Chromosomal translocations are rare events in CLL. Copy number changes of certain chromosomal regions are however frequent. Some of these have been found to be highly prognostic markers of this disease. CLL testing is performed by MLPA (Multiplex Ligation-dependent Probe Amplification) using a commercial kit manufactured by MRC-Holland. This MLPA test can be used to determine the loss of TP53 (17p13), the RB1 / DLEU / MIRN15A-16 region on 13q14, the ATM gene region on 11q23 and also trisomy 12. This test is designed to detect copy number variation in patients at diagnosis where leukaemic cells represent >30% of cells (Coll-Mulet et al. 2008 BJH 142(5):793-801). Copy number variation is unlikely to be detectable in patients with lower levels of leukaemia cells.

Laboratory contact: Dr Caroline Wickham 01392 408252

Clinical contact: Dr Paul Kerr 01392 402917