ERBB2 and hereditary disease: This technique was introduced in 2002 and over the years has gained widespread clinical acceptance for the identification of gene copy number changes in a broad range of genetic diseases to identify aneuploidy and trisomies, and more recently for HER2 amplification (White et al., 2004; Jankowski et al., 2008; Kozlowski et al., 2008; Farshid et al., 2011).