Also known as:CLL microarray, Chronic Lymphocytic Leukemia array, CLL array
Oncology - Lymphoid neoplasms
Use of test
Changes in chromosome structure and number in leukaemic cells can provide important prognostic and therapeutic information in patients with chronic lymphocytic leukaemia (CLL). Genome-wide microarray is used to detect gains or losses of genetic material (including the frequent abnormalities, 13q deletion, trisomy 12, ATM deletion at 11q and TP53 deletion at 17p), along with a genome-wide survey for other deletions, duplications and regions of homozygosity.
The laboratory report defines the changes in the patient's malignant cells and relates these changes to the current management recommendations, where available.
This is an assay for non-heritable mutations. It does not raise issues of ethics or consent that are different from most other investigations ordered in the routine care of a patient.
The relative amounts of genetic material from hundreds of thousands of small regions from all chromosomes are measured. Deviations from the expected values can identify deletions and duplications.
Sonic Genetics uses a single nucleotide polymorphism (SNP) microarray, which provides additional genotype information compared with CGH microarray. SNP microarrays can identify large regions of homozygosity.
Compared with FISH panel testing, microarray can detect a broader range of genomic abnormalities, across all chromosomes. However, FISH testing has a higher sensitivity to detect low level targeted deletions and duplications, and microarray cannot detect balanced rearrangements such as translocations.
Requesting the test
This test is usually requested by a haematologist or oncologist.
0.5 mL bone marrow in transport media.
To help ensure the quality of the test, a genetic test should be done with a dedicated sample whenever possible i.e. a sample collected specifically for that test rather than a sample that is used for multiple tests.
We recommend that the patient or another adult check the labelling of request forms and sample tubes.
18 business days from receipt of the specimen
The Medicare details, including descriptor and schedule fee, are listed under MBS item 73343.