Genotyping of CYP2C9 and VKORC1 in the Arabic Population of Al-Ahsa, Saudi Arabia

Abstract EN

Polymorphisms in the genes encoding CYP2C9 enzyme and VKORC1 reductase significantly influence the dose variability of coumarinic oral anticoagulants (COAs).

Substantial inter- and intraethnic variability exists in the frequencies of CYP2C9∗2 and ∗3 and VKORC1 –1639A alleles.

However, the prevalence of CYP2C9 and VKORC1 genetic variants is less characterized in Arab populations.

A total of 131 healthy adult subjects from the Al-Ahsa region of Saudi Arabia were genotyped for the CYP2C9∗2 and ∗3 and VKORC1 –1639G>A polymorphisms by PCR-RFLP method.

The frequencies of the CYP2C9∗2 and ∗3 and VKORC1 –1639A alleles were 13.3%, 2.3%, and 42.4%, respectively, with no subjects carrying 2 defective alleles.

The frequencies of the CYP2C9∗3 and VKORC1 –1639A alleles were significantly lower than those reported in different Arabian populations.

None of the subjects with the VKORC1 –1639AA genotype were carriers of CYP2C9∗1/∗3 genotypes that lead to sensitivity to COAs therapy.

The low frequency of the CYP2C9∗3 allele combined with the absence of subjects carrying 2 defective CYP2C9 alleles suggests that, in this specific population, pharmacogenetic COAs dosing may mostly rely upon VKORC1 genotyping.