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Genetic polymorphisms associated with 5-Fluorouracil-induced neurotoxicity
Suk-Ran Kim1, Chang-Hun Park, Silvia Park
1Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Genetic variations in the thymidylate synthase (TYMS) gene can cause fluorouracil-induced hyperammonemic encephalopathy. Further research is needed to confirm the clinical significance of these TYMS gene polymorphisms.
Area of Science:
- Oncology
- Pharmacogenomics
- Neuroscience
Background:
- Fluorouracil (5-FU) chemotherapy can cause rare but severe drug toxicity, including encephalopathy.
- This toxicity is often linked to an individual's genetic makeup affecting key enzymes like thymidylate synthase (TYMS) and dihydropyrimidine dehydrogenase (DPYD).
Observation:
- Two patients undergoing 5-FU-based chemotherapy for advanced cancers developed acute mental changes and hyperammonemia.
- Genetic analysis was performed to investigate the role of TYMS, DPYD, and MTHFR gene polymorphisms in this adverse event.
Findings:
- Both patients exhibited genetic profiles indicating TYMS suppression.
- Specifically, they had a 6 bp deletion in the 3'-UTR and a 3RC/3RC genotype in the promoter enhancer region (TSER) of the TYMS gene.
Implications:
- Polymorphisms within the TYMS gene are implicated as a contributing factor to 5-FU-associated hyperammonemic encephalopathy.
- Prospective studies are necessary to validate the clinical impact of TYMS gene variations on patient outcomes.
Related Concept Videos
Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase
Pharmacogenetic Phenotypes: Alterations in Pharmacokinetics, Drug Targets and Biologic Milieu
Pharmacogenetics of Phase II Enzymes: N-acetyltransferase, Thiopurine S-methyltransferase, UDP-glucuronosyltransferase
Principles of Pharmacogenetics: Types of Genetic Variants
Drug toxicity: Idiosyncratic Reactions
Pharmacogenetics of Drug Transporters: P-Glycoprotein and Solute Carrier Transporters
