Genetic variant

rs1142345

rs1142345 is a single-letter difference in human DNA, on chromosome 6. Carrying it does not, on its own, mean you have or will develop any condition.

What is this?

Your DNA is a long sequence of four letters. At a few million positions, people commonly differ by a single letter; each of those positions is called a SNP (“snip”), and rs1142345 is the catalogue number of one of them. Which letters you carry there — one copy from each parent — is your genotype.

rs1142345 is a SNP in the TPMT gene, potentially encoding a variant incapable of detoxifying byprodu...

From SNPedia

Why might it matter?

ClinVar holds no clinical classification for this variant. That is the usual case: most catalogued variants have no known effect on health.

Medicines

Azathioprine toxicity strong
TPMT*3C — reduced thiopurine metabolism, toxicity risk
Mercaptopurine toxicity strong
TPMT*3C — dose reduction needed

Never start, stop or change a medicine because of a genetic result without speaking to the prescriber.

Do I have this variant?

If you have taken a consumer DNA test (23andMe, AncestryDNA and similar), you can download its raw data file and check. Create a free account, upload the file, and this page will show the letters you carry at rs1142345, if your test read this position.

Connect this with your blood results

A gene is a fixed instruction; a blood test shows what your body is doing now. CheckMyBloods reads the two side by side, so a variant can be set against the markers it could plausibly affect.

Blood markers do not diagnose a genetic condition, and a variant does not explain a blood result on its own. Together, with symptoms and family history, they give a clinician context.

What should I do next?

  1. Find out whether you carry it. Reading about a variant says nothing about you until you know your genotype.
  2. Put it in context. Add your blood results, so the variant can be read against what your body is doing.
  3. Ask questions. Dr. Hemsworth, our AI assistant, can explain this variant and your results in plain English.
  4. Take anything that worries you to a professional. A GP or genetic counsellor can order a confirmatory test and interpret it with your history.

This page is general information drawn from public research databases. It cannot diagnose anything, and it is not a substitute for advice from a doctor or genetic counsellor who knows your history.

Technical details

dbSNP ID
rs1142345
Position
chr6:18130687

Genome-wide association studies (4)

TraitRisk alleleOR / betaP-valueStudy
Thiopurine methyltransferase activity in acute lymphoblastic leukemia patients treated with mercaptopurines — OR 7.69 9E-61 PubMed
Liver thiopurine methyltransferase levels — — 4E-16 PubMed
DNA methylation PhenoAge acceleration T OR 1.96 1E-12 PubMed
Elevated alanine aminotransferase and aspartate aminotransferase levels in acute lymphoblastic leukemia C β 0.44 2E-6 PubMed

Sources