COMPARATIVE GENOMIC HYBRIDIZATION IN CLINICAL CYTOGENETICS

We report the results of applying comparative genomic hybridization (C GH) in a cytogenetic service laboratory for (1) determination of the o rigin of extra and missing chromosomal material in intricate cases of unbalanced aberrations and (2) detection of common prenatal numerical chromosome aberrations. A total of 11 fetal samples were analyzed. Sev en cases of complex unbalanced aberrations that could not be identifie d reliably by conventional cytogenetics were successfully resolved by CGH analysis. CGH results were validated by using FISH with chromosome -specific probes. Four cases representing common prenatal numerical ab errations (trisomy 21, 18, and 13 and monosomy X) were also successful ly diagnosed by CGH. We conclude that CGH is a powerful adjunct to tra ditional cytogenetic techniques that makes it possible to solve clinic al cases of intricate unbalanced aberrations in a single hybridization . CGH may also be a useful adjunct to screen for euchromatic involveme nt in marker chromosomes. Further technical development may render CGH applicable for routine aberration screening.