Quantitative PCR evaluation of deletions/duplications identified by array CGH

Genomic deletions/duplications detected by array comparative genomic hybridization (aCGH) should be confirmed by an independent technology. This approach allows also to test, at low cost, inheritance of the imbalance. In the present study we explored the use of quantitative PCR (qPCR) to confirm aCGH-detected potentially clinically relevant imbalances. Only samples with DLRS <0.2 were tested for confirmation. aCGH results were confirmed in 102/118 cases (86.5%). A major element for non-confirmation was the dimension (and the probe coverage) of the putative aberration. Imbalances detected by 10 or less probes in aCGH assay were not confirmed in 11 out of 41 cases (26.8%), while those ones detected by 20 or more probes were always confirmed (46 cases). Among not confirmed imbalances, no statistical difference was found between deletions and duplication. Our data indicate that validation should be required for imbalances detected by less than 10 probes in aCGH assays.