What is OGM-DxTM Prenatal Whole Genome SV?

OGM-DxTM Prenatal Whole Genome SV is a laboratory developed test (LDT) that detects structural variants (SVs) across the genome and provides comprehensive testing for most common and rare chromosomal abnormalities.

This LDT utilizes optical genome mapping (OGM), a technique that provides genome-wide assessment of all classes of SVs, including: aneuploidies, large and small copy number variants, balanced and unbalanced rearrangements including insertions, inversions, and translocations.  This assay may be indicated for fetuses where a genetic anomaly is suspected, such as:

  • Abnormal ultrasound or positive non-invasive prenatal screening (NIPS)
  • Fetal abnormalities, such as:
    • Neural tube defects
    • Heart, limb or other organ defect
    • Cleft lip or palate
    • Growth restriction
  • Previous child with chromosomal abnormality
  • Spontaneous fetal demise of unknown origin (any gestational age)
  • History of recurrent pregnancy loss
Accepted Specimens
  • Frozen cell pellets derived from cultured amniocytes or chorionic villi
  • Amniotic fluid or chorionic villi sample cultures in T25 flasks (70% confluency)

Clinical Support for OGM-DxTM Prenatal Whole Genome SV Testing

Bionano Laboratories offers clinical support to patients and providers through access to our genetic counselors who can discuss testing capabilities, strategy, informed consent, and results.

Providers can call our genetic counselors at

801.931.6191

Optical genome mapping (OGM) is currently performed using the commercially available Saphyr® system (Bionano Genomics, Inc. USA). This technique is based on site-specific labeling of ultra-high molecular weight DNA followed by imaging of the DNA molecules during linearization within nanochannel arrays.  All classes of SVs are detected, including aneuploidies, large and small copy number variants, balanced and unbalanced rearrangements including insertions, inversions, and translocations. Polymorphic SVs are enriched by filtering against an OGM control SV database. OGM data analysis is performed using a graphical user interface tool for variant visualization, interpretation, and curation. Genome-wide SVs are classified according to standard medical guidelines by board certified laboratory directors.

What is optical genome mapping?

Optical genome mapping is a technique using a streamlined workflow capable of detecting all classes of structural variants (SVs) in the human genome, including deletions, duplications, insertions, translocations, inversions, and repeat contractions and expansions, within the limits of resolution for each type of SV. The OGM technique relies on the imaging of labeled (direct label and stain, DLS) ultra-high molecular weight DNA molecules during flow within nanochannels. The DLS method, where fluorescent labels are attached to a 6 bp sequence motif, provides an average genome-wide resolution of approximately of 5 kbp. The labeled DNA is linearized in nanochannel arrays and imaged for the generation of digital barcodes for mapping the SVs in the human genome. Learn more about OGM data services.

What sample types can OGM-DxTM Prenatal Whole Genome SV be performed on?

Currently, we can perform OGM-DxTM Prenatal Whole Genome SV on:

  • Frozen cell pellets derived from cultured amniocytes or chorionic villi
  • Amniotic fluid or chorionic villi sample cultures in T25 flasks (70% confluency)

Does Bionano Laboratories perform maternal cell contamination testing?

No. We do recommend this test be performed before sending us cultured fetal or placental cells; however, it is not a requirement.

What are indications for ordering OGM-DxTM Prenatal Whole Genome SV?

Indications may include:

  • Abnormal ultrasound or positive non-invasive prenatal screening (NIPS)
  • Fetal abnormalities, such as:
    • Neural tube defects
    • Heart, limb or other organ defect
    • Cleft lip or palate
    • Growth restriction
  • Previous child with chromosomal abnormality
  • Spontaneous fetal demise of unknown origin (any gestational age)
  • History of recurrent pregnancy loss

Please note, OGM-DxTM Prenatal Whole Genome SV should only be ordered on fetuses.

What is OGM-DxTM Prenatal Whole Genome SV?

OGM-DxTM Prenatal Whole Genome SV is a laboratory developed test for the detection of structural variants (SVs) of diagnostic and prognostic value. OGM uses ultra-high molecular weight DNA extracted from blood to detect these SVs, including aneuploidies, large and small copy number variants, rearrangements, insertions, inversions, and translocations. Reports will include a whole genome analysis to assess for complex genomes (similar to karyotyping).