HLA-DQ2 (Human Leukocyte Antigen DQ2)

Overview

HLA-DQ2 is a haplotype consisting of the genes HLA-DQA1*05 and HLA-DQB1*02 and is the strongest genetic risk factor for Celiac Disease (gluten intolerance). Approximately 90% of all Celiac patients carry this haplotype.

📍 Position
6p21.32 (Chromosome 6)

🏷️ Category
Immune System

Function of HLA-DQ2

HLA-DQ2 is an immune system molecule that presents gluten peptides. In genetically predisposed individuals, these peptides are mistakenly identified as dangerous.

Key Functions:

🎯 Antigen Presentation

Presents gluten peptides to T-helper cells. Normally harmless, but faulty in DQ2 carriers.

⚡ Immune Activation

Triggers an excessive immune response leading to intestinal villi damage (villous atrophy).

⚠️ Pathomechanism: 1. Gluten ingestion → 2. Faulty presentation as “dangerous” → 3. Autoimmune reaction with destruction of intestinal villi

Disease Risk

🚨 High Risk

Celiac Disease (Gluten intolerance)
Dermatitis herpetiformis – skin manifestation
Type 1 Diabetes – additional risk
Autoimmune thyroiditis

✅ Protective Factors

Early diagnosis through screening
Strict gluten-free diet
Regular check-ups
Family education

📊 Statistics: With HLA-DQ2, you have a ~5-6 fold increased risk of Celiac Disease. However: Only 3-5% of carriers actually develop Celiac Disease!

🧬 Genetic Variants

rs2187668
6:32604395

Normal

C

/

Celiac Risk

T

Tag-SNP for HLA-DQB1*02:01
T-allele is strongly associated with Celiac risk (5-6 fold increase)

Risk Allele:
~25-30%

rs7454108
6:32614911

G
Normal

→

T
DQ2 Component

Tag-SNP for HLA-DQA1*05
In combination with rs2187668, it determines the full DQ2.5 risk haplotype

Risk Allele:
~20-25%

Frequency and Risk

HLA-DQ2 Carrier (Europe)

~25-30%

Development of Celiac

~3-5%

💡 Important: Most DQ2 carriers never develop Celiac disease! Additional environmental factors and other genes are required.

Clinical Significance

🩺 Diagnostics

Negative Predictive Value: No DQ2/DQ8 = Celiac is extremely unlikely
Screening: If Celiac is suspected
Risk Assessment: For family members

🎯 Therapy

Lifelong gluten-free diet
Early detection through screening
Follow-up: Antibody monitoring

📚 Data Sources

OMIM: #212750 (Celiac Disease, Susceptibility to)
dbSNP: rs2187668, rs7454108
PubMed: Sollid (2002) – Coeliac disease: dissecting a complex inflammatory disorder
Nature Reviews: Genetics of celiac disease
ClinVar: HLA-DQB1 and celiac risk variants

Last Update: February 2026

Testing and Interpretation

A genetic test can reveal your Celiac risk:

🧪 Result Interpretation

HLA-DQ2 Positive: Increased risk, but not necessarily Celiac disease

HLA-DQ2 Negative: Very low Celiac risk (<1%)

Further Tests: Transglutaminase antibodies, intestinal biopsy if suspected

👨‍👩‍👧‍👦 Particularly important for: Relatives of Celiac patients and those with chronic digestive issues

HLA-DQ2