Chromosomal imbalances, recognized as the major cause of mental retardation (MR), are often due to submicroscopic deletions or duplications not evidenced by conventional cytogenetic methods. Array-based comparative genomic hybridization (array-CGH) improves considerably the detection rate of submicroscopic chromosomal abnormalities and has proven to be an effective tool for detection of submicroscopic chromosome abnormalities in children with MR and/or multiple congenital defects. Observations of array-CGH deletions in defined chromosomal regions linked to a clinical phenotype will more and more allow to define genotype-phenotype correlations. We report here the case of a 10-year-old female with a de novo 7.8 Mb deletion in the 6q13-6q14.1 ascertained by array-CGH. The clinical features of this patient include psychomotor and language delay associated with minor dysmorphic features.