HLA-DRB1*04
Rheumatoid Arthritis Susceptibility.
What is HLA-DRB1*04?
HLA-DRB1*04 is a variant of a human leukocyte antigen (HLA) gene, the system the immune system uses to present fragments of proteins — including drugs bound to proteins — to T cells. Particular HLA alleles bind particular drugs, which is why carrying one can turn an ordinarily safe medicine into a severe immune reaction, and why some alleles track autoimmune conditions.
How common is HLA-DRB1*04?
| European | 15.0% |
|---|---|
| East Asian | 10.0% |
| African | 5.0% |
| Global | 10.0% |
Conditions linked to HLA-DRB1*04
- Rheumatoid Arthritis Susceptibility moderate risk
- HLA-DRB1*04 (shared epitope) is a major genetic risk factor for rheumatoid arthritis, especially anti-CCP positive RA. If experiencing symmetric joint pain, morning stiffness, or joint swelling, consult a rheumatologist. Early diagnosis and treatment significantly improve outcomes.
Evidence: GWAS OR ~3-5 for anti-CCP+ RA · Source: WTCCC; Raychaudhuri et al. Nature Genetics 2012 · The 'shared epitope' hypothesis: specific amino acid sequences in HLA-DRB1 (positions 70-74) confer RA risk.
How is HLA-DRB1*04 inferred from a consumer DNA file?
Consumer chips do not sequence HLA genes. HLA-DRB1*04 is inferred from the tag SNP rs660895 (risk allele G), which travels with the HLA allele on the same stretch of chromosome. How reliably it does so (r²) differs by ancestry:
| European | 0.8 |
|---|---|
| East Asian | 0.75 |
| African | 0.65 |
| Global | 0.75 |
A tag-SNP call is a probability, not a laboratory HLA type. A positive result that would change a prescription should be confirmed by clinical HLA typing.
Upload your 23andMe, AncestryDNA or WeGene raw file → · Ask G2: “Am I likely to carry HLA-DRB1*04, and what should I tell my doctor?”
Genetic associations describe risk across populations, not a diagnosis for any one person. Most variants shift risk modestly and act alongside lifestyle, environment and other genes. Consumer DNA chips do not read every position and can be wrong at any single one. For general education only; talk to a clinician or genetic counsellor before acting on anything here, and never change a prescribed medicine without your prescriber.