CPT® Code 81334

RUNX1 (runt related transcription factor 1) (eg, acute myeloid leukemia, familial platelet disorder with associated myeloid malignancy) gene analysis, targeted sequence analysis (eg, exons 3-8)

The CPT® Code 81334 pertains to the analysis of the RUNX1 gene, which is crucial for understanding certain hematological conditions, particularly acute myeloid leukemia (AML) and familial platelet disorder (FPD) with associated myeloid malignancy. The RUNX1 gene encodes a transcription factor that plays a significant role in the maturation of blood cells, including white blood cells, red blood cells, and platelets. This gene functions by binding to specific DNA regions to activate genes necessary for blood cell development. The RUNX1 protein works in conjunction with another protein known as core binding factor beta (CBFβ), which is produced by the CBFB gene, to form a complex called core binding factor (CBF). Mutations in the RUNX1 gene can lead to severe hematological disorders. One of the most prevalent mutations involves a translocation between chromosome 21 (RUNX1) and chromosome 8 (RUNX1T1 or ETO), resulting in the formation of the RUNX1-ETO fusion protein. This fusion protein binds to DNA but inhibits the activation of genes, thereby obstructing the normal maturation and differentiation of blood cells. Consequently, this leads to an accumulation of abnormal, immature white blood cells, known as myeloid blast cells, which is characteristic of acute myeloid leukemia. The symptoms associated with AML and FPD may include fever, bone pain, fatigue, dyspnea, pale skin, frequent infections, and unusual bruising or bleeding. To perform the RUNX1 gene analysis, a blood or bone marrow sample is collected, which is a separate procedure. The analysis itself employs Bi-directional Sanger sequencing to examine the targeted exons of the RUNX1 gene, specifically exons 3 through 8, to identify any mutations that may be present.