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HLA DQA1-DQB1 genotypes in Bedouin families with celiac disease
Susan L Neuhausen1, Zvi Weizman, Nicola J Camp
1Department of Medical Informatics, University of Utah, Salt Lake City 84108, USA. susan@genepi.med.utah.edu
Insights
Celiac disease (CD) susceptibility is strongly linked to specific human leukocyte antigen (HLA) genes. This study found HLA-DQA1 DQB1 genotypes associated with CD in Bedouin families mirror those in European populations.
Area of Science:
- Genetics
- Immunology
- Gastroenterology
Background:
- Celiac disease (CD) is an autoimmune disorder with a strong genetic component.
- Human leukocyte antigen (HLA) genes, particularly HLA-DQA1 and DQB1, are key genetic factors in CD susceptibility.
- The primary risk genotypes are HLA-DQA1*05 DQB1*02 (DQ2) and HLA-DQA1*03 DQB1*0302 (DQ8).
Purpose of the Study:
- To investigate the association of HLA-DQA1 and DQB1 genotypes with celiac disease in Bedouin families.
- To compare the genetic risk factors for CD in a Bedouin population with those observed in European populations.
Main Methods:
- DNA samples from nine multiplex and one simplex Bedouin celiac disease families were genotyped for HLA DQA1 and DQB1.
- Transmission disequilibrium testing (TDT) was used to analyze the over-representation of specific HLA genotypes in affected individuals.
Main Results:
- A significant over-representation of the HLA-DQA1*05 DQB1*02 (DQ2) genotype was observed in affected individuals (p = 0.0089).
- The HLA-DQA1*03 DQB1*0302 (DQ8) genotype also showed an over-representation (p = 0.078).
- The distribution of high-risk HLA DQA1 DQB1 genotypes in Bedouin families was similar to that found in Northern and Southern Europeans.
Conclusions:
- The study confirms the strong association between specific HLA-DQA1 DQB1 genotypes and celiac disease in the Bedouin population.
- The findings suggest that the primary genetic risk factors for celiac disease are consistent across different ethnic groups, including Bedouins and Europeans.
Abstract:
Celiac disease (CD) has a strong genetic association with human leukocyte antigens (HLA). The primary susceptibility for CD is HLA-DQA1*05 DQB1*02 (also known as DQ2), with the remainder of cases primarily HLA-DQA1*03 DQB1*03 (also known as DQ8). In a set of nine Bedouin multiplex celiac disease families and one simplex, we genotyped DNA samples at HLA DQA1 and DQB1. Nineteen celiac disease patients had at least one DQA1*05 DQB1*02 genotype (= DQ2), 4 affecteds had the second most common genotype of DQA1*03 DQB1*0302 (= DQ8), 9 were DQ2 and DQ8, and 4 had at least one copy of DQB1*02 without the DQA1*05 genotype. Using transmission disequilibrium testing, we observed a significant over-representation in affecteds of the DQA1*05 DQB1*02 genotype (p = 0.0089), as well as over-representation of the DQA1*03 DQB1*0302 genotype (p = 0.078). The HLA DQA1 DQB1 high-risk genotypes associated with celiac disease are similar in these Bedouin families with CD to what is observed in Northern and Southern Europeans.