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CopyDxSM

Information Sheet Consent Document

How does CopyDxTM quantitative PCR analysis differ from other Diagnostic Tests done by DNA sequencing?

CopyDxSM analysis is a specialized service for the detection of a whole or partial gene deletion or duplication in a single known gene of interest. CopyDxTM is based on the innovative use of quantitative PCR-technology, which has a higher sensitivity for detecting deletions and duplications compared to FISH. It can be ordered for:

  1. Analysis on any gene on our current test menu in which a deletion/duplication is suspected ( http://www.genedx.com/tests_by_gene.php )
  2. As a second tier test on a specimen previously sequenced at GeneDx (a discount applies).
  3. For any gene not on our test menu; GeneDx will custom design a quantitative PCR assay for any gene in which a deletion/duplication is suspected in a patient.
CopyDxSM and GenomeDx sound very similar. What are the similarities and differences between these two tests?

  • Both tests, CopyDxSM and GenomeDx, allow to determine how many copies a person carries for a certain gene.
  • CopyDxSM is based on the use of quantitative PCR (qPCR) technology. This targeted assay can be used to identify a deletion or duplication of a single gene or a known partial gene deletion or duplication in a known gene of interest. It is possible to differentiate between a whole or partial gene deletion/duplication although the exact size/boundaries of the abnormality cannot be determined.
  • GenomeDx is a specially designed, oligonucleotide microarray used for Comparative Genomic Hybridization (oligo aCGH). In one single assay, the entire genome is evaluated for chromosomal aneuploidy as well as regions of gains and losses. This test may establish the size and position of breakpoints of deletions or duplications in reference to individual genes, BAC or FISH clones, or microsatellite markers in the region. Technical limits apply and depend predominantly on the number and density of probes that are used.
What are other possible indications for CopyDxSM quantitative PCR analysis?

  • As a complementary test or substitute for FISH and quantitative microarray analysis when a deletion or duplication syndrome (contiguous or single gene) is suspected.
  • As a confirmation test for a genomic gain or loss identified by genome-wide microarray analysis, such as GenomeDx.
  • To determine the presence or absence of a specific gene within a deleted chromosomal segment (contiguous gene deletion).
  • As second tier test in a Mendelian disorder due to haploinsufficiency when sequence analysis fails to identify a causative mutation; in particular when whole or partial gene deletions are a known cause for the disorder (for example STK11 deletion associated with Peutz-Jegher syndrome, RAI1 deletion associated with Smith-Magenis syndrome).
  • Carrier testing for deletion/duplication syndromes when the specific region is known in an affected relative (i.e., testing of carrier status of female relatives of an affected male with X-linked hydrocephalus due to L1CAM deletion).
How is CopyDxSM analysis ordered?

CopyDxSM quantitative PCR analysis a specialized service tailored to a specific gene or part of a gene. Therefore, it is necessary to discuss any CopyDxSM analysis request prior to sending a specimen. You can use the Contact Us link on our website, e-mail us at genedx@genedx.com or call GeneDx at (301)-519-2100.


What specimen is required?

Our standard specimen requirement for this analysis is a single tube with 1-5 mL blood in EDTA. Do not send buccal swabs/brushes. Please see our standard Sample Requirements page.



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