Genetic variant
rs1800440
rs1800440 is a single-letter difference in human DNA, on chromosome 2. 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 rs1800440 is the catalogue number of one of them. Which letters you carry there — one copy from each parent — is your genotype.
We hold only the basic reference record for this variant: its ID and position. Many catalogued variants have never been linked to anything.
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.
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 rs1800440, 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?
- 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
- rs1800440
- Position
- chr2:38070996
Genome-wide association studies (20)
| Trait | Risk allele | OR / beta | P-value | Study |
|---|---|---|---|---|
| Basal cell carcinoma (MTAG) | C | — | 8E-62 | PubMed |
| Height | C | β 0.011 | 4E-42 | PubMed |
| Nevus count or cutaneous melanoma | T | — | 2E-24 | PubMed |
| Basal cell carcinoma | C | OR 0.92 | 1E-21 | PubMed |
| Basal cell carcinoma | C | OR 0.92 | 1E-21 | PubMed |
| Squamous cell carcinoma (MTAG) | C | — | 1E-21 | PubMed |
| Cutaneous melanoma (MTAG) | T | β 0.074 | 3E-16 | PubMed |
| Melanomas of skin, dx or hx (PheCode 172.1) | T | β 0.07 | 1E-15 | PubMed |
| Skin cancer | T | β 0.052 | 1E-15 | PubMed |
| Cutaneous malignant melanoma | T | OR 1.1 | 7E-15 | PubMed |
| Basal cell carcinoma | T | OR 1.08 | 3E-13 | PubMed |
| Skin cancer | C | β 0.09 | 3E-13 | PubMed |
| Frontal fibrosing alopecia | T | OR 1.55 | 2E-12 | PubMed |
| Basal cell carcinoma | C | β 0.099 | 4E-12 | PubMed |
| Keratinocyte cancer (MTAG) | T | OR 1.08 | 5E-12 | PubMed |
| Non-melanoma skin cancer | — | OR 0.91 | 2E-11 | PubMed |
| Frontal fibrosing alopecia | T | OR 1.65 | 2E-11 | PubMed |
| Lung function (FEV1/FVC) | — | — | 3E-11 | PubMed |
| Melanomas of skin (PheCode 172.11) | T | OR 0.12 | 3E-11 | PubMed |
| Melanomas of skin, dx or hx (PheCode 172.1) | T | β 0.066 | 4E-11 | PubMed |
Sources
- dbSNP: rs1800440 — the reference record
- ClinVar — clinical interpretations submitted by laboratories
- SNPedia — community-written summaries
- GWAS Catalog — association studies