Information Sheet, including prices and CPT codes Test Submission Form (Test Requisition Form) including Payment Options and Consent Form

FISHonChipDx^NEW - GeneDx now offers a sensitive and cost-effective cytogenetic array CGH test to interrogate subtelomeric and pericentromeric regions for rearrangements and to rule out 65 common or novel microdeletion and microduplication syndromes. This test also includes confirmation of positive results by FISH. GeneDx also offers individual FISH tests for a range of genomic disorders and for subtelomeric and pericentromeric rearrangements.

What is the FISHonChipDx array?

• It is a cytogenetic oligonucleotide array-CGH test
• It is specifically targeted to 65 chromosomal regions associated with common or novel microdeletion and microduplication syndromes
• It covers all subtelomeric and pericentromeric regions
• It is more sensitive than regular FISH testing and may allow determination of the size of a detected genomic imbalance
• It is much more cost-effective than a subtelomere FISH panel or multiple FISH tests
• Positive findings will be confirmed by FISH

What are the test indications for FISHonChipDx?

• As a primary screening test for the diagnosis of persons with unexplained dysmorphic features, birth defects, unexplained mental retardation/developmental delay, multiple congenital anomalies, seizures, or suspicion of a chromosomal imbalance
• As a superior alternative to an expensive subtelomere FISH panel in persons with developmental disabilities/mental retardation. FISHonChipDx offers a first-pass genome scan before high-resolution whole-genome array CGH
• As a replacement test for FISH when a specific microdeletion/microduplication syndrome is suspected

Cytogenetic testing using FISHonChipDx sounds very similar to GenomeDx. What are the similarities and differences between these two tests?

FISHonChipDx analysis is a new targeted array CGH-based test that has been custom-designed to specifically determine copy number imbalances at 65 genomic regions associated with common or newly described microdeletion/microduplication syndromes and at all subtelomeric and pericentromeric regions. It does not have high-density coverage at other regions of the genome, i.e., it cannot substitute for high-resolution analysis of the whole genome, which is possible only with the GenomeDx test. However, FISHonChipDx is useful as a first-pass genome scan and is as an excellent substitute for subtelomere FISH panel testing or individual FISH testing for specific microdeletion/microduplication syndromes. In contrast, the GenomeDx array has a whole-genome design and can detect deletions and duplications =100kb anywhere in the non-repetitive regions of the genome. The GenomeDx design covers over 150 clinically significant regions with higher density (5-20 kb probe spacing), including all the regions targeted on the FISHonChipDx array. The GenomeDx array can therefore identify small, localized rearrangements and imbalances across the entire genome and provide fine-resolution breakpoint mapping for large chromosomal imbalances.

How is FISHonChipDx deletion/duplication analysis ordered?

Please download the submission form for Molecular Cytogenetics services and submit along with one tube with 2-5 ml blood in EDTA and a second tube with 2-5ml blood in heparin.