Genome diversity comprises single nucleotide polymorphisms, deletions, insertions, and duplications. These gains and losses of DNA segments leading to rearrangements of sequences are termed copy number variations (CNVs). CNVs may disrupt genes and/or alter gene dosage and, thereby, have an impact on both protein-coding and noncoding genes. Accordingly, they affect the activity of various signaling pathways and influence the cell phenotype. They are associated with risks for several severe diseases, in particular cancer. In the current chapter, I introduce a rapid profiling method to identify CNVs in circulating, cell-free DNA by multiplex ligation-dependent probe amplification (MLPA). MLPA represents an efficient method for the detection of CNVs among numerous genes on various chromosomal regions in serum.
