Role of CYP2C9, VKORC1 and Calumenin Genotypes in Monitoring Warfarin Therapy: An Egyptian Study


  • Naguib Zohir Cairo University, Clinical and Chemical Pathology, 542 ElKhazan street, Cairo 24434
  • Reham Afifi Cairo University, Clinical and Chemical Pathology, 542 ElKhazan street, Cairo 24434
  • Asmaa Ahmed Cairo University, Clinical and Chemical Pathology, 542 ElKhazan street, Cairo 24434
  • Zinab Aly Cairo University, Clinical and Chemical Pathology, 542 ElKhazan street, Cairo 24434
  • Mehry Elsobekey Opthalmology Institute, Opthalmology, Cairo
  • Heba Kareem Cairo University, Internal Medicine, Cairo
  • Rehab Helmy Cairo University, Clinical and Chemical Pathology, 542 ElKhazan street, Cairo 24434



Warfarin, VKORC1, Calumenin, CYP2C9, Gene, polymorphism.


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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How to Cite

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 [Internet]. 2013 Dec. 15 [cited 2021 Apr. 12];1(1):76-82. Available from:



B - Clinical Sciences