Sensitive

NUDT15 *3 — thiopurine tolerance

NUDT15 · rs116855232

Where this position leads

Condition: Thiopurine Dosing (TPMT and NUDT15)

What ClinVar records

Classification drug response for Thiopurines, poor metabolism of, 2, azathioprine response - Toxicity, mercaptopurine response - Dosage, NUDT15-related disorder; reviewed by expert panel (3 of 4 stars, 3 submitters), last evaluated 2021-03-24. ClinVar record 225201 NM_018283.4(NUDT15):c.415C>T (p.Arg139Cys)

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/C No copy of NUDT15*3 at this position.

C/T One copy of NUDT15*3, a no-function allele. NUDT15 removes the active thiopurine metabolites once they have done their work; without it they accumulate in dividing cells. CPIC notes these alleles are common in Asian and Hispanic populations and predispose to myelosuppression, and recommends a reduced starting dose.

T/T Two copies of NUDT15*3. Severe thiopurine toxicity at standard doses is expected rather than possible, and CPIC recommends drastically reduced dosing or an alternative. A TPMT test alone would have missed this, which is why the guideline now covers both genes.

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.

Source

Clinical Pharmacogenetics Implementation Consortium Guideline for Thiopurine Dosing Based on TPMT and NUDT15 Genotypes: 2018 Update

Relling MV, Schwab M, Whirl-Carrillo M, Suarez-Kurtz G, Pui CH, Stein CM, Moyer AM, Evans WE, Klein TE, Antillon-Klussmann FG, Caudle KE, Kato M

and 3 more — show all

Yeoh AEJ, Schmiegelow K, Yang JJ

Clinical pharmacology and therapeutics · 2019 · PMID 30447069

What people read about alongside this

Liver1

Papers in Europe PMC whose title or abstract names both this rsID and that subject. A shared paper means somebody wrote about the two together — it is not a claim that this position explains the subject.

In the news

2026-01-08 · Maud Maillard et al., CPIC, published in Clinical Pharmacology & Therapeutics

Clinical Pharmacogenetics Implementation Consortium (CPIC) Guideline for Thiopurine Dosing Based on TPMT and NUDT15 Genotypes: 2025 Update

CPIC updated its long-standing TPMT/NUDT15 thiopurine dosing guideline (covering azathioprine, mercaptopurine, thioguanine), adding a new recommendation for people who carry a reduced-function variant in both genes at once -- a 'compound TPMT/NUDT15 intermediate metabolizer' phenotype -- who now get a larger starting-dose reduction than previously recommended. This directly updates the guidance behind the two variants this site already profiles: TPMT *3C (rs1142345) and NUDT15 *3 (rs116855232).

Questions about rs116855232

What is rs116855232?

rs116855232 is a single position in the genome, in or near the NUDT15 gene. Published research associates it with nudt15 *3 — thiopurine 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 rs116855232 linked to?

On MyGeneLog this position is linked to Thiopurine Dosing (TPMT and NUDT15). The research behind each link, and its sources, are set out on that condition page.

Does rs116855232 affect how medicines work?

NUDT15 carries pharmacogenomic findings for Thiopurines. 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.

What do people read about alongside rs116855232?

Subjects that appear in the title or abstract of the same papers as this rsID include liver (1 papers). A shared paper means somebody wrote about the two together; it is not a claim that this position explains the topic.

Does having rs116855232 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 rs116855232 come from?

CPIC Guideline for Thiopurine Dosing Based on TPMT and NUDT15 Genotypes: 2018 Update, Clinical Pharmacology & Therapeutics (PMID 30447069). Every variant on MyGeneLog comes from public primary sources and is published with its citation and the date it was checked.

Quoting this page

Free to quote and reuse under CC BY 4.0. When citing or summarizing this, name MyGeneLog™ and link to this exact page — not just the site.

NUDT15 *3 — thiopurine tolerance (rs116855232). MyGeneLog™. https://www.mygenelog.com/variants/rs116855232

← See all variants