A publication from scientists and clinicians at the Institute for Human Genetics and the Benioff Children’s Hospital at the University of California, San Francisco (UCSF) evaluated the ability of Bionano’s optical genome mapping technology and another genome analysis method to diagnose children with genetic conditions who previously went undiagnosed by the standard of care methods alone. Of the 50 children in the study, the optical genome mapping results were sufficient to definitively diagnose 6 patients (or 12%) and, for another 10 patients (or 20%), the Bionano data revealed candidate pathogenic variants. Upon further analysis, it is expected that an additional 3 patients could be diagnosed with the Bionano data, bringing the total of definitively diagnosed patients to 9 (or 18%).
As described in the publication, the UCSF team performed full genome analysis by combining optical genome mapping with Bionano technology and linked-read sequencing on 50 undiagnosed patients with a variety of rare genetic diseases and their parents to determine if this full genome analysis method could help solve cases that had not been diagnosed with previous testing. Of the 50 cases, 42 were previously analyzed by CMA, the first tier medical test for genetic disease cases, and 23 had previously been analyzed with commercial trio whole exome sequencing, and no pathogenic or likely pathogenic variants were identified by these methods.
Bionano’s optical genome mapping technology identified a number of pathogenic variants unidentified by CMA and undetectable by WES, including duplications and deletions that were too small to be identified by CMA, or occurred in regions of the genome not typically covered by CMA or WES. Of the additional 7 patients with variations considered to be candidates for pathogenic variants, the findings included deletions, duplications, and inversions. Before concluding that these variants are sufficient to diagnose the patients, further analysis is required since these variants had not previously been reported in patients with similar disease.
Click here to watch the recent webinar featuring Dr. Pui-Yan Kwok discussing 6 of the specific patients diagnosed by optical genome mapping. You can also click here to find the preprint paper published in medRxiv. Read the full Press Release here.