A Novel XNA-based Luminex Assay to Detect UBA1 Somatic Mutations Associated with VEXAS Syndrome
Overview
Affiliations
Objectives: Patients with VEXAS syndrome carry mutations of UBA1 gene coding for the E1 enzyme. The three most frequent mutations are p.M41T(122T > C), p.M41V (c.121A > G), and p.M41L (c.121A > C) in codon 41 of exon 3. Currently, sanger sequencing was mainly used to detect these mutations, which has low sensitivity and low throughput. There is a need of high sensitivity, simple and high throughput method to characterize patients with VEXAS syndrome.
Methods: Based on our proprietary XNA technology, we have developed a QClamp® Plex platform to detect eight mutations in a single reaction using the Luminex xMap technology. The assay sensitivity, specificity and precision were subsequently evaluated. Furthermore, the reference interval and clinical sensitivity/specificity were estimated using clinical healthy/positive DNA samples and the sanger sequencing method was used for comparison.
Results: With spiking synthetic mutant DNA in wildtype GM24385 cell line DNA, this assay can detect mutations with a detection limit of variant allele frequency (VAF) at 0.1-5%. Our assay shows 100% concordance with Sanger sequencing results when used for analyzing 15 positive and 19 negative clinical samples.
Conclusions: The QClamps® Plex Mutation Detection Assay is a quicker, simpler, and more sensitive assay that can accurately detect the mutations even at early stages with low mutation frequency.