A screening system for detecting genetic risk markers of type 1 diabetes in dried blood spots

Background: Certain alleles among the genes that code for the human leukocyte antigens (HLA) confer susceptibility or resistance to the development of autoimmunity that causes type 1 diabetes (T1D). A number of ongoing diabetes research studies analyze dried blood spots (DBS) from newborn infants for HLA-D alleles to identify higher-risk children as early as possible. A commercially available assay to detect such alleles has recently become available using a dissociation-enhanced lanthanide fluorescence system found in many newborn screening laboratories. Methods: We adapted the system for use with DBS and improved the sample set-up for greater efficiency. We also developed an independent system for data analysis based on a spreadsheet program. These modifications were applied to HLA-DQB1 gene locus (DQB) analysis of 117 newborn DBS, and the results we obtained were compared with independent reference values. Results: Our assay modifications and independent data analysis improved sample throughput and result tabulation. DQB results from the modified assay were consistent with the reference values in all but one sample, which showed a partial match. Conclusions: The modifications described here make this commercially available assay more suitable for high-throughput applications such as newborn screening. Our results show that this system allows highly accurate detection of DQB alleles that influence T1D risk.