#56-OR
HLA AND SNP CO-AMPLIFICATION AND MULTIPLEX ASSAYS FOR ESTIMATING TYPE 1 DIABETES GENETIC RISK.
Priscilla V. Moonsamy, BA, Alan Blair, BS, Persia Bonella, BS, Bryan Hoglund, BS, Paul Sali, BS, Aaliyah Hodge, BS, Jeff Post, BA, Janelle Noble, BA, PhD, Teodorica Bugawan, BS and Henry Erlich, BS,PhD. Alameda CA, USA, Roche Molecular Systems, 94501, Human Genetics and Oakland CA, USA, Children
s Hospital Oakland Research Institute, Human Genetics.
The HLA region accounts for over 50% of the genetic risk for Type I diabetes. Most of the risk is attributed to alleles at the DRB1, DQA1 and DQB1 loci. In addition, non-HLA markers (SNPs) have shown small but incremental risk susceptibility. For estimating an individual’s risk for T1D, three genotyping assays have been developed: (1) a DQA1+DQB1 co-amplification, (2) a DPA1+DPB1 co-amplification, and (3) a DRB1, Insulin (-23 Hph1 SNP), and CTLA-4 (T17A SNP) multiplex (T1D) assay, followed by a DRB1 subtyping assay. The linear array technology utilizes biotinylated primers and immobilized BSA-SSO probes (4 primers and 52 probes for DQA1+DQB1, 4 primers and 48 probes for DPA1+DPB1, 9 primers and 8 probes for DRB1 + 4 primers and 4 probes for the SNPs (T1D), and 7 primers and 31 probes for DRB1 subtyping.) Specific hybridization is detected by a colorimetric reaction using SA-HRP and the chromogenic substrate TMB (Tetramethylbenzidine). This typing system will be used for the Type 1 Diabetes Genetics Consortium (T1DGC) samples. Excluding sample preparation, each assay can be completed in less than 4.5 hours. This assay format uses less reagents, and can be semi-automated with the BeeBlot® hybridization instrument. With the creation of the StripScan software, linear arrays can be imaged and imported into the SCORE program for automated allele and SNP assignment. The relatively high level of resolution and ease of use makes these assays suitable for participating laboratories to generate data from a large and diverse group of human populations.