Pharmacogenetics, Pharmacogenomics, and Personalized Medicine

  • Gerard Marshall Raj


The genetic heterogeneity existing in individuals can be responsible for the differential therapeutic and/or adverse outcomes to drugs observed across different patient groups. Though the terms pharmacogenetics and pharmacogenomics are often used interchangeably, there is a thin-yet-tough line of demarcation. Pharmacogenetics refers to how variations in a single gene (monogenetic variants) affect the response to a drug. Whereas, pharmacogenomics is a broader “multifactorial” term, which studies how the entire spectrum of genes (a larger number of variants or the whole genome) can influence drug response pertaining to both efficacy and safety. The science about who will benefit from a particular drug and who will not is referred to as personalized medicine – which deals about the clinical application of pharmacogenetics and pharmacogenomics. Owing to the misinterpretation that was surrounding the usage of the term personalized medicine, an alternative term precision medicine came into vogue. Treatment and preventive approaches that would be effective for patients based on their genetic, environmental, and lifestyle factors were put under the umbrella term of precision medicine. Nearly 90% of the human genetic polymorphisms are single-nucleotide polymorphisms (SNPs). These SNPs can occur in the coding or noncoding regions; the coding SNPs can be either synonymous (no change in the amino acid) or nonsynonymous (change in the amino acid). Pharmacogenetics can be involved at the level of both pharmacokinetics (variation in the drug metabolizing enzymes or transporters) and pharmacodynamics (variation in the drug targets). The pharmacogenetic studies range from the specific candidate gene approach, through haplotype analysis and to the broader genome-wide association studies (GWAS). The application of pharmacogenomics in real patient-life settings is supported by organizations like the Clinical Pharmacogenetics Implementation Consortium (CPIC) and open-source databases like the Pharmacogenomics Knowledgebase (PharmGKB).


Pharmacogenetics Pharmacogenomics Single-nucleotide polymorphism (SNP) Genetic variation Precision medicine 


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© Springer Nature Singapore Pte Ltd. 2019

Authors and Affiliations

  • Gerard Marshall Raj
    • 1
  1. 1.Department of PharmacologySri Venkateshwaraa Medical College Hospital and Research Centre (SVMCH & RC)PuducherryIndia

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