Development of a Multiplex Genotype Test toward More personalized Medicine for the antiplatelet Drug Clopidogrel and Genetic Analysis of human farnesoid X receptor (NR1H4) in a Korean population

Abstract

a Pharmacogenetics is the field to predict the difference of metabolism and reaction of drugs and chemicals from the general population and individuals using genetically analyse. The adverse drug reactions and side effects were due to environmental factors like drug interactions, age of the patient, nutrition, liver and renal function, such as weather and food, As well as genetic variations of drug metabolizing enzymes, transporters and nuclear receptor genes have a significant impact. Genetic polymorphism of the drug metabolism enzyme, transporters and transcription factors were important factor to predict individual differences in drug response. This study includes two distinct contents. The first part was development of a Multiplex Genotype Test toward more personalized medicine for the antiplatelet Drug Clopidogrel The second part was discovered genetic variation of human farnesoid X receptor (NR1H4) in a Korean population

Part 1

In particular, the drugs used for treating cardiovascular diseases, big differences between individuals of drug response. This study had to development of genotyping technique for genetic polymorphisms of genes that effect of cardiovascular therapeutic response. To study the individual reactions of clopidogrel. We have developed a molecular diagnostics based on Snapshot technology. A set of genetic variants known for causing variations in clopidogrel responses was selected, which included CYP2C19*2, *3, *17, CYP2B6*4, *6, *9, CYP3A4*18, CYP3A5*3, MDR1 2677G > T/A, 3435C > T, and P2Y12 H2 (742T > C). The present molecular diagnostic studies provide an accurate, convenient, and fast genotyping method for the detection of multiple variants. This would be helpful for researchers, as well as clinicians, to use genetic information toward more personalized medicine of clopidogrel and other antiplatelet drugs in the future.

Part 2 Farnesoid X receptor (NR1H4) plays important role in lipid and glucose metabolism, as well as regulation of ADME gene. In order to understand the genetic basis for the variation of FXR, the genetic variations of FXR gene were investigated. We sequenced FXR genes by direct sequencing from 50 Korean and 50 Caucasian subjects. A total of 19 genetic variations were found: nine in exons including four novel non-synonymous SNPs of which four were P101T, M201R, R331C and R441Q, as well as other minor alleles with less than 10% frequency. Nineteen variations were selected to characterize linkage disequilibrium (LD) structures at the FXR locus. The linkage disequilibrium analysis and haplotype prediction show the FXR gene in the single LD block in both Korean and Caucasian but different haplotype profiles. The individual difference of FXR protein expression level in human livers ware approximately 4 fold higher than inter-individual variation of FXR expression and association between FXR*1B in human liver. Statistical analysis showed that the FXR protein levels FXR*1 genotype liver was not significantly higher than FXR*1B genotype. Alterations found in FXR SNP and expression level may influence individual variations in drug responses.