| Alternative names | Allele | Predicted consequence in patients receiving FU |
DPYD variants |
DPYD*13 | c.1679T>G (rs55886062) | – | - Decreased DPD activity
- Increased toxicity risk
|
DPYD*2A | c.1905+1G>A (rs3918290) | – | - Abolished DPD activity (homozygotes)
- Greatly increased toxicity risk
|
DPYD*9B | c.2846A>T (rs67376798) | – | - Decreased DPD activity
- Increased toxicity risk
|
HapB3 collection of SNPs | c.483+18GG>A, c.680+139G>A, and c.959-51T>C c.1236G>A occurring in complete linkage with c.1129-5923C>G | – | - Modest decrease in DPD
- Increased toxicity risk
|
TYMS variants |
3'-UTR - 6 bp deletion (TTAAAG) (rs34489327; historically rs16430)
| – | Deletion | - Decreased TYMS expression
- Increased FU responsiveness
- Increased risk of toxicity
|
5'-TSER - 28 bp VNTR (2R; 3R) (rs45445694)
- G>C SNP in 2nd repeat of 3R allele (3RC) (rs34743033)
| – | 2R | 2R/2R or 2R/3RC: - Decreased TYMS expression
- Increased FU responsiveness
- Increased risk of toxicity
|
– | 3RC | 3RC/3RC or 2R/3RC: - Decreased TYMS expression
- Increased FU responsiveness
- Increased risk of toxicity
|