Study shows diagnostic test effective for providing conclusive genetic results
GREENWOOD, SC – The Greenwood Genetic Center (GGC), working with collaborators at Lawson Health Research Institute in Canada and the University of Amsterdam, published a study this month that provides clinical validation of EpiSign, a molecular genomics test that diagnoses rare, heritable neurodevelopmental conditions. GGC has been the sole US laboratory provider of this novel diagnostic test since 2019.
EpiSign analyzes changes that affect gene expression rather than the gene sequence. Researchers have found that certain genetic disorders display unique genomic patterns, or epigenetic signatures, allowing for a diagnosis through EpiSign when traditional genetic testing has been uninformative.
The laboratory testing in the US is performed at GGC while the analysis of the results is performed using machine learning at Lawson where the EpiSign Knowledge Database was developed. This database compiles information on rare genetic diseases using laboratory analyses of the epigenetic signature from patients with suspected genetic abnormalities.
The current study analyzed data from early EpiSign testing to validate the ability of the novel test to make a diagnosis. Epigenetic signatures have been identified for over 40 genetic disorders.
The analysis studied EpiSign test performance and diagnostic yield in 207 subjects from two different cohorts. A targeted group included patients with previous genetic findings that were ambiguous or inconclusive. The second screening group was those with clinical findings consistent with hereditary neurodevelopment syndromes but with no previous genetic findings.
“Of the 207 subjects tested, 57 were positive for a diagnostic episignature including 48 in the targeted cohort, and 9 in the screening cohort. Only four remained inconclusive after EpiSign analysis,” says Dr. Bekim Sadikovic, lead researcher at Lawson and Scientific and Clinical Director of the Verspeeten Clinical Genome Centre at London Health Sciences Centre (LHSC). “This gives us strong evidence for the clinical use of EpiSign, as well as the ability to provide conclusive findings in the majority of subjects tested.”
While currently there are limited treatment options associated with many of these conditions, providing a diagnosis can help physicians better predict the course of the disease, and allows for better planning and support for the patient. EpiSign is the only test in the world that has been clinically validated for epigenetic testing for these types of genetic disorders, and in the US, is only available through GGC.
“Patients with rare diseases often wait years and undergo numerous exams and tests before receiving a correct diagnosis, if one is found at all,” says Matthew Tedder, PhD, staff scientist at the Greenwood Genetic Center, who was involved in the study. “EpiSign provides an additional high-yield diagnostic tool for clinicians to include in their evaluation of patients with undiagnosed diseases, providing better medical management for patients and hope for their families.”
The study, “Clinical epigenomics: genome-wide DNA methylation analysis for the diagnosis of Mendelian disorders“, is published in February’s Genetics in Medicine.
For more information about EpiSign, visit, www.ggc.org/EpiSign.