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Candidate Gene Testing in Clinical Cohort Studies with Multiplexed Genotyping and Mass Spectrometry
Published on: June 21, 2018
Two single nucleotide polymorphisms identify the highest-risk diabetes HLA genotype: potential for rapid screening
Jennifer M Barker1, Taylor M Triolo, Theresa A Aly
1Barbara Davis Center for Childhood Diabetes, University of Coloradoat Denver, Colorado, USA. jennifer.barker@uchsc.edu
Diabetes
|August 13, 2008
Summary
A new two-single nucleotide polymorphism (SNP) test rapidly and affordably identifies individuals with the highest genetic risk for type 1 diabetes (T1D). This screening method accurately detects the DR3/4-DQ8 genotype, crucial for early intervention strategies.
Area of Science:
- Immunogenetics
- Molecular Diagnostics
- Diabetes Research
Background:
- The human leukocyte antigen (HLA) genotype DRB1*0301-DQA1*0501-DQB1*0201/DRB1*04-DQA1*0301-DQB1*0302 (DR3/4-DQ8) confers the highest risk for type 1 diabetes (T1D).
- Accurate identification of individuals with this high-risk genotype is essential for T1D prevention and management strategies.
- Existing methods for HLA genotyping can be time-consuming and expensive, limiting widespread screening.
Purpose of the Study:
- To develop an inexpensive and rapid screening test for the high-risk DR3/4-DQ8 genotype.
- To utilize two specific single nucleotide polymorphisms (SNPs) for efficient identification of the DR3/4-DQ8 genotype.
Main Methods:
- Two single nucleotide polymorphisms (SNPs), rs2040410 and rs7454108, were selected based on their association with DR3-DQB1*0201 and DR4-DQB1*0302.
- The association of these SNPs with HLA genotypes was correlated using publicly available data from 5,019 subjects (Type 1 Diabetes Genetic Consortium).
- SNP analysis was performed on 143 HLA-typed children from the Diabetes Autoimmunity Study of the Young (DAISY) using Taqman probes and restriction digest analysis.
Main Results:
- A combinatorial rule using the two SNPs accurately identified the presence or absence of the DR3/4-DQ8 genotype.
- In the Type 1 Diabetes Genetic Consortium cohort, the test demonstrated 98.5% sensitivity and 99.7% specificity for DR3/4-DQ8.
- In the DAISY cohort, the test achieved 100% sensitivity and 100% specificity, indicating high accuracy across different populations.
Conclusions:
- A simple two-SNP screening test provides a time- and cost-effective method for identifying the highest-risk heterozygous genotype for type 1 diabetes.
- This rapid screening approach can facilitate early identification of at-risk individuals, enabling timely intervention and personalized diabetes management.
- The high sensitivity and specificity of this SNP-based test support its potential for widespread application in T1D risk assessment.
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