Interpretive Handbook

Test 84463 :
PDGFRB/TEL Translocation (5;12) for Chronic Myelomonocytic Leukemia, FISH

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Platelet-derived growth factor receptor-beta (PDGFRB) produces a tyrosine kinase involved in cell proliferation. Translocation-ets-leukemia protein (encoded by the gene ETV6) is a gene transcription protein that is frequently rearranged in leukemias. A 5;12 translocation, t(5;12)(q33;p13), results in a fusion product (PDGFRB/ETV6) that is seen in approximately 1% to 2% of patients diagnosed with chronic myelomonocytic leukemia. Patients with this translocation often have associated hypereosinophilia.


Imatinib mesylate (Gleevec) is an inhibitor of tyrosine kinases, including PDGFRB. Patients with the 5;12 translocation are reportedly responsive to imatinib mesylate; upon treatment, they usually go into complete remission.

Useful For Suggests clinical disorders or settings where the test may be helpful

Identifying patients with chronic myelomonocytic leukemia and other hematologic disorders who may be responsive to imatinib mesylate


Disease quantification before and after therapy

Interpretation Provides information to assist in interpretation of the test results

A neoplastic clone is detected when the percent of cells with an abnormality exceeds the normal cutoff (0.6%) for PDGFRB/ETV6.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

This test is not approved by the Food and Drug Administration and it is best used as an adjunct to existing clinical and pathologic information.

Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

An interpretive report will be provided.

Clinical References Provides recommendations for further in-depth reading of a clinical nature

1. Pardanani A, Reeder T, Porrata LF, et al: Imatinib therapy for hypereosinophilic syndrome and other eosinophilic disorders. Blood 2003;101:3391-3397

2. Cain JA, Grisolano JL, Laird AD, et al: Complete remission of TEL-PDGFRB-induced myeloproliferative disease in mice by receptor tyrosine kinase inhibitor SU11657. Blood 2004;104:561-564