CytoScan® Dx Assay is a qualitative assay intended for the postnatal detection of chromosomal copy number variants (CNV) in genomic DNA (gDNA) obtained from peripheral whole blood in patients referred for chromosomal testing based on clinical presentation. CytoScan Dx Assay is indicated for the detection of CNVs associated with developmental delay and/or intellectual disability (DD/ID), congenital anomalies, and/or dysmorphic features. Assay results are intended to be used in conjunction with other clinical and diagnostic findings, consistent with professional standards of practice including confirmation by alternative methods, parental evaluation, clinical genetic evaluation, and counseling as appropriate. Interpretation of assay results is intended to be performed only by healthcare professionals board certified in clinical cytogenetics or molecular genetics. The assay is intended to be used on the GeneChip® System 3000Dx and analyzed by Chromosome Analysis Suite Dx Software (ChAS Dx Software).This device is not intended to be used for standalone diagnostic purposes, pre-implantation or prenatal testing or screening, population screening, or for the detection of, or screening for, acquired or somatic genetic aberrations.
Technical features and limitations**
- The smallest CNV regions that ChAS Dx calls are 25 kb and 25 markers for losses, and 50 kb and 50 markers for gains. Performance of the assay has not been assessed below these settings.
- Mosaic copy number <20% may not be reliably detected and detection sensitivity is affected by the size of the CNV.
- Loss (absence) of heterozygosity (LOH/AOH) has a filter setting of 3 Mb. Performance of the assay has not been assessed for LOH below this setting for reporting.
- CytoScan Dx Assay cannot identify balanced chromosomal rearrangements, such as translocations or inversions.
- The assay is validated for use with peripheral whole blood anticoagulated with heparin or EDTA. It has not been validated for any other specimen type.
- CytoScan Dx Assay is limited to personnel trained in this assay.
**For details on technical performance and a full list of limitations, please refer to the IFU.
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