2 466316223221Reads by AI crawlersClaude6ChatGPT3Google · Gemini0Perplexity1Meta AI6Microsoft · Copilot2Amazon2Apple3China (ByteDance, Huawei, Baidu…)2ByteDance (Doubao)2Others21Total46Counted by the name each crawler declares; requests found to be impersonating one are left out. Google · Gemini includes Googlebot, the search crawler whose index Google also uses for its AI features. Other search engines and bots are under Others.
Classificationdrug response for Dihydropyrimidine dehydrogenase deficiency, Fluorouracil response, Hirschsprung disease, susceptibility to, 1, tegafur response - Toxicity, fluorouracil response - Toxicity and 24 more; reviewed by expert panel (3 of 4 stars, 31 submitters), last evaluated 2021-05-24.
ClinVar record 432NM_000110.4(DPYD):c.1905+1G>A
ClassificationPathogenic/Likely pathogenic for Dihydropyrimidine dehydrogenase deficiency; criteria provided, multiple submitters, no conflicts (2 of 4 stars, 4 submitters), last evaluated 2026-05-30.
ClinVar record 2429124NM_000110.4(DPYD):c.1905+1G>C
What this is ClinVar's aggregate record for this position (as of its 2026-10-19 release), not a result about you. A classification describes the variant against the condition named, as laboratories submitted it. Whether a person carries this variant, and what that would mean for them, is a question for a clinical test and a genetic counsellor.
What each result means
C/CNo copy of DPYD*2A at this position.
C/TOne copy of DPYD*2A, which destroys the splice site and leaves no enzyme from that copy. DPD clears about 80% of a dose of fluorouracil or capecitabine; with one working copy, clearance is roughly halved and CPIC recommends starting at a reduced dose with titration.
T/TTwo copies of DPYD*2A — essentially no DPD activity. Standard fluoropyrimidine doses have caused fatal toxicity in this situation, and CPIC recommends avoiding these drugs. Extremely rare, and one of the strongest reasons pre-treatment DPYD testing exists at all.
This is a pharmacogenomic result with a published dosing guideline behind it. Tell a prescriber or pharmacist rather than acting on it — and never stop or change a prescribed medicine on the strength of a genotype.
Clinical pharmacology and therapeutics · 2018 · PMID 29152729
Questions about rs3918290
What is rs3918290?
rs3918290 is a single position in the genome, in or near the DPYD gene. Published research associates it with dpyd *2a — fluoropyrimidine tolerance. A single variant does not decide an outcome — it shifts a probability, and for most common variants the shift is small.
What conditions is rs3918290 linked to?
On MyGeneLog this position is linked to Fluoropyrimidine Dosing (DPYD). The research behind each link, and its sources, are set out on that condition page.
Does rs3918290 affect how medicines work?
DPYD carries pharmacogenomic findings for Fluoropyrimidines. That is educational information, not a prescription or a dosing guide. Any decision to start, stop or change a medicine belongs with the clinician or pharmacist managing your treatment.
Does having rs3918290 mean I will get this?
No. Common variants like this one move a probability slightly and, on their own, rarely decide anything about one person. Nothing on this page is a diagnosis, and health decisions should be made with a clinician who can see your whole picture.
Where does the information about rs3918290 come from?
CPIC Guideline for Dihydropyrimidine Dehydrogenase Genotype and Fluoropyrimidine Dosing: 2017 Update, Clinical Pharmacology & Therapeutics (PMID 29152729). Every variant on MyGeneLog comes from public primary sources and is published with its citation and the date it was checked.
2 466316223221Reads by AI crawlersClaude6ChatGPT3Google · Gemini0Perplexity1Meta AI6Microsoft · Copilot2Amazon2Apple3China (ByteDance, Huawei, Baidu…)2ByteDance (Doubao)2Others21Total46Counted by the name each crawler declares; requests found to be impersonating one are left out. Google · Gemini includes Googlebot, the search crawler whose index Google also uses for its AI features. Other search engines and bots are under Others.
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