Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Pharmacogenetics of Phase I Enzymes: Cytochrome P450 Isozymes

Pharmacogenetics of Phase I Enzymes: Cytochrome P450 Isozymes

Cytochrome P450 (CYP450) enzymes are a superfamily of heme-containing monooxygenases that play a pivotal role in Phase I drug metabolism by catalyzing oxidation and reduction reactions.These enzymes transform lipophilic xenobiotics into more hydrophilic metabolites, facilitating subsequent Phase II conjugation and eventual excretion. The CYP450 family is classified into families (e.g., CYP1–CYP3) and subfamilies (e.g., CYP2A, CYP2C), based on amino acid sequence homology.CYP450 isoenzymes,...

Pharmacogenetic Phenotypes: Alterations in Pharmacokinetics, Drug Targets and Biologic Milieu

Pharmacogenetic Phenotypes: Alterations in Pharmacokinetics, Drug Targets and Biologic Milieu

Genetic variations significantly influence drug response through pharmacokinetics, receptor interactions, and biologic milieu modifications. Pharmacokinetic alterations impact drug metabolism and clearance, affecting efficacy and toxicity. Variants in drug-metabolizing enzymes, such as CYP2C9 and CYP2C19, alter drug activation and elimination. For example, CYP2C9 loss-of-function variants require lower warfarin doses to prevent excessive bleeding, while CYP2C19 variants reduce clopidogrel...

Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase

Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase

Genetic polymorphisms in drug targets have emerged as critical determinants of interindividual variability in drug response and toxicity. Pharmacogenomic investigations increasingly focus on identifying these variations to personalize and optimize therapeutic interventions. A drug target may be a receptor, enzyme, or signaling protein involved in pharmacologic responses or disease-related pathways. While early pharmacogenetic studies focused primarily on drug metabolism, current research...

Pharmacogenetics of Phase II Enzymes: N-acetyltransferase, Thiopurine S-methyltransferase, UDP-glucuronosyltransferase

Pharmacogenetics of Phase II Enzymes: N-acetyltransferase, Thiopurine S-methyltransferase, UDP-glucuronosyltransferase

Phase II biotransformation reactions are essential for detoxifying and eliminating xenobiotics, including many pharmaceutical compounds. These reactions typically involve conjugation, the covalent attachment of polar endogenous groups such as glucuronic acid, sulfate, methyl, or acetyl moieties to functional groups introduced during Phase I metabolism. The resulting conjugates are more water-soluble, enabling efficient renal or biliary excretion.The major classes of Phase II enzymes include...

Pharmacogenetics of Drug Metabolism: Overview

Pharmacogenetics of Drug Metabolism: Overview

Genetic polymorphism in drug metabolism is crucial to the inter-individual variability observed in drug responses. Drug metabolism primarily involves the chemical modification of drugs and other xenobiotics to enhance their elimination by increasing their polarity. Two main classes of enzymes mediate this biotransformation process: Phase I enzymes, primarily cytochrome P450s, catalyze oxidation and reduction reactions, while other enzymes, such as esterases, mediate hydrolysis, and Phase II...

Pharmacogenetics of Drug Transporters: P-Glycoprotein and Solute Carrier Transporters

Pharmacogenetics of Drug Transporters: P-Glycoprotein and Solute Carrier Transporters

The pharmacogenetics of drug transporters is increasingly recognized as a critical factor influencing interindividual variability in drug absorption, distribution, and elimination. These membrane-bound proteins regulate drugs' movement across cellular barriers by actively pumping them out (efflux) or facilitating their uptake (influx). Among the major transporter families, ATP-binding cassette (ABC) and solute carrier (SLC) transporters play particularly prominent roles. Genetic polymorphisms...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Vasoactive intestinal Peptide as a diagnostic or prognostic biomarker in multiple sclerosis: A systematic review.

Multiple sclerosis and related disorders·2026

Same author

Autologous and allogeneic haematopoietic cell transplantation in adult patients with Hodgkin lymphoma: recommendations from the EBMT Practice Harmonisation and Guidelines Committee and Lymphoma Working Party.

The Lancet. Haematology·2026

Same author

Endothelial cell damage in patients with acute graft versus host disease receiving treatment with extracorporeal photopheresis.

Frontiers in immunology·2026

Same author

Diagnostic value of HHV-6A/B genotyping in immunocompromised adults.

Journal of clinical microbiology·2026

Same author

Vasoactive intestinal peptide advances chondrogenesis and modulates pathogenic mediators in human osteoarthritis.

Journal of molecular medicine (Berlin, Germany)·2026

Same author

SCID newborn screening: seven-year performance and outcomes including T-cell lymphopenia in Catalonia (Spain).

Frontiers in immunology·2026

Search research articles

Related Experiment Video

Updated: Jul 20, 2026

Targeted Next-generation Sequencing and Bioinformatics Pipeline to Evaluate Genetic Determinants of Constitutional Disease

Targeted Next-generation Sequencing and Bioinformatics Pipeline to Evaluate Genetic Determinants of Constitutional Disease

Published on: April 4, 2018

CYP2C19 polymorphism and risk for essential tremor.

Hortensia Alonso-Navarro¹, Carmen Martínez, Elena García-Martín

¹Department of Medicine-Neurology, Hospital Príncipe de Asturias, Universidad de Alcalá, Alcalá de Henares, Spain.

European Neurology

|September 9, 2006

Summary

The CYP2C19*1/CYP2C19*2 genotype is linked to a higher risk of developing essential tremor (ET). However, this genetic variation does not influence ET onset age or primidone side effects.

More Related Videos

A Method to Study the C924T Polymorphism of the Thromboxane A2 Receptor Gene

A Method to Study the C924T Polymorphism of the Thromboxane A2 Receptor Gene

Published on: April 1, 2019

Related Experiment Videos

Last Updated: Jul 20, 2026

Targeted Next-generation Sequencing and Bioinformatics Pipeline to Evaluate Genetic Determinants of Constitutional Disease

Targeted Next-generation Sequencing and Bioinformatics Pipeline to Evaluate Genetic Determinants of Constitutional Disease

Published on: April 4, 2018

A Method to Study the C924T Polymorphism of the Thromboxane A2 Receptor Gene

A Method to Study the C924T Polymorphism of the Thromboxane A2 Receptor Gene

Published on: April 1, 2019

Area of Science:

Pharmacogenomics
Neurology
Genetics

Background:

Essential tremor (ET) is a common neurological disorder.
Primidone is a frequently prescribed medication for ET, but many patients experience adverse effects.
Genetic factors, including variations in drug-metabolizing enzymes like CYP2C19, may influence ET risk and drug response.

Purpose of the Study:

To investigate the association between CYP2C19 genetic polymorphism and the risk of developing essential tremor.
To determine if CYP2C19 genotype influences the occurrence of acute adverse effects to primidone in ET patients.
To explore the relationship between CYP2C19 variants and specific tremor presentations.

Main Methods:

Genotyping for CYP2C19 alleles (CYP2C19*1 and CYP2C19*2) was performed using allele-specific PCR and RFLP analyses.
DNA was analyzed from 200 patients with essential tremor and 300 healthy controls.
Associations between CYP2C19 genotypes/alleles and ET risk, age at onset, primidone adverse effects, and tremor type were statistically evaluated.

Main Results:

The frequency of the CYP2C19*1/CYP2C19*2 genotype and the CYP2C19*2 allele was significantly higher in ET patients compared to controls.
No significant differences were observed in the age at onset of ET based on CYP2C19 genotype.
The frequencies of the CYP2C19*1/CYP2C19*2 genotype and CYP2C19*2 allele were similar among ET patients experiencing adverse effects, tolerating primidone, and controls, as well as in patients with specific tremor types.

Conclusions:

Heterozygosity for CYP2C19*1/CYP2C19*2 is associated with an increased risk of developing essential tremor.
CYP2C19 genotype does not appear to be a predictor for the age of ET onset.
This genetic variation is not associated with the development of acute primidone side effects or specific tremor localizations (head, voice, tongue, chin).