Chromosome Analysis/FISH

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
  • Skin / other tissue
  • 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
 Test Info Sheet