Detection of an interstitial deletion of 2q21-22 by high resolution comparative genomic hybridization in a child with multiple congenital anomalies and an apparent balanced translocation.

Various molecular cytogenetic techniques are currently available to accurately characterize chromosome rearrangements in patients with multiple congenital anomalies. Among these is comparative genomic hybridization (CGH) whose main advantage is the ability to perform a whole genome scan without prior knowledge of the underlying chromosome abnormality. It has been used mostly in the area of cancer cytogenetics, but its role in clinical genetics is now expanding to even include preimplantation genetic diagnosis. We have used this method to reveal an interstitial deletion in a patient with multiple anomalies, who had for years been thought to have a de novo balanced translocation involving chromosomes 1 and 2. A review of published reports suggests that there is significant phenotypic and genetic heterogeneity in the small group of patients including our own with interstitial deletions of 2q21-q22.