Application of Molecular Biotechnology in Pharmacogenetics: Genetic Variants as Predictors of Drug Response

Abstract

Pharmacogenetics represents a pivotal integration of molecular biotechnology and clinical pharmacology, aiming to elucidate the genetic basis of interindividual variability in drug response. As the paradigm of medical treatment shifts from a generalized approach to precision medicine, understanding how genetic variants predict therapeutic efficacy and adverse drug reactions (ADRs) is paramount. This narrative literature review synthesizes the molecular and genetic foundations of pharmacogenetics, emphasizing the role of single-nucleotide polymorphisms (SNPs), structural variations, and gene expression profiles in modulating pharmacokinetic and pharmacodynamic pathways. Central to this transition are advanced molecular biotechnology techniques, including real-time quantitative PCR, next-generation sequencing (NGS), microarray analysis, and emerging CRISPR-based functional screens, which have democratized genomic data acquisition. We comprehensively review major actionable gene-drug pairs, such as CYP2D6 (antidepressants, tamoxifen), CYP2C19 (clopidogrel), CYP2C9 and VKORC1 (warfarin), HLA-B variants (abacavir, carbamazepine), TPMT/NUDT15 (thiopurines), DPYD (fluoropyrimidines), and SLCO1B1 (statins), outlining their clinical translation via CPIC and DPWG guidelines. Despite profound scientific advancements, clinical implementation faces multifaceted challenges, including genetic diversity across underrepresented populations, interpreting rare variants, hybrid alleles in complex genomic loci, ethical considerations, and the cost-effectiveness of preemptive testing. Finally, we discuss the integration of high-throughput sequencing, artificial intelligence, and machine learning into clinical decision-support systems, projecting future perspectives for precision medicine. By leveraging sophisticated molecular biotechnologies, pharmacogenetics stands to significantly enhance therapeutic safety and efficacy, realizing the promise of individualized patient care.