild type gene. The warfarin dose in the patients with VKORC1 variants was statistically lower compared to that of the wild-type. The presence of combined CYP2C9 genetic variants and VKORC1 polymorphism was associated with lower warfarin dose than that the wild types.Conclusion: Calumenin (CALU) might be a new genetic factor involved in the pharmacogenetics of anticoagulant therapy.
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Krishna Kumar D, Shewade DG, Loriot MA, Beaune P, Balachander J, Sai Chandran BV, Adithan C. Effect of CYP2C9, VKORC1, CYP4F2 and GGCX genetic variants on warfarin maintenance dose and explicating a new pharmacogenetic algorithm in South Indian population. Eur J Clin Pharmacol 2013; 70:47-56. [PMID: 24019055 DOI: 10.1007/s00228-013-1581-x] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Accepted: 08/22/2013] [Indexed: 12/22/2022]
Abstract
OBJECTIVE To determine the influence of genetic polymorphisms on warfarin maintenance dose and to explicate an algorithm using the pharmacogenetic and clinical factors to determine the maintenance and/or starting dose of warfarin in South Indian patients receiving warfarin therapy. METHODS Patients receiving stabilized warfarin therapy (n=257) were included in the study. Single nucleotide polymorphisms (SNPs) of CYP2C9 (rs1799853 and rs1057910), VKORC1 (rs9923231, rs7196161, rs2884737, rs9934438, rs8050894, rs2359612 and rs7294), CYP4F2 (rs2108622) and GGCX (rs11676382) were genotyped by the quantitative real time-PCR method. RESULTS The mean daily maintenance dose of warfarin was found to be 4.7 ± 2.1 mg/day. Patients with the CYP2C9*1/*2, *1/*3 and *2/*3 variant genotypes required a 51.0 (2.8 mg), 60.9 (2.3 mg) and 62.2 % (2.2 mg) lower daily maintenance dose of warfarin, respectively, than those patients with the CYP2C9*1/*1 wild-type genotype (5.2 mg) (p<0.0001). The genetic variants of CYP2C9, VKORC1 and GGCX were associated with decreased warfarin dose, except for rs7196161, rs7294 and rs2108622 which were associated with an increased warfarin dose. Genetic variations of CYP2C9 (*2 and *3), VKORC1 (rs9923231, rs7294, rs9934438 and rs2359612), CYP4F2, GGCX and non-genetic factors such as age, body weight, clinical status (post mechanical valve replacement) could explain up to 62.1 % of the overall variation (adjusted r (2) 60.2 %, p<0.0001) in warfarin maintenance dose. CONCLUSION Genetic polymorphisms of CYP2C9, VKORC1, CYP4F2 and GGCX are important predictive factors of warfarin maintenance dose, and the developed algorithm will be useful to predict the required maintenance and/or starting warfarin dose in South Indian populations.
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Affiliation(s)
- Dhakchinamoorthi Krishna Kumar
- Department of Pharmacology, Jawaharlal Institute of Postgraduate Medical Education & Research (JIPMER), Pondicherry, 605 006, India,
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Bazan NS, Sabry NA, Rizk A, Mokhtar S, Badary OA. Factors affecting warfarin dose requirements and quality of anticoagulation in adult Egyptian patients: role of gene polymorphism. Ir J Med Sci 2013; 183:161-72. [DOI: 10.1007/s11845-013-0978-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Accepted: 06/11/2013] [Indexed: 12/22/2022]
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Esmerian MO, Mitri Z, Habbal MZ, Geryess E, Zaatari G, Alam S, Skouri HN, Mahfouz RA, Taher A, Zgheib NK. Influence ofCYP2C9andVKORC1Polymorphisms on Warfarin and Acenocoumarol in a Sample of Lebanese People. J Clin Pharmacol 2013; 51:1418-28. [DOI: 10.1177/0091270010382910] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Özer M, Demirci Y, Hızel C, Sarıkaya S, Karaltı İ, Kaspar Ç, Alpan S, Genç E. Impact of Genetic Factors (CYP2C9,VKORC1andCYP4F2) on Warfarin Dose Requirement in the Turkish Population. Basic Clin Pharmacol Toxicol 2012; 112:209-14. [DOI: 10.1111/bcpt.12024] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Accepted: 10/02/2012] [Indexed: 11/30/2022]
Affiliation(s)
- Mahmut Özer
- Department of Pharmacology; Yeditepe University; Atasehir; Istanbul; Turkey
| | - Yeliz Demirci
- Department of Pharmacology; Yeditepe University; Atasehir; Istanbul; Turkey
| | | | - Sabit Sarıkaya
- Department of Cardiac Surgery; Kartal Kosuyolu Education and Research Hospital; Cevizli; Kartal; Istanbul; Turkey
| | - İskender Karaltı
- Department of Clinical Microbiology; Yeditepe University; Atasehir; Istanbul; Turkey
| | - Çiğdem Kaspar
- Department of Biostatistics; Yeditepe University; Atasehir; Istanbul; Turkey
| | - Serdar Alpan
- Department of Pharmacology; Yeditepe University; Atasehir; Istanbul; Turkey
| | - Ece Genç
- Department of Pharmacology; Yeditepe University; Atasehir; Istanbul; Turkey
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The prevalence of VKORC1 1639 G>A and CYP2C9*2*3 genotypes in patients that requiring anticoagulant therapy in Turkish population. Mol Biol Rep 2012; 39:11017-22. [PMID: 23065265 DOI: 10.1007/s11033-012-2004-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2012] [Accepted: 10/01/2012] [Indexed: 12/28/2022]
Abstract
The aim was to investigate the prevalence of VKORC1 and CYP2C9 genotypes in patients requiring anticoagulant therapy in two different region's populations of Turkey. The recent cohort included 292 patients that needed anticoagulant therapy, and who had a history of deep vein thrombosis and/or pulmonary artery thromboembolism. Genomic DNA was isolated from peripheral blood samples and the StripAssay reverse hybridization or Real Time PCR technique was used for genotype analysis. Genotypes for CYP2C9 were detected as follows: 165 (56.5 %) for CYP2C9*1/*1, 67 (23.0 %) for CYP2C9*1/*2, 25 (8.6 %) for CYP2C9*1/*3, 9 (3.0 %) for CYP2C9*2/*2, 21 (7.2 %) for CYP2C9*2/*3, 5(1.7 %) for CYP2C9*3/*3 for CYP2C9 and the allele frequencies were: 0.723 for allele*1, 0.182 for allele*2 and 0.095 for allele*3 respectively. Genotypes for VKORC1 were detected as follows: 64 (21.9 %) for GG, 220 (75.4 %) for GA and 8 (2.7 %) for AA alleles. The G allele frequency was detected as 0.596, and the A allele frequency was 0.404. The VKORC1 1639 G>A and CYP2C9 mutation prevalence and allele frequency of the current results from two different populations (Sivas and Canakkale) showed similarly very variable profiles when compared to the other results from the Turkish population.
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Fung E, Patsopoulos NA, Belknap SM, O'Rourke DJ, Robb JF, Anderson JL, Shworak NW, Moore JH. Effect of genetic variants, especially CYP2C9 and VKORC1, on the pharmacology of warfarin. Semin Thromb Hemost 2012; 38:893-904. [PMID: 23041981 DOI: 10.1055/s-0032-1328891] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The genes encoding the cytochrome P450 2C9 enzyme (CYP2C9) and vitamin K-epoxide reductase complex unit 1 (VKORC1) are major determinants of anticoagulant response to warfarin. Together with patient demographics and clinical information, they account for approximately one-half of the warfarin dose variance in individuals of European descent. Recent prospective and randomized controlled trial data support pharmacogenetic guidance with their use in warfarin dose initiation and titration. Benefits from pharmacogenetics-guided warfarin dosing have been reported to extend beyond the period of initial dosing, with supportive data indicating benefits to at least 3 months. The genetic effects of VKORC1 and CYP2C9 in African and Asian populations are concordant with those in individuals of European ancestry; however, frequency distribution of allelic variants can vary considerably between major populations. Future randomized controlled trials in multiethnic settings using population-specific dosing algorithms will allow us to further ascertain the generalizability and cost-effectiveness of pharmacogenetics-guided warfarin therapy. Additional genome-wide association studies may help us to improve and refine dosing algorithms and potentially identify novel biological pathways.
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Affiliation(s)
- Erik Fung
- Section of Cardiology, Heart & Vascular Center, Lebanon, New Hampshire 03756, USA.
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Jorgensen AL, FitzGerald RJ, Oyee J, Pirmohamed M, Williamson PR. Influence of CYP2C9 and VKORC1 on patient response to warfarin: a systematic review and meta-analysis. PLoS One 2012; 7:e44064. [PMID: 22952875 PMCID: PMC3430615 DOI: 10.1371/journal.pone.0044064] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Accepted: 07/30/2012] [Indexed: 01/13/2023] Open
Abstract
Background Warfarin is a highly effective anticoagulant however its effectiveness relies on maintaining INR in therapeutic range. Finding the correct dose is difficult due to large inter-individual variability. Two genes, CYP2C9 and VKORC1, have been associated with this variability, leading to genotype-guided dosing tables in warfarin labeling. Nonetheless, it remains unclear how genotypic information should be used in practice. Navigating the literature to determine how genotype will influence warfarin response in a particular patient is difficult, due to significant variation in patient ethnicity, outcomes investigated, study design, and methodological rigor. Our systematic review was conducted to enable fair and accurate interpretation of which variants affect which outcomes, in which patients, and to what extent. Methodology/Principal Findings A comprehensive search strategy was applied and 117 studies included. Primary outcomes were stable dose, time to stable dose and bleeding events. Methodological quality was assessed using criteria of Jorgensen and Williamson and data synthesized in meta-analyses using advanced methods. Pooled effect estimates were significant in most ethnic groups for CYP2C9*3 and stable dose (mutant types requiring between 1.1(0.7–1.5) and 2.3 (1.6–3.0)mg/day). Effect estimates were also significant for VKORC1 and stable dose for most ethnicities, although direction differed between asians and non-asians (mutant types requiring between 0.8(0.4–1.3) and 1.5(1.1–1.8)mg/day more in asians and between 1.5(0.7–2.2) and 3.1(2.7–3.6)mg/day less in non-asians). Several studies were excluded due to inadequate data reporting. Assessing study quality highlighted significant variability in methodological rigor. Notably, there was significant evidence of selective reporting, of outcomes and analysis approaches. Conclusions/Significance Genetic associations with warfarin response vary between ethnicities. In order to achieve unbiased estimates in different populations, a high level of methodological rigor must be maintained and studies should report sufficient data to enable inclusion in meta-analyses. We propose minimum reporting requirements, suggest methodological guidelines and provide recommendations for reducing the risk of selective reporting.
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Affiliation(s)
- Andrea L Jorgensen
- Department of Biostatistics, Shelley's Cottage, University of Liverpool, Liverpool, United Kingdom.
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Rathore SS, Agarwal SK, Pande S, Singh SK, Mittal T, Mittal B. Therapeutic dosing of acenocoumarol: proposal of a population specific pharmacogenetic dosing algorithm and its validation in north Indians. PLoS One 2012; 7:e37844. [PMID: 22629463 PMCID: PMC3358293 DOI: 10.1371/journal.pone.0037844] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Accepted: 04/25/2012] [Indexed: 11/23/2022] Open
Abstract
Objectives To develop a population specific pharmacogenetic acenocoumarol dosing algorithm for north Indian patients and show its efficiency in dosage prediction. Methods Multiple and linear stepwise regression analyses were used to include age, sex, height, weight, body surface area, smoking status, VKORC1 -1639 G>A, CYP4F2 1347 G>A, CYP2C9*2,*3 and GGCX 12970 C>G polymorphisms as variables to generate dosing algorithms. The new dosing models were compared with already reported algorithms and also with the clinical data for various performance measures. Odds ratios for association of genotypes with drug sensitive and resistant groups were calculated. Results The pharmacogenetic dosing algorithm generated by multiple regression analysis explains 41.4% (p-value <0.001) of dosage variation. Validation of the new algorithm showed its predictive ability to be better than the already established algorithms based on similar variables. Its validity in our population is reflected by increased sensitivity, specificity, accuracy and decreased rates of over- and under- estimation in comparison to clinical data. The VKORC1-1639 G>A polymorphism was found to be strongly associated with acenocoumarol sensitivity according to recessive model. Conclusions We have proposed an efficient north India specific pharmacogenetic acenocoumarol dosing algorithm which might become a baseline for personalised medicine approach for treatment of patients in future.
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Affiliation(s)
- Saurabh Singh Rathore
- Department of Genetics, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India
| | - Surendra Kumar Agarwal
- Cardio-Vascular and Thoracic Surgery, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India
| | - Shantanu Pande
- Cardio-Vascular and Thoracic Surgery, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India
| | - Sushil Kumar Singh
- Thoracic and Cardio-Vascular Surgery, Chhatrapati Shahuji Maharaj Medical University, Lucknow, India
| | - Tulika Mittal
- Department of Genetics, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India
| | - Balraj Mittal
- Department of Genetics, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India
- * E-mail:
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Zhang W, Zhang WJ, Zhu J, Kong FC, Li YY, Wang HY, Yang YH, Wang C. Genetic polymorphisms are associated with variations in warfarin maintenance dose in Han Chinese patients with venous thromboembolism. Pharmacogenomics 2012; 13:309-21. [PMID: 22248286 DOI: 10.2217/pgs.11.147] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
AIM Warfarin is a clinical anticoagulant that requires periodic monitoring because it is associated with adverse outcomes. Personalized medicine, which is based on pharmacogenetics, holds great promise in solving these types of problems. It aims to provide the tools and knowledge to tailor drug therapy to an individual patient, with the potential of increasing safety and efficacy of medications. MATERIALS & METHODS In the present study we analyzed genotypes of 14 SNPs for seven genes using DNA from 297 Han Chinese venous thromboembolism patients treated with warfarin. RESULTS Multiple regression analyses revealed that CYP2C9 genotype (p = 0.001), VKORC1 genotype (p < 0.001), age (p < 0.01) and weight (p < 0.001) were all associated with warfarin dose requirements, which can explain 37.4% of the variability of warfarin dose among Han Chinese patients. Meanwhile, in the validation cohort, the predicted warfarin daily dose was calculated using the best model with a 64.5% predicted dose being acceptable (-1 mg/day ≤Δwarfarin dose ≤1 mg/day). CONCLUSION We developed a pharmacogenetic dose algorithm for warfarin treatment that uses genotypes from two genes (VKORC1 and CYP2C9) and clinical variables to predict therapeutic maintenance doses in Chinese patients with venous thromboembolism. The validity of the dosing algorithm was confirmed in a cohort of venous thromboembolism patients on warfarin therapy.
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Affiliation(s)
- Wei Zhang
- Beijing Xiaotangshan Hospital, Xiaotangshan Town, Changping District, Beijing 102211, China
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Martins MAP, Carlos PPS, Ribeiro DD, Nobre VA, César CC, Rocha MOC, Ribeiro ALP. Warfarin drug interactions: a comparative evaluation of the lists provided by five information sources. Eur J Clin Pharmacol 2011; 67:1301-8. [PMID: 21701882 DOI: 10.1007/s00228-011-1086-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Accepted: 06/08/2011] [Indexed: 01/27/2023]
Abstract
PURPOSE Detecting potential drug interactions can lead to early interventions that protect patients from serious drug-related problems. The aim of this study was to evaluate the agreement among the lists of warfarin interactions provided by five information sources. METHODS The lists of warfarin interactions and the corresponding severity ratings and documentation levels presented by the three compendia and by the World Health Organization (WHO) Model Formulary were all compared, and each list was compared to that provided on the package insert of Marevan, a brand of warfarin. The compendia used were: Drug Interaction Facts, Drug Interactions: Analysis and Management and DRUG-REAX. A kappa coefficient was used to calculate the agreement among the sources. RESULTS A total of 537 interactions were listed. Only 13 (2.4%) were common to the five sources. The global Fleiss' kappa coefficient was -0.0080, which indicated poor agreement. Eleven warfarin interactions appeared only in the Marevan package insert. Importantly, 243 interactions (45.3% of the total) were deemed significant in at least one compendium. Only two warfarin interactions were reported as critical by all three compendia and by WHO. The most critical interactions cited by the compendia were missing from the package insert. CONCLUSIONS Poor agreement was found among five sources listing warfarin interactions. Potentially severe clinical consequences might occur due to these discrepant recommendations. Finally, the lack of standard terminology and clinical guidance, as well as the possible inaccuracy of severity ratings and documentation might contribute to heterogeneous procedures in clinical practice.
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Affiliation(s)
- Maria A P Martins
- Faculdade de Medicina, Hospital das Clínicas, Universidade Federal de Minas Gerais, Av. Prof. Alfredo Balena, 190, Belo Horizonte, MG 30130-100, Brazil
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Shin J, Cao D. Comparison of warfarin pharmacogenetic dosing algorithms in a racially diverse large cohort. Pharmacogenomics 2011; 12:125-34. [PMID: 21174627 DOI: 10.2217/pgs.10.168] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
AIMS Multiple warfarin pharmacogenetic dosing algorithms have been reported to date. However, there is only limited information available on the performance of the algorithms that can be used with the results of a US FDA-cleared warfarin pharmacogenetic test. We compared the performance of warfarin pharmacogenetic dosing algorithms in a large racially diverse cohort. MATERIALS & METHODS Warfarin pharmacogenetic dosing algorithms were identified using the PubMed database. Patient information from the International Warfarin Pharmacogenetics Consortium database was used to predict therapeutic warfarin doses according to each algorithm. By using bootstrapping analysis, the performance of algorithms was tested by comparing the mean absolute error and mean percentage of patients whose predicted dose fell within 20% of actual dose (percentage within 20%) in the entire cohort, and by race and therapeutic dose range. RESULTS A total of 13 algorithms and 1940 patients were included in the study. Overall, all the algorithms had similar performances (mean absolute error: 10.3 mg/week and mean percentage within 20%-41.4%). However, algorithms derived from racially mixed populations tended to perform better than those derived from single race populations. Mixed population algorithms had the lowest mean absolute error and the highest percentage within 20% across the racial groups. Most algorithms performed better in the intermediate-dose range (between 21 and 49 mg/week) than in the low (≤21 mg/week) or high-(≥49 mg/week) range. CONCLUSION Published warfarin pharmacogenetic algorithms performed similarly, although mixed population algorithms tended to perform better than race-specific algorithms.
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Affiliation(s)
- Jaekyu Shin
- Department of Clinical Pharmacy, School of Pharmacy, 521 Parnassus Avenue, University of California, San Francisco, CA 94143-90622, USA.
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The impact of CYP2C9 and VKORC1 genetic polymorphism and patient characteristics upon warfarin dose requirements in an adult Turkish population. Heart Vessels 2010; 25:155-62. [DOI: 10.1007/s00380-009-1177-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2008] [Accepted: 06/12/2009] [Indexed: 10/19/2022]
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Yang L, Ge W, Yu F, Zhu H. Impact of VKORC1 gene polymorphism on interindividual and interethnic warfarin dosage requirement--a systematic review and meta analysis. Thromb Res 2009; 125:e159-66. [PMID: 19942260 DOI: 10.1016/j.thromres.2009.10.017] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2008] [Revised: 09/17/2009] [Accepted: 10/26/2009] [Indexed: 10/20/2022]
Abstract
INTRODUCTION Warfarin is the most widely used oral anticoagulant. It has been suggested that anticoagulation effect of warfarin is significantly associated with the polymorphism of certain genes, including Cytochrome P450 complex subunit 2C9 (CYP2C9), Vitamin K Epoxide Reductase Complex Subunit 1 (VKORC1), Gamma-Glutamyl Carboxylase (GGCX) and Apolipoprotein E (APOE) etc. The purpose of the present study was to conduct a systemic review and meta-analysis to investigate the relationship between mean daily warfarin dose (MDWD) and VKORC1 single nucleotide polymorphisms (SNPs). MATERIALS AND METHODS Inclusion and exclusion criteria were made, and the studies between 2004 and present were searched. References were examined, and experts were consulted for additional information. Data were extracted. Revman 4.2.10 software was applied to analyze the relationship between MDWD and VKORC1 SNPs. RESULTS Total 19 studies were included in the meta-analysis. The frequencies of 1173TT and -1639 AA in Asian patients were higher than those in Caucasian and African populations. Patients with VKORC1 1173 CT and 1173 CC required 44% [95% Confidence Interval (CI); 32%, 56%] and 97% [73%, 122%] higher MDWD than 1173 TT carriers, -1639GA and -1639GG carriers required 52% [41%, 64%] and 102% [85%, 118%] higher MDWD than -1639AA carriers, 3730GA and 3730AA carriers required 27% [3%, 58%] and 52% [3%, 109%] higher MDWD than 3730GG carriers. In addition, 1173C, -1639 G and 3730 A carriers required 63% [44%, 82%], 61% [49%, 73%] and 32% [4%, 59%] higher MDWD than 1173TT, -1639 AA and 3730GG, respectively. Sensitive analyses demonstrated that the impacts of gene polymorphism on warfarin dosage requirement were significantly different between Caucasian and Asian population, and the results of meta-analyses were stable and reliable. CONCLUSION This is the first meta-analysis about the impact of VKORC1 gene polymorphism on warfarin dose requirement. Our studies showed that gene polymorphisms of VKORC1 significantly associated with the variation of interindividual warfarin dose requirement variation, and the effects are different in ethnicities.
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Affiliation(s)
- Limei Yang
- Pharmacy Department, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
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Sipeky C, Csongei V, Jaromi L, Safrany E, Polgar N, Lakner L, Szabo M, Takacs I, Melegh B. Vitamin K epoxide reductase complex 1 (VKORC1) haplotypes in healthy Hungarian and Roma population samples. Pharmacogenomics 2009; 10:1025-32. [PMID: 19530970 DOI: 10.2217/pgs.09.46] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The aim of this work was to determine the VKORC1 haplotype profile in healthy Hungarian and Roma population samples, and to compare our data with other selected populations. Using haplotype tagging SNPs (G-1639A, G9041A and C6009T), we characterized Hungarian (n = 510) and Roma (n = 451) population samples with regard to VKORC1*1, *2, *3 and *4 haplotypes. In the Hungarian samples, the VKORC1*1, *2, *3 and *4 haplotypes accounted for 3, 39, 37 and 21%, respectively and by contrast, in the Roma population samples the VKORC1 variants were 5, 30, 46 and 19%, respectively. Comparing the genotypes of Roma and Hungarian populations, difference was found in the *2/*2 (6.87 vs 13.5%), *2/*4 (13.9 vs 19.2%) and *3*3 (21.9 vs 13.7%) VKORC1 haplotype combinations. Comparing each group with the others, and our data with findings published previously by other groups, the VKORC1 genetic profile in Hungarians was more similar to European Caucasians and Americans with European descent than to Roma samples. Clear differences could be detected between Roma versus Hungarians and European or American Caucasians; the Roma population had only minor similarities with data from India.
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Affiliation(s)
- Csilla Sipeky
- University of Pecs, Department of Medical Genetics and Child Development, H-7624 Pecs, Szigeti 12, Hungary
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Zhou SF, Zhou ZW, Huang M. Polymorphisms of human cytochrome P450 2C9 and the functional relevance. Toxicology 2009; 278:165-88. [PMID: 19715737 DOI: 10.1016/j.tox.2009.08.013] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2009] [Revised: 08/18/2009] [Accepted: 08/21/2009] [Indexed: 12/19/2022]
Abstract
Human cytochrome P450 2C9 (CYP2C9) accounts for ∼20% of hepatic total CYP content and metabolizes ~15% clinical drugs such as phenytoin, S-warfarin, tolbutamide, losartan, and many nonsteroidal anti-inflammatory agents (NSAIDs). CYP2C9 is highly polymorphic, with at least 33 variants of CYP2C9 (*1B through *34) being identified so far. CYP2C9*2 is frequent among Caucasians with ~1% of the population being homozygous carriers and 22% are heterozygous. The corresponding figures for the CYP2C9*3 allele are 0.4% and 15%, respectively. There are a number of clinical studies addressing the impact of CYP2C9 polymorphisms on the clearance and/or therapeutic response of therapeutic drugs. These studies have highlighted the importance of the CYP2C9*2 and *3 alleles as a determining factor for drug clearance and drug response. The CYP2C9 polymorphisms are relevant for the efficacy and adverse effects of numerous NSAIDs, sulfonylurea antidiabetic drugs and, most critically, oral anticoagulants belonging to the class of vitamin K epoxide reductase inhibitors. Warfarin has served as a practical example of how pharmacogenetics can be utilized to achieve maximum efficacy and minimum toxicity. For many of these drugs, a clear gene-dose and gene-effect relationship has been observed in patients. In this regard, CYP2C9 alleles can be considered as a useful biomarker in monitoring drug response and adverse effects. Genetic testing of CYP2C9 is expected to play a role in predicting drug clearance and conducting individualized pharmacotherapy. However, prospective clinical studies with large samples are warranted to establish gene-dose and gene-effect relationships for CYP2C9 and its substrate drugs.
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Affiliation(s)
- Shu-Feng Zhou
- School of Health Sciences, RMIT University, Victoria 3083, Australia.
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Passetti F, Ferreira CG, Costa FF. The impact of microRNAs and alternative splicing in pharmacogenomics. THE PHARMACOGENOMICS JOURNAL 2009; 9:1-13. [PMID: 19156160 DOI: 10.1038/tpj.2008.14] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- F Passetti
- Laboratory of Bioinformatics and Computational Biology, Division of Clinical and Translational Research, Research Coordination (CPQ), Instituto Nacional de Câncer, Rio de Janeiro, Brazil
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