| 1. |
- Wadelius, Mia, et al.
(författare)
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Common VKORC1 and GGCX polymorphisms associated with warfarin dose
- 2005
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Ingår i: The Pharmacogenomics Journal. - : Springer Science and Business Media LLC. - 1470-269X .- 1473-1150. ; 5:4, s. 262-70
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Tidskriftsartikel (refereegranskat)abstract
- We report a novel combination of factors that explains almost 60% of variable response to warfarin. Warfarin is a widely used anticoagulant, which acts through interference with vitamin K epoxide reductase that is encoded by VKORC1. In the next step of the vitamin K cycle, gamma-glutamyl carboxylase encoded by GGCX uses reduced vitamin K to activate clotting factors. We genotyped 201 warfarin-treated patients for common polymorphisms in VKORC1 and GGCX. All the five VKORC1 single-nucleotide polymorphisms covary significantly with warfarin dose, and explain 29-30% of variance in dose. Thus, VKORC1 has a larger impact than cytochrome P450 2C9, which explains 12% of variance in dose. In addition, one GGCX SNP showed a small but significant effect on warfarin dose. Incorrect dosage, especially during the initial phase of treatment, carries a high risk of either severe bleeding or failure to prevent thromboembolism. Genotype-based dose predictions may in future enable personalised drug treatment from the start of warfarin therapy.The Pharmacogenomics Journal advance online publication, 10 May 2005; doi:10.1038/sj.tpj.6500313.
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| 2. |
- Wadelius, Mia, et al.
(författare)
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Warfarin sensitivity related to CYP2C9, CYP3A5, ABCB1 (MDR1) and other factors
- 2004
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Ingår i: The Pharmacogenomics Journal. - : Springer Science and Business Media LLC. - 1470-269X .- 1473-1150. ; 4:1, s. 40-8
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Tidskriftsartikel (refereegranskat)abstract
- The required dose of the oral anticoagulant warfarin varies greatly, and overdosing often leads to bleeding. Warfarin is metabolised by cytochrome P450 enzymes CYP2C9, CYP1A2 and CYP3A. The target cell level of warfarin may be dependent on the efflux pump P-glycoprotein, encoded by the adenosine triphosphate-binding cassette gene ABCB1 (multidrug resistance gene 1). Genetic variability in CYP2C9, CYP3A5 and ABCB1 was analysed in 201 stable warfarin-treated patients using solid-phase minisequencing, pyrosequencing and SNaPshot. CYP2C9 variants, age, weight, concurrent drug treatment and indication for treatment significantly influenced warfarin dosing in these patients, explaining 29% of the variation in dose. CYP3A5 did not affect warfarin dosing. An ABCB1 haplotype containing the exon 26 3435T variant was over-represented among low-dose patients. Thirty-six patients with serious bleeding complications had higher prothrombin time international normalised ratios than 189 warfarin-treated patients without serious bleeding, but there were no significant differences in CYP2C9, CYP3A5 or ABCB1 genotypes and allelic variants.
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| 3. |
- Hallberg, Pär, 1974-, et al.
(författare)
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SWEDEGENE : a Swedish nation-wide DNA sample collection for pharmacogenomic studies of serious adverse drug reactions
- 2020
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Ingår i: The Pharmacogenomics Journal. - : Springer Science and Business Media LLC. - 1470-269X .- 1473-1150. ; 20:4, s. 579-585
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Tidskriftsartikel (refereegranskat)abstract
- SWEDEGENE is a Swedish nation-wide sample collection established to facilitate studies of clinical and genetic risk factors for adverse drug reactions (ADRs). Most cases are recruited among patients reported to the ADR registry at the Swedish Medical Products Agency by health-care professionals. Clinical data are collected both from medical and laboratory records and through interviews using standardized questionnaires. Genome-wide scans and whole-genome sequencing are done, and association studies are conducted using mainly controls from the Swedish TwinGene biobank with data on diagnoses and prescribed drugs. SWEDEGENE was established in 2008 and currently contains DNA and information from about 2550 adults who have experienced specific ADRs, and from 580 drug exposed controls. Results from genome-wide association studies have now been published, and data from whole-genome sequencing are being analyzed. SWEDEGENE has the potential to offer a new means of developing individualized and safe drug therapy through patient pre-treatment screening.
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| 4. |
- Jacobson, Annica, et al.
(författare)
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Can mutations in ELA2, neutrophil elastase expression or differential cell toxicity explain sulphasalazine-induced agranulocytosis?
- 2004
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Ingår i: BMC Blood Disorders. - : Springer Science and Business Media LLC. - 1471-2326. ; 4:1, s. 5-
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Drug-induced agranulocytosis, a severe side effect marked by a deficit or absolute lack of granulocytic white blood cells, is a rare side-effect of the anti-inflammatory drug sulphasalazine. Mutations in the human neutrophil elastase gene (ELA2), causing increased intracellular concentration of this serine protease, inhibits neutrophil differentiation in severe congenital neutropenia (SCN). Since the clinical symptoms of agranulocytosis and SCN are similar, we hypothesized that it may origin from a common genetic variation in ELA2 or that sulphasalazine may affect human neutrophil elastase activity and protein expression. METHODS: We screened for genetic differences in ELA2 in DNA from 36 patients who had suffered from sulphasalazine-induced agranulocytosis, and compared them with 72 patients treated with sulphasalazine without blood reactions. We also performed in vitro studies of the blood cell lines HL60 and U937 after sulphasalazine exposure with respect to cell survival index, neutrophil elastase protein expression and activity. RESULTS: None of the mutations in ELA2, which previously have been reported to be associated with SCN, was found in this material. Protein expression of human neutrophil elastase in lymphoma U937 cells was not affected by treatment with concentrations equivalent to therapeutic doses. Cell survival of lymphoma U937 and promyelocytic leukemia HL-60 cells was not affected in this concentration range, but exhibited a decreased proliferative capacity with higher sulphasalazine concentrations. Interestingly the promyelocytic cells were more sensitive to sulphasalazine than the lymphoma cell line. CONCLUSION: Neutrophil elastase expression and ELA2 mutations do, however, not seem to be involved in the etilogy of sulphasalazine-induced agranulocytosis. Why sulphasalazine is more toxic to promyelocytes than to lymphocytes remains to be explained.
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| 5. |
- Kharazmi, Mohammad, et al.
(författare)
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A Genome-Wide Association Study of Bisphosphonate-Associated Atypical Femoral Fracture
- 2019
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Ingår i: Calcified Tissue International. - : SPRINGER. - 0171-967X .- 1432-0827. ; 105:1, s. 51-67
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Tidskriftsartikel (refereegranskat)abstract
- Atypical femoral fracture is a well-documented adverse reaction to bisphosphonates. It is strongly related to duration of bisphosphonate use, and the risk declines rapidly after drug withdrawal. The mechanism behind bisphosphonate-associated atypical femoral fracture is unclear, but a genetic predisposition has been suggested. With the aim to identify common genetic variants that could be used for preemptive genetic testing, we performed a genome-wide association study. Cases were recruited mainly through reports of adverse drug reactions sent to the Swedish Medical Products Agency on a nation-wide basis. We compared atypical femoral fracture cases (n=51) with population-based controls (n=4891), and to reduce the possibility of confounding by indication, we also compared with bisphosphonate-treated controls without a current diagnosis of cancer (n=324). The total number of single-nucleotide polymorphisms after imputation was 7,585,874. A genome-wide significance threshold of p<5x10(-8) was used to correct for multiple testing. In addition, we performed candidate gene analyses for a panel of 29 genes previously implicated in atypical femoral fractures (significance threshold of p<5.7x10(-6)). Compared with population controls, bisphosphonate-associated atypical femoral fracture was associated with four isolated, uncommon single-nucleotide polymorphisms. When cases were compared with bisphosphonate-treated controls, no statistically significant genome-wide association remained. We conclude that the detected associations were either false positives or related to the underlying disease, i.e., treatment indication. Furthermore, there was no significant association with single-nucleotide polymorphisms in the 29 candidate genes. In conclusion, this study found no evidence of a common genetic predisposition for bisphosphonate-associated atypical femoral fracture. Further studies of larger sample size to identify possible weakly associated genetic traits, as well as whole exome or whole-genome sequencing studies to identify possible rare genetic variation conferring a risk are warranted.
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