Genetic Testing Company | The DNA Diagnostic Experts | GeneDx

Cytogenetics

 

 

Cytogenetics and Chromosomal Microarray at GeneDx

 

GeneDx provides comprehensive molecular cytogenetic testing. We offer a high-resolution whole-genome chromosomal microarray (CMA) to evaluate the entire genome for copy number changes, to detect uniparental disomy (UPD), and to detect single-gene deletions or duplications. Traditional chromosome analysis and FISH studies can also be ordered as stand-alone tests or in conjunction with CMA or gene-specific DNA sequencing tests.

Parental testing is often recommended when a patient is found to have a genomic imbalance. This testing is standard of care in many circumstances and also helps interpret findings of unclear significance in a proband.

For more information, click on the appropriate tab below:

 

GeneDx offers a custom-designed postnatal chromosomal microarray (CMA) for detection of pathogenic copy number changes. The whole-genome CMA uses 182,000 probes to evaluate the entire genome for chromosomal aneuploidy and intrachromosomal deletions and duplications. In addition, SNP genotyping probes on all chromosomes allows detection of large blocks of homozygosity, which may represent uniparental disomy. Lastly, this array also contains exon-level probe coverage to detect single-exon deletions or duplications in approximately 65 genes associated with developmental disorders.

*Chromosomal microarray testing is also available for prenatal samples. For more information regarding prenatal cytogenetic testing services at GeneDx, please click here

Test Available More Information

GenomeDx: Whole-Genome Chromosomal Microarray (CMA)

 
 
Whole-Genome Chromosomal Microarray (CMA) for Product of Conception (POC)
 
 

 

The ISCA consortium

GeneDx participates in the International Standards for Cytogenomic Arrays (ISCA) consortium. Anonymized CMA data and clinical information may be submitted to a HIPAA-compliant, de-identified database as part of the National Institutes of Health’s effort to improve diagnostic testing and enhance our understanding of the relationships between genetic changes and clinical symptoms. Visit the consortium website here. Confidentiality and full anonymity of each submission is maintained. Please use the current GeneDx cytogenetics test requisition and consent forms when requesting testing. If these GeneDx forms are not sent with the submitted specimen, CMA data will be anonymized and submitted to the ISCA database. If you wish not to have genomic information derived from your submitted sample sent to the database, please email iscaoptout@genedx.com.

 

 

GeneDx offers traditional cytogenetic testing including chromosome analysis and FISH studies. Karyotyping by G-banding is available for analysis of the number and structures of individual chromosomes. Additionally, individual FISH assays are available for several genomic disorders, and also for intrachromosomal abnormalities, such as terminal deletions or duplications, subtelomeric rearrangements, and for pericentromeric imbalances (supernumerary marker chromosomes).

*Chromosome analysis and FISH studies are also available for prenatal samples. For more information regarding prenatal cytogenetic testing services at GeneDx, please click here

Test Name Indication for Testing More Information

Postnatal chromosome analysis

  • Peripheral blood – routine study
  • Peripheral blood – rule out mosaicism
  • Products of conception
  • Multiple congenital anomalies with or without intellectual disability
  • Family history of chromosome anomaly
  • Short stature
  • Infertility or multiple spontaneous abortions

 

 

FISH Analysis

  • FISH probes are available for some common microdeletion / microduplication syndromes and subtelomeres
  • Please contact a genetic counselor at 301-519-2100 to inquire about custom FISH tests.
  • Suspected common microdeletion or microduplication syndrome
  • Confirmation of certain karyotypes with terminal rearrangements
  • Mosaicism for a genomic imbalance
 

FISH Follow Up Analysis

  • Evaluation of a specific cytogenetic region(s) as a follow-up to chromosomal microarray analysis performed by GeneDx

Parental testing policy: GeneDx recommends parental testing when a patient is found to have a genomic imbalance. Parental analysis is used to evaluate the inheritance of an abnormality (familial or de novo) and may also clarify the clinical significance of copy number changes. GeneDx uses FISH, quantitative PCR (qPCR), targeted CMA or G‐band chromosome analysis, as appropriate, for parental analysis.

* For clinically well‐characterized genomic imbalances, parental analysis is available as a separate test for an additional cost. Additionally, testing other family members is available as a separate test for an additional cost. Price and CPT codes for known familial deletion/duplication test are provided below.

* For genomic imbalances of unclear significance, GeneDx offers free parental analysis. The turn-around time for an updated report including parental results is 4-6 weeks.

Known Familial Deletion/Duplication Testing

 

 

Array CGH Guide for Physicians and Patients

Click here to view the online version of our “Genome-Wide Microarray Analysis” flipbook, or to order a printed copy of the flipbook please send an email to zebras@genedx.com with your request.

Genome Analysis Tool

Array CGH reports from GeneDx contain data that can be used to explore genomic regions of interest in the UCSC genome browser. Click here  to sign in  with the username “GenomeDx” and password “report”. Enter the sequence coordinates from the report in the format “chr#:xxxxx-xxxxx”. Array probes are shown on the top half. Questions about array probe coverage or interpretation of findings can be directed to our genetic counselors or clinical cytogeneticists.

The ISCA consortium

GeneDx participates in the International Standards for Cytogenomic Arrays (ISCA) consortium. Anonymized CMA data and clinical information may be submitted to a HIPAA-compliant, de-identified database as part of the National Institutes of Health’s effort to improve diagnostic testing and enhance our understanding of the relationships between genetic changes and clinical symptoms. Visit the consortium website here to find out more information. Confidentiality and full anonymity of each submission is maintained. Please use the current GeneDx cytogenetics test requisition and consent forms when requesting testing. If these GeneDx forms are not sent with the submitted specimen, CMA data will be anonymized and submitted to the ISCA database. If you wish not to have genomic information derived from your submitted sample sent to the database, please email iscaoptout@genedx.com

Genomic Oligoarray and SNP Array Evaluation Tool v1.0

Significant absence of heterozygosity (AOH) suggests identity by descent (IBD) (e.g. parental consanguinity). Regions of AOH in an individual may have clinical significance if both parents are heterozygous carriers of an autosomal recessive mutation in the same gene located within one of these genomic regions. A list of recessive disorders mapping to any identified homozygous blocks can be obtained using the online resource provided here.

 

References and other resources 

 

 

 

 

 

 

Back To Top