background: cytochrome p450 2c19 (cyp2c19) is important in metabolism of wide range of drugs. cyp2c19*17 is a novel variant allele which increases gene transcription and therefore results in ultra-rapid metabolizer phenotype (urm). distribution of this variant allele has not been well studied worldwide. the aim of present study was to investigate allele and genotype frequencies of cyp2c19*17 in...

BACKGROUND The polymorphisms of cytochrome P450 2C19 (CYP2C19) gene are major prognostic factors for the response to clopidogrel therapy in patients with coronary artery diseases (CAD). The CYP2C19*2 is the most important allele responsible for resistance to clopidogrel therapy. This study examined CYP2C19 gene polymorphism (CYP2C19*1 and *2) in Iranian patients. METHODS This cross-sectional ...

CYP2C19 rs12769205 alters an intron 2 branch point adenine leading to an alternative mRNA in human liver with complete inclusion of intron 2 (exon 2B). rs12769205 changes the mRNA reading frame, introduces 87 amino acids, and leads to a premature stop codon. The 1000 Genomes project (http://browser.1000genomes.org/index.html) indicated rs12769205 is in linkage disequilibrium with rs4244285 on C...

Background. The CYP2C19∗2 allele may be associated with a reduced antiplatelet effect for clopidogrel. Here, we assessed whether CYP2C19∗2 alleles correlate with clopidogrel responsiveness following the administration of clopidogrel in healthy Malaysian volunteers. Methods. Ninety volunteers were genotyped for CYP2C19∗2 and CYP2C19∗3 alleles. Forty-five of 90 volunteers were included in the clo...

Polymorphisms in the cytochrome P (CYP) 450 family may cause adverse drug responses in individuals. Cytochrome P450 2C19 (CYP2C19) is a member of the CYP family, where the presence of the 681 G>A, 636 G>A and 806 C>T polymorphisms result in the CYP2C19*2, CYP2C19*3 and CYP2C19*17 alleles, respectively. In the current study, the frequency of the CYP2C19*2, CYP2C19*3 and CYP2C19*17 alleles in an ...

A genetic polymorphism in the metabolism of the anticonvulsant drug S-mephenytoin has been attributed to defective CYP2C19 alleles. This genetic polymorphism displays large interracial differences with the poor metabolizer (PM) phenotype representing 2-5% of Caucasian and 13-23% of Oriental populations. In the present study, we identified two new mutations in CYP2C19 in a single Swiss Caucasian...

The 4'-hydroxylation of the S-enantiomer of the anticonvulsant drug mephenytoin exhibits a genetic polymorphism in humans. This polymorphism shows marked interracial heterogeneity, with the poor metabolizer (PM) phenotype representing 2 to 5% of Caucasian and 13 to 23% of Asian populations. Two defective CYP2C19 alleles, CYP2C19*2 and CYP2C19*3, have been described which account for approximate...

CYP2C19 polymorphism is associated with pretreatment drug response prediction, metabolism, and disposition. Pakistan consists of a population comprising of various ethnic groups residing in different regions of the country each claiming diverse ethnic origins. The identification of CYP450 genotypic composition of these populations is therefore necessary to avoid adverse drug reactions in these ...

The amino acid residues affecting the substrate specificity of human cytochrome P450 CYP2C9 and CYP2C19 for their metabolic activities were investigated using chimeras and mutant enzymes, which were constructed by replacing the corresponding residues. Although CYP2C19 showed nearly the same tolbutamide hydroxylase activity as CYP2C9, the activities for the CYP2C19(H99I) mutant and the chimeras ...

Cytochrome P450 2C19 (CYP2C19) is the enzyme responsible for the metabolism of a number of drugs, including anticonvulsants and antidepressants. We have developed a semi-quantitative competitive RT-PCR assay to estimate the degree of expression of the full-length CYP2C19 message. This assay used a known quantity of internally deleted CYP2C19 RNA to quantitate the RT-PCR products of the CYP2C19 ...