Title:Role of HLA-DPrs3077 and HLA-DQrs3920 Polymorphisms as Risk
Factors for Type 1 Diabetes Mellitus
Volume: 23
Issue: 6
Author(s): Amany A. Ghazy*
Affiliation:
- Microbiology and Medical Immunology Unit, Department of Pathology, College of Medicine, Jouf University,
Saudi Arabia
Keywords:
T1DM, HLA-D, Prs3077, SNP, HLA-DQ-rs3920SNP, genotype.
Abstract:
Background: Type 1 diabetes mellitus (T1DM) is a chronic disease caused by the
destruction of insulin-producing pancreatic β-cells. During disease progression, inflammatory
insulitis increases the presentation of islet antigens on human leukocyte antigen (HLA) molecules
to T lymphocytes. This complex system plays a pivotal role in cellular immunity. Thus, genetic
variability in HLA can affect the susceptibility to and clinical outcomes of DM.
Aim: This case-control study aimed to assess the role of HLA-DP-rs3077 (A/G) and HLA-DQrs3920
(A/G) polymorphism in T1DM.
Subjects and Methods: This study enrolled 400 individuals: 200 patients with T1DM and 200 ageand
sex-matched healthy controls. Hemoglobin A1C and random, fasting, and postprandial blood
sugar levels were determined for all subjects. Genotypic and allelic distributions of HLA-DPrs3077
(A/G) and HLA-DQrs3920 (A/G) SNPs were determined using real-time polymerase chain reaction
(PCR).
Results: Frequency of the HLA-DPrs3077A allele was high among the diabetic group (91.3%);
however, the difference was non-significant [OR (95% C.I) = 1.422(0.89-2.252), P=0.098]. The
frequency of the HLA-DQrs3920 GG genotype was higher in control than the diabetic group (52.5%
vs.12%), whereas that of the AA genotype was higher in the person with diabetes than in the control
group (34% vs.4%). Individuals carrying the HLA-DQrs3920A allele were 4.5 times more likely to
have T1DM than those carrying the G allele [OR (95% C.I) = 4.510 (3.338- 6.094), P<0.001*]. The
presence of HLA-DPrs3077A and HLA-DQ rs3920A in the same person increases T1DM risk by
3.6 times that of G allele [OR (95%C.I) = 3.608(2.173-5.991), P<0.001*].
Conclusion: HLA-DPrs3077 and HLA-DQrs3920 SNPs have a role in T1DM as the coexistence of
HLA-DPrs3077A and HLA-DQrs3920A alleles increases the risk.
