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: Formalin- Fixed Paraffin Embedded (FFPE) Tissue Block or 2 slides from FFPET Block, cut at 4 micron thickness and mounted on charged lysine slides with accompanying H&E slide indicating the region(s) of interest (ROI), if the entire specimen is not tumor.

Specimens should have an ischemia time of < 1 hour and a formalin fixation time of

6 - 72 hours.

Transport to the laboratory at room temperature.

• Specimen arriving without any form of patient identification (unlabeled)
• FFPET sections that are not properly attached to the slide
• FFPET sections with excessive cracks, splits or deterioration that would inhibit analysis
• Broken FFPET slides

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