Acute Lymphocytic Leukemia (ALL) – Ph Like Reflex Panel

CPT Code(s)

88271x12, 88275x12

Performed

Clinical & Molecular Cytogenetics Laboratory

Clinical Indication and Relevance

Fluorescence in situ hybridization (FISH) is a sensitive method to detect smaller genomic changes associated with various hematological malignancies and solid tumors. There are several advantages with FISH technology over routine chromosome analysis and such advantages include the ability of FISH technology to detect genomic abnormalities in non-viable and non-dividing tissues, rapid turnaround time, and increased resolution. However, FISH technology is complementary to routine chromosome analysis and cannot substitute routine chromosome analysis for diagnosis of cancer.
Clinical Background
Acute lymphoblastic/lymphocytic leukemia (ALL) is the most common hematological malignancy seen in children. A large number of specific chromosome abnormalities and/or gene rearrangements are seen in patients with ALL with the incidence of such abnormalities ranging from 65-85% for adults and 60-70% for children. Detection of these abnormalities is vital in stratification of patients into different treatment groups, and it is now mandatory to carry out chromosome and FISH studies, especially in children, for enrollment into Children’s Oncology Group (COG) treatment protocols. Although majority of such abnormalities can be detected on routine chromosome analysis, interphase FISH analysis due to its high sensitivity can detect low-level clones thus identifying prognostically and therapeutically important genetic abnormalities.

Methodology

Culture/Hybridization/Microscopy/Interpretation

The samples are usually cultured for 24 hours before hybridizing with the probes.  After hybridization and post-hybridization washes, the slides are analyzed under a fluorescence microscope equipped with epifluorescence and appropriate filter sets.  Analysis and scoring are carried out by two certified technologists in a blinded fashion.  Results are reviewed by both the laboratory manager and the director.

Specimen Collection / Handling Requirements

In this ALL panel both Ph positive and Ph-like genetic markers are included.  If this panel is ordered, first the Ph positive probes (the first 5 probes) will be performed and if they are negative/normal, then the testing is reflexed to Ph-like panel with the remaining 6 probes.  The probes included in this panel are based on latest NCCN and ASCO guidelines.

Probe List

ALL – Ph Like Reflex
Probe Name	Locus/CHR	Catalogue #
CHIC2	4q12	Cytocell LPH032
BCR/ABL1/ASS1	9q34/22q11.2	Cytocell LPH038
D10Z1/D17Z1	Chromosomes 10/17	Cytocell LPE010G/LPE017R
KMT2A	11q23.3	Cytocell LPH013
ETV6/RUNX1	12p13.2/21q22.12	Cytocell LPH012
CRLF2	Xp22.33/Yp11.32	Cytocell LPH511/512
ABL2	1q25.2	Cytocell MPD2671/2672
CSF1R	5q32	Cytocell MPD2751/2752
PDGFRB	5q32	Cytocell LPH031
JAK2	9p24.1	Cytocell MPD2681/2682
EPOR	19p13.2	Cytocell MPH2741/2742

Minimum Specimen Requirements

Bone Marrow and/or Leukemia Blood

Container: Sodium Heparin (green top tube)

Optimal Quantity: 2-3 ml

Minimum Quantity: 1-2 ml

Storage: Room Temperature

Stability at Room Temperature: 8 hours, then refrigerate

Transportation: Avoid freezing or heating over 35°C

Turnaround time

Final report in 7-10 days

Communication

The morphologic interpretation and correlation of results on all cases is performed by a board-certified doctoral level scientist (laboratory director). The final report has a narrative description of results.  If abnormalities are present, they are explained in a paragraph which helps to clarify and correlate chromosomal findings with phenotype. References are included in the report to help the referring physician with interpretation, which include books or journals that contain appropriate information. Recommendations are made as to any additional testing, if necessary.

View Requisition Sheet