180K Oligonucleotide + SNP Array CGH
Array-Based Comparative Genomic Hybridization
Genetics Center is pleased to offer the latest in array-based comparative genomic hybridization (CGH) testing. Our high-resolution array containing 180,000 oligonucleotide and SNP probes is based on the International Standards for Cytogenomic Arrays (ISCA) Consortium chip design. As there are many abnormal phenotypes that are associated with chromosomal imbalances (subtle gains or losses of genetic material), the identification of specific abnormalities (or copy number variants) is helpful for accurate diagnosis and medical management. Array CGH is a technology with the ability to detect chromosome imbalances beyond that of more conventional techniques.
Reasons for Testing
Postnatal Abnormalities (Pediatric and Adult):
The American College of Medical Genetics (ACMG) has recommended the use of array CGH as a first-tier test in the initial postnatal evaluation of an individual with developmental delay/intellectual disability, autism spectrum disorder, or multiple congenital anomalies that are not part of a recognizable syndrome. To provide further clarification of a chromosome rearrangement or abnormality initially detected by conventional chromosome analysis.
Retesting at Higher Resolution:
Previously performed lower-resolution microarray studies with normal results may be considered to be retested at the higher 180k resolution.
Prenatal Abnormalities:
Please see our GCPrenatal Array for further information
Products of Conception (POC):
Please see our GCPrenatal Array for further information
180K CGH Testing Methods
An array chip is a slide with thousands of DNA probes that are specific to regions of our chromosomes. The probes in the array were specifically selected to identify well-known imbalances in chromosomes and to evenly cover the entire genome as well.
Abnormalities Detected by Array CGH include:
- Well-known microdeletion and duplication syndromes, such as Williams syndrome, 22q11.2 deletion syndrome, Prader-Willi syndrome, Angelman syndrome, and many others.
- Chromosomal aneuploidies, such as Down syndrome, trisomy 18, and many others.
- Gains or losses at the ends of chromosomes.
- Gains or losses in certain genomic regions known to be associated with autism.
- Other copy number variations of unclear clinical significance may be also detected via this testing modality.
Turn Around Time
10 days or fewer
Specimen Requirements and Shipping/Handling
For Postnatal Samples
One vacutainer with 1-5 mL whole blood in EDTA (lavender top), AND one vacutainer with 1-3 mL whole blood in sodium heparin (green top) are to be submitted. To request a DNA Mouthwash Collection Kit please contact Genetics Center at (714)288-3500.
Shipping:
Blood Samples
Store blood at 4°C until shipment. Ship at ambient temperature in an insulated container via overnight delivery within 96 hours of collection.
Send Specimen(s) to:
211. S Main Street
Suite AA
Orange, CA 92868
Tel: (714)288-3500
Required Forms
Test Limitations
Array CGH cannot detect certain chromosome rearrangements, such as balanced translocations or inversions, polyploidy, or intragenic mutations.
CPT Codes
CPT’s: 81229, G0452