TY - JOUR T1 - High Accuracy and Significant Savings Using Tag-SNP Genotyping to Determine <em>HLA-B*27</em> Status JF - The Journal of Rheumatology JO - J Rheumatol SP - 962 LP - 963 DO - 10.3899/jrheum.161095 VL - 44 IS - 6 AU - JOSH LEHR AU - PROTON RAHMAN AU - DARREN D. O’RIELLY Y1 - 2017/06/01 UR - http://www.jrheum.org/content/44/6/962.2.abstract N2 - To the Editor:Axial spondyloarthritis (axSpA) is characterized by inflammatory back pain, spinal ankylosis, peripheral arthritis, and extraarticular manifestations1. HLA-B*27 status is particularly helpful in diagnosis because the combination of severe sacroiliitis on magnetic resonance imaging with HLA-B*27 positivity is an excellent predictor of disease outcome2. However, because of inherent challenges associated with multiallelic genetic testing, clinical tests evaluate the entire HLA-B locus using commercially available kits. Consequently, the clinical value of the HLA-B locus test as a tool for primary care physicians is constrained, primarily because of cost. A large genome-wide association study demonstrated that a tag-single-nucleotide polymorphism (SNP) can be used to determine HLA-B*27 status in whites3. The objective of our study was to assess the analytical validity and economic effect of using a HLA-B*27 tag-SNP assay compared with an HLA-B locus test in a clinical genetics laboratory. The ethics committee from Memorial University approved the study. Patient consent was obtained.The study cohort consisted of 1000 consecutive patient samples received by the clinical genetics laboratory at Eastern Health to determine the HLA-B*27 genotyping status. Institutional … Address correspondence to D.D. O’Rielly, Faculty of Medicine, Suite 3M500, Craig L. Dobbin Genetics Research Centre, Memorial University, St. John’s, Newfoundland and Labrador A1B 3V6, Canada. E-mail: darren.orielly{at}med.mun.ca ER -