Multiplex Ligation-Dependent Probe Amplification and Fluorescence in Situ Hybridization Are Complementary Techniques to Detect Cytogenetic Abnormalities in Multiple Myeloma

Genes Chromosomes Cancer. 2013 Sep;52(9):785-93. doi: 10.1002/gcc.22074. Epub 2013 May 30.

Abstract

Multiple myeloma (MM) is a genetically heterogeneous disease with diverse clinical outcomes. Interphase fluorescence in situ hybridization (i-FISH) is the most commonly used approach to detect recurrent cytogenetic abnormalities in this malignancy. We aimed to assess the performance of multiplex ligation-dependent probe amplification (MLPA) to reveal copy number abnormalities (CNAs) in MM. Diagnostic bone marrow samples from 81 patients were analyzed using 42 MLPA probes for the following regions: 1p32-31, 1p21, 1q21.3, 1q23.3, 5q31.3, 12p13.31, 13q14, 16q12, 16q23, and 17p13. All samples were also screened by i-FISH for the presence of hyperdiploidy, deletion/monosomy of chromosome 13, deletion of TP53, disruption of the immunoglobulin heavy-chain gene, t(4;14), t(11;14), t(14;16), t(8;14), gain of 5q and abnormalities of chromosome 1. A total of 245 alterations were detected in 79 cases (98%). Investigating the same aberrations, the two methods showed a congruency of higher than 90%. A low proportion of cells with the relevant abnormality, focal CNAs and unmatched probes were responsible for the discrepancies. MLPA revealed 95 CNAs not detected by i-FISH providing additional information in 53 cases (65%). Scrutiny of CNAs on chromosome 1, using more than 20 probes, revealed significant heterogeneity in size and location, and variable intra-chromosomal and intra-clonal rates of loss or gain. Our results suggest that MLPA is a reliable high-throughput technique to detect CNAs in MM. Since balanced aberrations are key to prognostic classification of this disease, MLPA and i-FISH should be applied as complementary techniques in diagnostic pathology.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chromosome Aberrations*
  • Chromosomes, Human, Pair 1 / genetics
  • Cytogenetic Analysis / methods*
  • DNA Copy Number Variations
  • Humans
  • In Situ Hybridization, Fluorescence*
  • Multiple Myeloma / genetics*
  • Multiple Myeloma / pathology
  • Multiplex Polymerase Chain Reaction*