HLA-DQ genotypes relative risks for celiac disease in Arabs: A case-control study

Area of Science:

• Genetics
• Immunology
• Gastroenterology

Background:

• Celiac disease (CD) predisposition is linked to human leukocyte antigen (HLA)-DQ genotypes.
• The specific risk conferred by these genotypes in Saudi Arabia remains largely uncharacterized compared to Western populations.

Purpose of the Study:

• To establish the CD risk gradient associated with various HLA-DQ genotypes in Saudi Arabia.
• To compare HLA-DQ genotypes between symptomatic and asymptomatic CD patients identified through screening.

Main Methods:

• Genotyping of HLA-DQA1 and HLA-DQB1 genes using polymerase chain reaction sequence-specific oligonucleotide probes.
• Analysis of three subject groups: consecutively diagnosed CD children, screening-identified CD children, and healthy controls.

Main Results:

• A CD risk gradient was identified, with the DQ2.5/DQ8 genotype showing a very high risk (OR 46.93).
• Other risk categories included high (homozygous DQ2.5, DQ2.5/DQ2.2), intermediate (heterozygous DQ2.5, DQ8/DQ2.2), low (DQ8, DQ2.2), and very low risk genotypes.
• Heterozygous DQ8 was more prevalent in the screening-identified group than in symptomatic patients.

Conclusions:

• The DQ2.5/DQ8 genotype represents the highest risk factor for developing celiac disease in the Saudi Arabian population.
• Understanding these genotype-specific risks can aid in risk stratification and early detection strategies.