Diagnosis of leukaemias – molecular techniques
Polymerase chain reaction (PCR) is a method used for the detection of specific gene regions, e.g. specifically after rearrangement.
After gel electrophoresis, PCR products are visualised by DNA staining. Different PCR products of 9 patients of the rearranged fusion gene BCR-ABL1 in CML discriminate the breakpoint (A).
Quantitative PCR (qPCR) (B) is a highly sensitive method to detect even low levels of tumour burden. In certain AML and CML, qPCR is validated for MRD detection.
Molecular sequencing techniques have enabled fast and accurate analysis from single genes to whole genomes.
The first cancer genome reported was an AML genome published in Nature in 2008.
The Cancer Genome Atlas project has added numerous AML genomes, identifying driver and passenger mutations.
Those analyses have shown that AML is a disease with only few recurrent mutations.
Genetic events in AML occur in 9 different functional classes. Some mutations are strongly associated with each other, while others are mutually exclusive (Chen et al. 2013).
Gene panel sequencing is on its way to becoming a routine measure in the diagnosis of leukaemias and MDS, and is of diagnostic and prognostic value.
Revision Questions
- Which molecular techniques are used in leukaemia diagnosis?
- What is the role of real-time PCR in molecular diagnostics?
- What is the role of gene sequencing in establishing the diagnosis?
