What does HLA-DQ2.5 mean for Celiac Disease?

HLA-DQ2.5 is present in ~90-95% of celiac disease patients. However, ~30% of the general population also carries this allele. Positive result indicates genetic susceptibility but NOT diagnosis. If symptoms are present (chronic diarrhea, bloating, malabsorption), consider serological testing (tTG-IgA).

What does HLA-DQ2.5 mean for Type 1 Diabetes?

HLA-DQ2.5 contributes to T1D risk, especially in combination with HLA-DQ8. This is one of many genetic and environmental factors involved.

Learn · Pharmacogenomics

HLA-DQ2.5

Celiac Disease Susceptibility and 1 other association.

Curated from CPIC / guidelines

What is HLA-DQ2.5?

HLA-DQ2.5 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-DQ2.5?

European	14.0%
East Asian	5.0%
African	5.0%
Global	10.0%

Conditions linked to HLA-DQ2.5

Celiac Disease Susceptibility high risk: HLA-DQ2.5 is present in ~90-95% of celiac disease patients. However, ~30% of the general population also carries this allele. Positive result indicates genetic susceptibility but NOT diagnosis. If symptoms are present (chronic diarrhea, bloating, malabsorption), consider serological testing (tTG-IgA).
Evidence: GWAS OR ~7.0; >95% sensitivity for celiac disease · Source: Multiple GWAS studies; ESPGHAN Guidelines · HLA-DQ2.5 frequency: ~25-30% in Northern Europeans, ~5-10% in East Asians.
Type 1 Diabetes Susceptibility moderate risk: HLA-DQ2.5 contributes to T1D risk, especially in combination with HLA-DQ8. This is one of many genetic and environmental factors involved.
Evidence: GWAS OR ~2-3 · Source: T1DGC GWAS; Nature Genetics 2007

How is HLA-DQ2.5 inferred from a consumer DNA file?

Consumer chips do not sequence HLA genes. HLA-DQ2.5 is inferred from the tag SNP rs2187668 (risk allele T), which travels with the HLA allele on the same stretch of chromosome. How reliably it does so (r²) differs by ancestry:

European	0.95
East Asian	0.8
African	0.75
Global	0.85

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.

See whether your DNA file carries the HLA-DQ2.5 tag
Upload your 23andMe, AncestryDNA or WeGene raw file → · Ask G2: “Am I likely to carry HLA-DQ2.5, 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.