Fast Approach for Clarification of Chromosomal Aberrations by Using LM-PCR and FT-CGH in Leukaemic Sample

Abstract

Chromosomal abnormalities, like deletions, amplifications, inversions or translocations, are recurrent features in haematological malignancies. However, the precise molecular breakpoints are frequently not determined. Here we describe a rapid analysis of genetic imbalances combining fine tiling comparative genomic hybridization (FT-CGH) and ligation-mediated PCR (LM-PCR). We clarified an inv(14)(q11q32) in a case of T cell acute lymphoblastic leukaemia with a breakpoint in the TRA/D in 68% of cells detected by fluorescence in situ hybridization. FT-CGH showed several mono- and biallelic losses within TRA/D. LM-PCR disclosed a TRA/D rearrangement on one allele. The other allele revealed an inv(14)(q11q32), joining TRDD2 at 21,977,000 of 14q11 together with the IGH locus at 105,948,000 and 3′-sequence of TRAC at 22,092,000 joined together with IGHV4–61 at 106,166,000. This sensitive approach can unravel complex chromosomal abnormalities in patient samples with a limited amount of aberrant cells and may lead to better diagnostic and therapeutic options.