Genetic variant

rs1799853 a variant in the CYP2C9 gene

rs1799853 is a single-letter difference in the CYP2C9 gene, on chromosome 10. ClinVar, the public archive of variant interpretations, lists it as likely benign: probably harmless. It has been reported in connection with Warfarin response and Lesinurad response, among others. 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 rs1799853 is the catalogue number of one of them, in the CYP2C9 gene. Which letters you carry there — one copy from each parent — is your genotype.

CYP2C9 (cytochrome P450 family 2 subfamily C member 9): This gene encodes a member of the cytochrome P450 superfamily of enzymes. The cytochrome P450 proteins are monooxygenases which catalyze many reactions involved in drug metabolism and synthesis of cholesterol, steroids and other lipids. This protein localizes to the endoplasmic reticulum and its expression is induced by rifampin.

Gene description from NCBI Gene

rs1799853 is a SNP in the CYP2C9 gene and is linked to poor warfarin metabolism and risk of GI bleed...

From SNPedia

Why might it matter?

ClinVar records this variant as likely benign, meaning probably harmless. 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.

Medicines

Warfarin dose adjustment strong
CYP2C9*2 — reduced metabolism, lower dose needed
Ibuprofen metabolism moderate
CYP2C9*2 — slower NSAID clearance

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 rs1799853, 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
rs1799853
Gene
CYP2C9
Position (GRCh38)
chr10:94942289
Variant type
snv
Consequence
missense variant
ClinVar classification
Likely benign; drug response; other

Genome-wide association studies (1)

TraitRisk alleleOR / betaP-valueStudy
Warfarin maintenance dose — OR 0.54 1E-31 PubMed

How common the less frequent letter is

gnomAD ALL
88.2%
1kG AFR
99.2%
1kG ALL
4.8%
1kG AMR
90.1%
1kG EAS
99.9%
1kG EUR
87.6%
1kG SAS
3.5%

Sources