Test Directory

12cen, 12p11.1-q11.1

In CLL, the most frequent chromosomal aberrations are deletions of 13q [del(13q)], 11q [del(11q)], 17p [(del(17p)] and trisomy 12. Occurring in 50-60% of patients, del(13q) removes the DLEU2-mir-15-16 cluster, which regulates expression of anti-apoptotic and cell cycle regulatory proteins. del(11q), detected in 10-20% patients, removes ATM, while del(17p) (5-10% of patients) results in loss of TP53. Trisomy 12 occurs in 15-20% of patients, although the genes involved remain unknown. The most frequently mutated genes in CLL/SLL at the time of first treatment are NOTCH1 (10-15%), ATM (10-15%), SF3B1 (10%), TP53 (5-10%), and BIRC3 (5%). FISH for abnormalities of chromosome 12/13q can be performed on 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 aqua signals. In an abnormal cell containing three copies of chromosome 12, the expected signal pattern is 3 aqua signals.

• FISH Centromere 12
• CEP12
• 12cen