Related Experiment Video

Updated: Aug 15, 2026

A Multi-detection Assay for Malaria Transmitting Mosquitoes
09:00

A Multi-detection Assay for Malaria Transmitting Mosquitoes

Published on: February 28, 2015

CYP2D6 phenotypes among Malays in Malaysia

R Ismail1, A Hussein, L K Teh

  • 1Department of Pharmacology, Universiti Sains Malaysia, 16150 Kota Bharu, Kelantan, Malaysia. isrusli@kb.usm.my

Journal of Clinical Pharmacy and Therapeutics
|December 21, 2000
PubMed
Abstract

Insights

The CYP2D6 genetic polymorphism in Malays differs from the Chinese, showing intermediate metabolism. This impacts drug metabolism and disease risk in the Malay population.

Area of Science:

  • Pharmacogenetics
  • Drug Metabolism

Background:

  • The CYP2D6 gene is highly polymorphic and crucial for metabolizing numerous drugs.
  • Previous studies indicated a higher prevalence of CYP2D6 poor metabolism (PM) phenotype in Malays compared to Chinese.
  • Understanding CYP2D6 variations in Malays is important due to intermarriages and potential implications in drug response and environmentally-induced diseases.

Purpose of the Study:

  • To investigate debrisoquine metabolism phenotypes in a cohort of healthy Malay volunteers.
  • To characterize the CYP2D6 genetic polymorphism within the Malay population.

Main Methods:

  • Administration of debrisoquine to 51 healthy Malay participants.
  • Utilizing High-Performance Liquid Chromatography (HPLC) to quantify urinary debrisoquine and 4-hydroxydebrisoquine.
  • Calculation of debrisoquine metabolic ratios (MR) to determine metabolic phenotypes.

Main Results:

  • Debrisoquine metabolic ratios (MR) exhibited wide variability within the study population.
  • Probit analysis identified distinct population subsets based on MR.
  • The frequency distribution of MR showed a rightward shift, less pronounced than observed in the Chinese population, with 2 poor metabolizers and 1 ultra-rapid metabolizer identified.

Conclusions:

  • The debrisoquine metabolic profile in Malays is genetically distinct from that of the Chinese population.
  • Malay individuals appear to possess an intermediate metabolic profile between Europeans and Chinese concerning CYP2D6 polymorphism.
  • Further research comparing CYP2D6 genotypes across related ethnic groups is recommended to elucidate these pharmacogenetic differences.

More Related Videos

Mass Spectrometry and Luminogenic-based Approaches to Characterize Phase I Metabolic Competency of In Vitro Cell Cultures10:44

Mass Spectrometry and Luminogenic-based Approaches to Characterize Phase I Metabolic Competency of In Vitro Cell Cultures

Published on: March 28, 2017

Midface Hypoplasia and Cranial Base Morphology in Syndromic Craniosynostosis: A Comparative Analysis Study Using a Predictive Regression Model08:03

Midface Hypoplasia and Cranial Base Morphology in Syndromic Craniosynostosis: A Comparative Analysis Study Using a Predictive Regression Model

Published on: November 4, 2025

Related Concept Videos

Pedigree Analysis01:35

Pedigree Analysis

Overview
Background and Environment Affect Phenotype02:27

Background and Environment Affect Phenotype

Although the genetic makeup of an organism plays a major role in determining the phenotype, there are also several environmental factors, such as temperature, oxygen availability, presence of mutagens, that can alter an organism’s phenotype.
An example of how genetic background affects phenotype can be seen in horses. The Extension gene in horses is responsible for their coat color. A wild-type gene (EE) produces black pigment in the coat, while a mutant gene (ee) produces red pigment. A...
Principles of Pharmacogenetics: Types of Genetic Variants01:27

Principles of Pharmacogenetics: Types of Genetic Variants

The human genome is over 99.9% identical between individuals, yet genetic differences exist at millions of bases. The human genome contains approximately 3 million variant positions per individual, many of which are heterozygous, contributing to genetic diversity and individual traits. Genetic variations include single-nucleotide polymorphisms (SNPs), insertions, deletions, and copy number variations (CNVs).SNPs, the most common variation, involve single-base changes in DNA. These can be...
Pharmacogenetic Phenotypes: Alterations in Pharmacokinetics, Drug Targets and Biologic Milieu01:29

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 Metabolism: Overview01:27

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 Phase I Enzymes: Cytochrome P450 Isozymes01:28

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,...