rs1142345
TPMTrs1142345 is a single-nucleotide polymorphism (SNP) in the TPMT gene. Genespiral reads it in the Health & Wellness analysis to describe Thiopurine Sensitivity (TPMT).
- Gene
- TPMT
- Alleles
- C / T
- Genotypes
- TT, CT, CC
- Traits
- 1 trait across 1 analysis
An rsID such as rs1142345 is the reference number dbSNP assigns to one position in the genome where people commonly differ by a single letter. Raw data exports from 23andMe and AncestryDNA list your two alleles at that position as a genotype - for this marker one of TT, CT, CC. The order of the two letters carries no meaning, so CT and its reverse are the same genotype.
Alleles on this page are written on the forward (plus) strand, matching how consumer raw files report them. Other references sometimes describe the same variant on the opposite strand, which swaps A↔T and C↔G - see why the same variant can look different. The associations below are educational summaries of published research; they are not diagnoses, and the effect of any single SNP is usually modest.
Thiopurine Sensitivity (TPMT)
Medication Response · Part of the Health & Wellness analysis
The TPMT*3C variant reduces the enzyme that breaks down thiopurine drugs (azathioprine, 6-mercaptopurine); low activity raises the risk of toxicity.
| Genotype | Association |
|---|---|
| TT | Normal TPMT activity |
| CT | Intermediate activity |
| CC | Low activity — higher toxicity risk |
- Summary
- TPMT genotype predicts how well thiopurine medications are cleared and the risk of dose-related side effects.
- Scientific insights
- 'CC' (low activity) individuals are at higher risk of thiopurine toxicity and usually need much lower doses; 'TT' is normal.
- Lifestyle tips
- Informational only — thiopurine dosing is guided by clinical TPMT testing and a physician, not consumer data.
Check your genotype at rs1142345
Load your raw DNA file and Genespiral looks up rs1142345 along with every other marker in the Health & Wellness analysis. The file is parsed in your browser and never uploaded, so your genotype stays on your device.
- 1. Download your raw data from 23andMe or AncestryDNA.
- 2. Open the analysis below and choose the file.
- 3. Find Thiopurine Sensitivity (TPMT) in your results.
Related
References
Primary databases for this variant. Use them to check allele orientation, population frequencies, and the underlying studies.
- dbSNP entry for rs1142345 - NCBI
- rs1142345 variant page - Ensembl
- rs1142345 summary - SNPedia
- Clinical significance records for rs1142345 - ClinVar
- TPMT gene - NCBI Gene
Genespiral is an educational tool, not a medical service. Genetic associations describe tendencies observed across populations, not certainties for you. Read the full disclaimer.