Test Directory

• IGH, 14q32.3
• BCL2, 18q21.33-q22.1

B-cell leukemia/lymphoma 2 (BCL2) blocks apoptosis and maintains long-term immune responsiveness including B-cell memory. The most frequent non-random chromosome rearrangement in non-Hodgkin lymphoma (NHL) of B-cell type is t(14;18)(q32;q21), which is found in approximately 50–85% of follicular lymphomas, 15–30% of diffuse large B-cell lymphomas, and occasionally in other histological subtypes of NHL. Molecular studies of this translocation have disclosed a juxtaposition of BCL2 gene in 18q21.3 with immunoglobulin heavy chain (IGH) gene locus at 14q32.33. Consequently, the BCL2 gene is subjected to the control of the IGH EA enhancer leading to the over expression of the anti-apoptotic protein BCL2. FISH can detect this translocation in either interphase or metaphase cells.

Specimen Types: Leukemic Blood or Bone Marrow

Preferred Collection Container: Green Top (Sodium Heparin)

Alternate Collection Container: Lavendar Top (EDTA)

Desired Specimen Volume: 3 - 5 mL

Minimum Acceptable Volume: 1 mL

• Lithium heparin is not acceptable.
• Specimens must be collected in a sterile collection container.

Each specimen must be accompanied by a requisition form, script, electronic order or physician note. Each order must indicate the reason for testing (diagnosis).

• Transport to the laboratory at room temperature.
• Store specimen as whole blood, in original tube, at room temperature and deliver to lab within 24 hours.
• If specimen cannot be delivered within 24 hours, store in refrigerator. Do not freeze specimen.
• Specimens collected on the weekends must be refrigerated upon arrival at HNL Lab Medicine.

• Specimen frozen
• Specimen arriving without any form of patient identification (unlabeled)
• Specimen with attached needles
• Specimen arriving with broken or leaking collection tube
• Unfixed specimen treated with fixative

In a normal cell, the expected signal pattern is two red signals and two green signals. In an abnormal cell containing a typical translocation, the expected signal pattern is one red signal, one green signal, and two fused signals.

• FISH Translocation IGH/BCL2
• IGH::BCL2
• t(14;18)

• Association:
• Follicular Lymphoma