Application of CGH-array for the detection of genomic rearrangements responsible for sindromic mental retardation of unknown cause

Developmental delay/intellectual disability (DD/ID)affects 2% of our population. However, most patients are often left without aspecific diagnosis,with the corresponding consequences for the patients and their families. The application of microarray technology in the study of patients with DD/ID allows whole-genome analysis with a high resolutionand performance. Here we present the results of four cases included in a series of 246 patients with DD/ID, as part of the screening of the genetic causes responsible for their phenotype. Whole genome array-CGH was performed on Agilent oligo-chip 44K as recommended (human genome CGH microarray G4426B or custom design focused on ID/TEA with the Design ID 035925 from Agilent Technologies, Palo Alto, CA). The patients’ DNA samples were tested against a pool of sex-matched normal DNA samples, all of them (patients and normal controls) from our geographical area. Scanned images were quantified using Agilent Feature Extraction Software (v9.0). The results were analyzed using Agilent Genomic Workbench software. Annotations have been obtained from UCSC (http://genome.ucsc.edu) based on human genome build GRCh37/hg19.