CGH. Granulocyte DNA from patients and a reference DNA were used to perform custom high-density oligonucleotide CGH arrays. The graphs show the log ratios for all probes located on chromosome 20q. Green represents regions deleted in the patient's DNA. The boundaries are marked by a clear drop in the ratio between the patient's DNA and the reference. Patient Vi384 delineates the centromeric and patient Na293 the telomeric border of the CDR, which spans 9 Mb and includes 93 genes.