ASXL1 MUTATION ANALYSIS BloodCenter of Wisconsin Diagnostic Laboratories off ers ASXL1 mutation analysis BACKGROUND: Somatic mutations in the ASXL1 gene have been described in all types of myeloid malignancies including acute myeloid leukemia (AML)1-3, myeloproliferative neoplasms (MPN)4, myelodysplastic syndromes (MDS)5,6, chronic myelomonocytic leukemia (CMML)7, and rarely in juvenile myelomonocytic leukemia (JMML)8. Most ASXL1 mutations occur in exon 13 (referred to as exon 12 in many publications) and are frequently frameshift or nonsense mutations that result in C-terminal truncation of the protein upstream of the plant homeodomain fi nger region. Around 6.5% of de novo and ~30% of secondary AML contain ASXL1 mutations1. ASXL1 mutations have been reported to have prognostic value in certain subgroups of AML patients: Among patients with intermediate-risk karyotypes, ASXL1 mutations have been associated with shorter overall and event free survival9; among patients with normal karyotypes, ASXL1 mutations have been associated with inferior survival in European LeukemiaNet (ELN) “favorable” patients (mutated CEBPA and/or mutated NPM1 without FLT3-ITD) but not in ELN Intermediate-I patients2. ASXL1 mutations are more frequent in males, elderly patients, and patients with a history of MDS9. ASXL1 mutations occur in ~16% of MDS cases, 34.5% of primary myelofi brosis cases, and ~45% of CMML cases while being rare in polycythemia vera and essential thrombocythemia1,4,5-7. ASXL1 mutations are associated with poor prognosis typifi ed by aggressive disease, shorter overall survival1,4,9, elevated International Prognostic Scoring System risk group6, and transformation to AML5-7. REASONS FOR REFERRAL: Risk stratifi cation and possible treatment decisions in patients with myeloid malignancies. METHOD: The assay is performed by PCR amplifi cation and bidirectional sequencing of the coding regions and intron-exon junctions of exon 13 (also referred to as exon 12 in many publications) of the ASXL1 gene. If needed, fragment analysis is performed to confi rm length mutations. LIMITATIONS: The lower limit of detection of the assay is approximately 20% (allele proportion). REFERENCE INTERVAL: Mutations are reported as mutation detected or mutation not detected using standard nomenclature. Polymorphisms are not reported but are available upon request. SPECIMEN REQUIREMENTS: 3-5 ml EDTA (lavender top) whole blood or 2-5 ml EDTA bone marrow. SHIPPING REQUIREMENTS: Place the room temperature specimen and requisition in plastic bags, seal and insert in a Styrofoam container. Seal the Styrofoam container, place in a sturdy cardboard box and tape securely. Ship the package in compliance with your overnight carrier guidelines. Address package to: Client Services/Molecular Oncology Laboratory BloodCenter of Wisconsin 638 N. 18th Street Milwaukee, WI 53233 800-245-3117, ext. 6250 TURNAROUND TIME: 5-10 days CPT CODES: 81479 REFERENCES: 1. Gelsi-Boyer V et al. J Hematol Oncol 2012;5:12. 2. Metzeler KH et al. Blood 2011;118:6920-6929. 3. Pratcorona M et al. Haematolgica 2012;97:388-392. 4. Brecqueville M et al. Genes Chromosomes Cancer 2012; 51:743-755. 5. Thol F, et al. J Clin Oncol 2011;29:2499-506. 6. Bejar R et al. N Engl J Med 2011;364:2496-2506. 7. Gelsi-Boyer V et al. Br J Haematol 2010;151:365-375. 8. Sugimoto Y et al. Br J Haematol 2010;150:83-87. 9. Schnittger S et al. Leukemia 2013;27:82-91. March 2016.