CytoScan HD
Test Name: CytoScan HD – High-Resolution Chromosomal Microarray Analysis
What is CytoScan HD?
CytoScan HD is a high-resolution, genome-wide chromosomal microarray test used to identify clinically relevant chromosomal abnormalities. It analyzes DNA for changes in chromosome copy number and can also detect regions of loss of heterozygosity (LOH), absence of heterozygosity (AOH), and certain uniparental disomy (UPD) patterns.
What does the test detect?
- Chromosomal deletions and duplications
- Copy number gains and losses
- Aneuploidies and other genomic imbalances
- Loss of heterozygosity (LOH/AOH)
- Copy-neutral LOH in appropriate applications
- Certain UPD/isodisomy patterns
- Mosaic chromosomal abnormalities, depending on the level present
- Chromosomal abnormalities associated with developmental and neurological disorders and selected hematological malignancies
Why is CytoScan HD useful?
Unlike conventional karyotyping, which has comparatively lower resolution, chromosomal microarray can identify many smaller genomic imbalances that may not be visible by routine chromosome analysis. The platform combines copy-number probes with high-density SNP markers to provide genome-wide information from a single array.
Common Clinical Applications
- Developmental delay and intellectual disability
- Autism spectrum and neurodevelopmental disorders
- Multiple congenital anomalies
- Unexplained dysmorphic features
- Selected prenatal/postnatal chromosomal investigations
- Hematological malignancies and other cancer-related cytogenomic investigations
Sample:
Sample requirements depend on the clinical application and laboratory protocol. Peripheral blood, bone marrow, cultured cells, amniotic fluid/cells, chorionic villi, tissue, or extracted DNA may be suitable for different applications.
Method:
DNA extraction → amplification/processing → hybridization to a high-density SNP/copy-number microarray → scanning → bioinformatic analysis → clinical interpretation.
Important Note:
A normal CytoScan HD result does not exclude all genetic disorders. Small sequence-level variants, some balanced chromosomal rearrangements, very small abnormalities below assay resolution, and certain epigenetic abnormalities may require other molecular or cytogenetic tests. Results should be interpreted along with the patient's clinical findings and, when appropriate, genetic counseling.
