Genetic variant

rs2235544 a variant in the DIO1 gene

rs2235544 is a single-letter difference in the DIO1 gene, on chromosome 1. 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 Levothyroxine response. 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 rs2235544 is the catalogue number of one of them, in the DIO1 gene. Which letters you carry there — one copy from each parent — is your genotype.

DIO1 (iodothyronine deiodinase 1): The protein encoded by this gene belongs to the iodothyronine deiodinase family. It catalyzes the activation, as well as the inactivation of thyroid hormone by outer and inner ring deiodination, respectively. The activation reaction involves the conversion of the prohormone thyroxine (3,5,3',5'-tetraiodothyronine, T4), secreted by the thyroid gland, to the bioactive thyroid hormone (3,5,3'-triiodothyronine, T3) by 5'…

Gene description from NCBI Gene

(Published 2008) Researchers noted that reduced fT3/fT4 ratios may be significant, since various bod...

From SNPedia

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 rs2235544, 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
rs2235544
Gene
DIO1
Position (GRCh38)
chr1:53909896
Variant type
snv
Consequence
intron variant
ClinVar classification
drug response

Genome-wide association studies (9)

TraitRisk alleleOR / betaP-valueStudy
Thyroxine levels A β 0.096 6E-197 PubMed
Free thyroxine concentration A OR 0.15 5E-34 PubMed
Thyroid hormone levels A OR 0.13 3E-18 PubMed
Height A β 0.006 1E-13 PubMed
Free T4 levels A β 0.026 4E-13 PubMed
Thyroxine levels C OR 0.1 5E-12 PubMed
Hypothyroidism A β 0.024 5E-11 PubMed
Red blood cell count A β 0.006 6E-9 PubMed
Multiple myeloma (hyperdiploidy) A OR 1.3 6E-7 PubMed

How common the less frequent letter is

gnomAD ALL
0%
1kG AFR
16.3%
1kG ALL
46%
1kG AMR
35.9%
1kG EAS
53.9%
1kG EUR
47.5%
1kG SAS
66.7%

Sources