Clinical performance of the CytoScan Dx Assay in diagnosing developmental delay/intellectual disability.

Abstract

The prevalence of developmental disabilities in the United States is reported to be 13.87% across all racial, ethnic, and socioeconomic groups. Microarrays have been recommended as first-tier tests for these patients. This study reports the diagnostic yield and potential actionability of findings using a high-density chromosomal microarray (CMA). The diagnostic yield of CytoScan Dx Assay in 960 patients was assessed with the Riggs criteria of actionability to evaluate predicted clinical utility. Eighty-six percent of the subjects were assessed using a microarray as part of historical routine patient care (RPC). The rate of pathogenic findings was similar between RPC (13.3%) and the CytoScan Dx Assay (13.8%). Among the 138 patients who did not receive microarray as RPC, the diagnostic yield for CytoScan Dx Assay was 23.9% as compared with 14.5%, indicating a 9.4% improvement when using higher-resolution methods. Thirty-five percent of patients with abnormal findings had predicted clinical management implications. This is the first study to assess the clinical performance of CytoScan Dx Assay. The assay's diagnostic yields are similar to those found in other studies of CMAs. Thirty-five percent of patients with abnormal findings are predicted to have clinical management implications that may improve health outcomes.