Hematological Malignancies UBA1 Mutation Testing

UBA1 is an X-linked gene that encodes an E1 enzyme responsible for initiating ubiquitylation. VEXAS syndrome (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) is an adult onset autoinflammatory disease caused by somatic inactivating mutations in UBA1. Patients with VEXAS syndrome develop a spectrum of inflammatory conditions including relapsing polychondritis, Sweet syndrome, polyarteritis nodosa, giant-cell arteritis. In addition, VEXAS syndrome is associated with progressive hematologic abnormalities (macrocytic anemia, thrombocytopenia, thromboembolic diseases) and myelodysplastic syndrome. Clinical Utility:

UBA1 mutation testing in recommended in patients with refractory autoimmune disorders and cytopenias of unknown etiology. UBA1 mutations are diagnostic of VEXAS syndrome in the appropriate clinicopathologic context.

This test is performed by PCR-based Next Generation Sequencing of DNA extracted from formalin fixed paraffin embedded (FFPE) tissue or fresh tissue including peripheral blood and bone marrow.  Exon 3 of UBA1 is sequenced using massively parallel sequencing (next-generation sequencing) with a combination of multiplexed PCR (customized QIAseq Targeted DNA panel) and sequencing on an Illumina platform.  An in-house bioinformatics analysis pipeline has been used that employs multiple established variant calling tools (FreeBayes, MuTect2 and Scalpel) and variant annotation tools.  The genomic variants have been interpreted in accordance with the 2017 guideline recommendations by AMP/ASCO/CAP (PMID: 27993330).  The assay is validated in accordance with the AMP guidelines (PMID: 28341590).

Clinical Specificity:
Interpretation of this test requires clinicopathologic correlation.

• 5-10 mL of blood or bone marrow — yellow (ACD) or purple (EDTA) tube
• Formalin-fixed paraffin-embedded (FFPE) tissue blocks
• 10 unstained slides (4-5 microns)
• Fresh Tissue:
  • Stabilize in Allprotect Tissue Reagent (Qiagen) and ship at room temperature – OR
  • Suspend in sterile culture media (RPMI or DMEM) or non-bacteriostatic normal saline in a sterile container and shipped at room temperature – OR
  • Snap Frozen and shipped on dry ice
• If sending DNA: please send 200ng at a minimum of 10ng/µL (DNA must be extracted in a CLIA-certified laboratory or a laboratory meeting equivalent requirements as determined by the CAP and/or CMS)
• Pathology report MUST accompany sample for interpretation of results.
  
  A REQUISITION FORM MUST ACCOMPANY ALL SAMPLES.  Please include detailed clinical information.

Once per week

14-18 days

• Package and ship specimen to remain cold, but not frozen. 
• Ship via overnight express, using the FedEx priority overnight label provided. 
• Contact Client Services for shipping kits and instructions at (855) 535-1522.

1. Beck DB et al. Somatic Mutations in UBA1 and Severe Adult-Onset Autoinflammatory Disease. N Engl J Med. 2020 Dec 31;383(27):2628-2638. doi: 10.1056/NEJMoa2026834. Epub 2020 Oct 27. PMID: 33108101; PMCID: PMC7847551.
2. Peter C. Grayson, Bhavisha A. Patel, Neal S. Young; VEXAS syndrome. Blood 2021; 137 (26): 3591–3594. doi: https://doi.org/10.1182/blood.2021011455
3. Poulter J et al Novel somatic mutations in UBA1 as a cause of VEXAS syndrome. Blood 2021; 137 (26): 3676–3681. doi: https://doi.org/10.1182/blood.2020010286