Chronic lymphocyctic leukemia (CLL)
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
5 mm^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 and 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
This probe set allows status assessment of the ATM gene region at 11q22.3. In a normal cell with two intact copies of the ATM gene region, a two green signal pattern is observed. In an abnormal cell with a deletion in the ATM gene region, fewer than two green signals are observed.
B-cell chronic lymphocytic leukemia (B-CLL) is the most common leukemia in the elderly population. With conventional cytogenetic (CC) analysis, ~50% of CLL cases show clonal aberrations. Using FISH, the percentage of patients with abnormalities rises to almost 80%, the most frequent being 13q14, ATM, p53 deletions and trisomy 12. Genetic aberrations were found in 36.7% with CC and in 68.4% with FISH. The frequencies of abnormalities are approximately: 13q deletion, 42.1%; trisomy 12, 19.2%; ATM deletion, 17.5%; and TP53 deletion, 8.7%. FISH can detect this abnormality in interphase or metaphase cells.