aCGH was performed following manufacturer protocol modified by Hostetter et al. (Hostetter et al., 2010 (link)). One microgram of genomic DNA extracted from archival material and 400 ng of reference DNA were labeled with Cyanine 5 and 3, as described previously (Perot et al., 2012 (link)). Labeled DNA was hybridized to Agilent arrays (Agilent Technologies) with a 60k resolution across the genome. Slides were scanned on Agilent microarray scanner and analyzed using Feature extraction software, version 10.5.1.1 (Agilent Technologies) and Agilent genomic workbench lite 6.5.0.18. The ADM-2 algorithm was used to identify DNA copy number anomalies at the probe level. Homozygous deletion was considered when log2 ratios of targeting probes were below 1. Intermediate log2 ratios values between −1 and −0.25 do not allow to be conclusive as to whether the deletion is homo or heterozygous. A low-level copy number gain was defined as a log 2 ratio > 0.25. To further characterize the 22q11 somatic deletion identified in case ES#6, we used custom-designed aCGH 180k Agilent array with high density coverage of 22q11 locus (in which 200 oligonucleotide probes target SMARCB1).