Genetic variant

rs1127354 a variant in the ITPA gene

rs1127354 is a single-letter difference in the ITPA gene, on chromosome 20. ClinVar, the public archive of variant interpretations, lists it as drug response: linked to how the body handles certain medicines. It has been reported in connection with Inosine triphosphatase deficiency and peginterferon alfa-2b and ribavirin response - Toxicity. Carrying it does not, on its own, mean you have or will develop any condition.

ClinVar: Drug response
Drug Response
Chromosome 20

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 rs1127354 is the catalogue number of one of them, in the ITPA gene. Which letters you carry there — one copy from each parent — is your genotype.

ITPA (inosine triphosphatase): This gene encodes an inosine triphosphate pyrophosphohydrolase. The encoded protein hydrolyzes inosine triphosphate and deoxyinosine triphosphate to the monophosphate nucleotide and diphosphate. This protein, which is a member of the HAM1 NTPase protein family, is found in the cytoplasm and acts as a homodimer.
Gene description from NCBI Gene

Why might it matter?

ClinVar records this variant as drug response, meaning linked to how the body handles certain medicines. A classification describes the variant, not you: what it means for one person depends on their genotype, their family history and often on other genes and circumstances.

Conditions it has been reported with

Listed in ClinVar submissions for this variant. Being listed is a report of an association, not a statement that the variant causes the condition in any given person.

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 rs1127354, 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.

Upload blood results

What should I do next?

Find out whether you carry it. Reading about a variant says nothing about you until you know your genotype.
Put it in context. Add your blood results, so the variant can be read against what your body is doing.
Ask questions. Dr. Hemsworth, our AI assistant, can explain this variant and your results in plain English.
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: rs1127354
Gene: ITPA
Position (GRCh38): chr20:3213195
Variant type: snv
Consequence: missense variant
ClinVar classification: drug response