Kivonat:
Analysis of DNA copy number aberrations (CNAs) plays an important role in the
routine diagnostic workup of hematological malignancies. Since these alterations are
frequently of clinical significance there is a need for their fast and cost-efficient detection.
The multiplex ligation-dependent probe amplification (MLPA) is a PCR based method
enabling assessment of CNAs at 50-60 different loci and is also capable of the
simultaneous detection of point mutations. The next generation sequencing based digital
MLPA (dMLPA) can be even more efficient with analyzing the CNA status of 500 to
1000 loci in one run.
In our study, we examined the efficacy of the conventional MLPA in samples
from 18 newly diagnosed and 6 ibrutinib treated CLL patients. We also tested a novel
dMLPA assay developed for MM in bone marrow samples of 56 MM patients.
Additionally, we utilized a dMLPA assay in pediatric ALL for the detection of clinically
relevant aberrations and dissection of mechanisms leading to disease relapse. We paid
special attention to the identification of clinically relevant abnormalities and the
dissection of the genetic alterations leading to relapse.
Using conventional MLPA in CLL, we identified prognostic aberrations in several
cases and we also successfully applied the method to reveal patterns of clonal evolution
induced by ibrutinib treatment. In MM, we were the first in the international literature to
demonstrate the effectiveness dMLPA in detailed analysis of CNAs with prognostic and
predictive value in the disease. In childhood ALL, in addition to mapping clinically
relevant CNAs using dMLPA, three different clonal mechanisms were discovered based
on the CNA profiles in paired diagnostic and relapsed samples. Furthermore, we
introduced a new risk classification system by combining dMLPA-defined CNAs and
cytogenetic abnormalities.
Based on our study, MLPA-based techniques represent useful complementary
approaches to methods used in the routine diagnostic setting and can also be successfully
applied in research of malignant hematological diseases.
