F TEL AML1
Pediatric acute lymphoblastic leukemia, Acute lymphoblastic leukemia (ALL)
Fluorescence in situ Hybridization (FISH)
2.0 mL (min. 1.0 mL) peripheral blood in sodium heparin preferred, EDTA accepted
1.0 mL (min. 0.5 mL) bone marrow in sodium heparin preferred, EDTA accepted
5mm^3 fresh tissue or 3.0 mL (min 2.0 mL) FNA in MPLN RPMI media
Whole blood and bone marrow, ship ambient
Fresh tissue or FNA ship in a Styrofoam container with a cool/refrigerated pack (Do not allow cool pack to directly contact sample)
Clotted specimen; Specimen exposed to extreme temperature; Anticoagulant toxic to cells; Insufficient number of cells
A normal cell contains two orange (AML1), two green (TEL) signal pattern. An abnormal cell containing the t(12;21) has a signaml pattern of one green, one large orange, and two fused orange/green (yellow) signals.
TEL/AML1 (also known as ETV6/RUNX1) translocation is the most frequent genetic abnormality in childhood B-acute lymphoblastic leukemia (ALL) found in 20-30% of cases. The t(12;21) involves the TEL gene on 12p13 and the AML1 gene on 21q22. Cytogenetically, the t(12;21) is a subtle abnormality and not easily detected with conventional cytogenetic banding techniques. FISH can detect this translocation in either interphase or metaphase cells.