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Updated: Jun 10, 2026

Multi-Gene Single Nucleotide Polymorphism Detection in Gastric Cancer Based on Ion Semiconductor Sequencing Platform
Published on: May 10, 2024
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.
Background:
Encephalopathy is a rare drug toxicity of fluorouracil therapy. Toxicity from fluorouracil therapy is known to be associated with the individual genetic background of the enzymes, thymidylate synthase and dihydropyrimidine dehydrogenase.
Methods:
Two patients with advanced gastric cancer and metastatic pancreatic cancer who received 5-fluorouracil-based chemotherapy presented with acute mental change and hyperammonemia. To evaluate the genetic background of the fluorouracil-associated hyperammonemic encephalopathy, analysis of the polymorphisms of the TYMS, DPYD and MTHFR genes was performed.
Results:
The patients revealed to be TYMS suppressors showing homogenous deletion of 6 bp in the 3'-UTR and 3RC/3RC genotype in the promoter enhancer region (TSER), respectively.
Conclusion:
Genetic polymorphisms of the TYMS gene would contribute to the 5-fluorouracil-associated hyperammonemic encephalopathy. The prospective validation of the clinical implication of TYMS gene polymorphisms is warranted.
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