Variability in interpreting and reporting copy number changes detected by array-based technology in clinical laboratories

Purpose: The purpose of this study was to assess the variability in interpretation and reporting of copy number changes that are detected by array-based technology in the clinical laboratory. Methods: Thirteen different copy number changes, detected by array comparative genomic hybridization, that have not been associated with an abnormal phenotype in the literature were evaluated by directors from 11 different clinical laboratories to determine how they would interpret and report the findings. Results: For none of the thirteen copy number changes was there complete agreement in the interpretation of the clinical significance of the deletion or duplication. For some cases, the interpretations ranged from normal to abnormal. Conclusion: There is a need for more specific guidelines for interpreting and reporting copy number changes detected by array-based technology to clearly and more consistently communicate the clinical significance of these findings to ordering providers.