Acute promyelocytic leukemia (APL);
Fluorescence in situ Hybridization (FISH)
5mL peripheral blood in sodium heparin
3mL bone marrow in sodium heparin
Fixed cytogenetically prepared cells in sterile centrifuge tube with pellet visible in 3:1, Methanol:Acetic Acid
4°C to 25°C during transit, but specimens may be transported on refrigerated gel packs. Do not allow the gel pack to come in contact with the specimen. Do not freeze. Extreme temperatures should be avoided.
Clotted specimen; Specimen exposed to extreme temperature; Anticoagulant toxic to cells; Insufficient number of cells; Improper fixative
In a normal cell, a two orange and two green signal pattern is observed. In an abnormal cell containing the t(15;17), one orange, a one green and a two fusion signal pattern is observed.
Acute promyelocytic leukemia (APL) accounts for 10% of adult myeloid leukemia and is frequently associated with a translocation involving the promyelocytic leukemia (PML) gene at 15q22 and the retinoic acid α-receptor (RARα) gene at 17q21 resulting in fusion of the genes PML and RARA. Although all patients with APL have t(15;17) or a variant of this translocation, conventional cytogenetic methods detect these translocations in only 70–96% of patients at diagnosis. FISH can detect this translocation in either interphase or metaphase cells.