PharmacogenomicsEvidence 1A

rs3918290 · DPYD

Risk allele: A

Risk-Allele Phenotype

DPYD *2A variant (IVS14+1G>A); severe dihydropyrimidine dehydrogenase deficiency (~5% activity); 5-FU contraindicated - causes life-threatening toxicity (mucositis, myelosuppression, neurotoxicity, fatal reactions).

Reference-Allele Phenotype

Normal 5-FU metabolism and clearance.

Evidence Level

1A — Strong — multiple high-quality studies See methodology for how we grade evidence.

Cross-References

dbSNP — rs3918290
ClinVar — search rs3918290
NCBI Gene — DPYD
PharmGKB — rs3918290

Informational only

This page summarizes population-level evidence about a genetic variant. It is not a diagnosis. Your individual risk depends on your full genome, lifestyle, environment, and family history. Consult a healthcare provider for personalized medical advice.

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