OGM-DxTM Postnatal 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, and unbalanced rearrangements including insertions, inversions, and translocations. This assay may be indicated for individuals who have diagnoses, such as:
OGM-DxTM Postnatal Whole Genome SV reports will include a whole genome analysis of SVs as well as a screen for Fragile X Syndrome (only CGG repeat expansions >250 will be reported).
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
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.
Additionally, OGM analysis provides a screening of the Fragile X repeat region and calculates the probability that the size of the repeat region on each allele exceeds 250 copies of the CGG triplet (beyond the full mutation threshold). The Fragile X analysis produces a probability that a sample’s repeat number (R) is greater than 250.
Optical genome mapping is a technique using a streamlined workflow capable of detecting all classes of structural variants (SVs) in the human genome, including aneuploidies, large and small copy number variants, balanced and unbalanced rearrangements including insertions, inversions, translocations, 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.
Currently, we can perform OGM-DxTM Postnatal Whole Genome SV on peripheral blood (EDTA).
Although this test screens for the common CGG expansion in the FMR1 gene, the limit of detection is 250 or greater repeats. Therefore, only a repeat size of 250 or greater will be reported with a recommendation to follow up with appropriate molecular testing (methylation analysis). It will not be reported if an individual has less than 250 repeats. Due to this, OGM-DxTM Postnatal Whole Genome SV does not rule out all cases of Fragile X Syndrome nor tell if some is a premutation carrier.
OGM-DxTM Postnatal Whole Genome SV is a laboratory developed test for the detection of structural variants (SVs) of diagnostic and prognostic value in individuals with diagnoses including, but not limited to, autism spectrum disorder, developmental delay, intellectual disability, congenital anomalies, dysmorphic features, and epilepsy, and undiagnosed rare genetic disease.
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) as well as a screen for the CGG repeats in the FMR1 gene known to cause Fragile X Syndrome (only CGG repeats >250 will be reported).