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Acute lymphoblastic leukaemia (M91)

Molecular investigations

Detection of the BCR-ABL fusion gene - screen for the presence of BCR-ABL fusion transcripts using multiplex PCR.

BCR-ABL quantification - quantification of BCR-ABL transcript level and monitoring of minimal residual disease.

BCR-ABL T315I analysis - pyrosequencing for this variant only. M91.11 and M91.12 can be undertaken as sendaway tests. Please contact us to discuss.

Single Nucleotide Polymorphism microarray (SNP Array)

This test is undertaken on bone marrow samples for cases (paediatric and adult) referred for Acute Lymphoblastic Leukaemia (ALL).

SNP arrays involve:

  • hybridisation of patient DNA to a target sequence on a glass slide
  • a labelled fluorescent probe is introduced at the complementary SNP position
  • a laser scanner is used to measure the fluorescent intensity of the probes bound to the patient sample, which is compared to a reference file
  • the fluorescence intensity provides information on both the copy number and the SNP genotype.

This technique allows examination of the whole genome in greater detail than is possible by karyotyping and has a sensitivity of about 10 percent. The analysis software allows cross referencing to international databases to allow identification of the genes in the region of imbalance.

This test detects chromosomal imbalance (copy number gain and loss) and can be used to further define the breakpoints and gene content of known unbalanced chromosome abnormalities.

This test also provides information on ploidy levels and can detect copy number loss of heterozygosity (CN-LOH). This test does not detect balanced rearrangements or point mutations and may not distinguish sub-clones.


As outlined in the Test Directory.


There are several of the rarer FISH investigations outlined in the Test Directory that we do not provide (e.g. M91.25, M91.27 & M91.29 as well as many others).

Please contact us to discuss forwarding the sample elsewhere for FISH investigations.

WGS for diagnostic samples

If there are tumour and germline samples available, along with appropriate consent, these will be forwarded to the WMRGL for further processing.

Last reviewed:10 November 2023