Clinical applications of comparative genomic hybridization

Purpose: Comparative genomic hybridization (CGH) is a powerful DNA-based cy togenetic technique that allows the entire genome to be scanned for chromos omal imbalances without requiring the sample material to be mitotically act ive. During the past 2 years we received many requests from various medical centers around the country to use CGH to resolve the identity of aberrant chromosomal material. Methods: We report the use of CGH for the evaluation of 12 clinical postnatal cases in which traditional cytogenetic analysis yi elded ambiguous results. This series consisted of five marker chromosomes, five unbalanced translocations, and two intrachromosomal duplications. Resu lts: Identification and characterization of the additional unknown chromoso mal material was achieved with use of CGH. All CGH findings were validated by traditional fluorescence in situ hybridization and other specialized sta ining techniques. Conclusions: These results demonstrate the effective use of CGH as a focused, single-step method for the identification of chromosom al material of unknown origin.