RUNX1 SEQUENCE ANALYSIS
BACKGROUND: RUNX1, also known as AML1, encodes the runt-related transcription factor 1 (core-binding factor subunit alpha-2). RUNX1 is located on chromosome 21 and comprises 8 exons. Somatic RUNX1 mutations are found in neoplastic cells from approximately 15% of patients with myelodysplastic syndromes (MDS), and approximately 13% of patients with acute myeloid leukemia (AML). In AML subtype FAB M0 the prevalence of RUNX1 mutations is as high are 40% or greater. In contrast to other AML subtypes, mutations in M0 are frequently biallelic, representing over 50% of cases. Mutations are chiefl y distributed throughout exons 3 – 8. Frameshift and in-frame insertions and deletions, missense, nonsense, and splice site mutations have been reported. RUNX1 mutations appear to be associated with an adverse prognosis in MDS and de novo non-M3 AML. In addition, somatic RUNX1 mutations are clonal markers that can support the diagnosis of MDS.
REASONS FOR REFERRAL: Risk stratifi cation of patients with MDS or AML.
METHOD: RUNX1 mutations are detected and characterized by PCR amplifi cation, and direct sequencing of the coding and junctional regions of RUNX1 exons 1 - 8.
LIMITATIONS: The lower limit of detection of the assay is approximately 20% allele proportion. The assay is expected to detect >99% of variants within RUNX1 exons 1 - 8 that are present at an allele proportion of approximately 20% or greater.
REFERENCE INTERVAL: Somatic mutations are reported as mutation detected or mutation not detected. All sequence variations are reported using standard nomenclature. 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: • Chen CY et al, RUNX1 gene mutation in primary myelodysplastic syndrome-the mutation can be detected early at diagnosis or acquired during disease progression and is associated with poor outcome. (2007) British Journal of Haematology 139, 405-14. • Christiansen DH et al, Mutations of AML1 are common in therapy-related myelodysplasia following therapy with alkylating agents and are signifi cantly associated with deletion or loss of chromosome arm 7q and with subsequent leukemic transformation. (2004) Blood 104, 1474-81. • Harada H et al, Implications of somatic mutations in the AML1 gene in radiation-associated and therapy–related myelodysplastic syndrome/acute myeloid leukemia. (2003) Blood 101, 673-80. • Harada H et al, High incidence of somatic mutations in the AML1/RUNX1 gene in myelodysplastic syndrome and low blast percentage myeloid leukemia with myelodysplasia. (2004) Blood 103, 2316-24. • Kuo M-C et al, RUNX1 mutations are frequent in chronic myelomonocytic leukemia and mutations at the C-terminal region might predict acute myeloid leukemia transformation. (2009) Leukemia 23, 1426-31. • Steensma DP et al, Somatic point mutations in RUNX1/CBFA2/AML1 are common in high-risk myelodysplastic syndrome, but not in myelofi brosis with myeloid metaplasia. (2005) European Journal of Haematology 74, 47-53. • Tang J-L et al, AML1/RUNX1 mutations in 470 adult patients with de nove acute myeloid leukemia: prognostic implications and interaction with other gene alterations. (2009) Blood 114, 5352-61.
March 2016