Study Shows that OGM Plays an Important Role in Efficient Diagnosis of FSHD
Nov 30, 2023
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SAN DIEGO, Nov. 30, 2023 (GLOBE NEWSWIRE) -- Bionano Laboratories today announced the publication by scientists at Revvity Omics (formerly Perkin Elmer Genomics), Leiden University Medical Centre, Bombay Hospital, and UT Dallas, of the largest peer-reviewed study to date on the use of optical genome mapping (OGM) to diagnose facioscapulohumeral muscular dystrophy (FSHD).
The publication describes the evaluation of an OGM-based laboratory developed test (LDT) including the assessment of the accuracy and precision of the OGM test against the prior standard, Southern blot analysis by gel electrophoresis. The study authors assessed the yield of OGM for diagnosing FSHD1 and the ability of next generation sequencing (NGS) to be used as a reflex test to identify FSHD2. The study, which included 547 cases with a clinical suspicion of FSHD, used an algorithm that utilized OGM to identify the FSHD haplotype and quantitate the number of D4Z4 repeats found on chromosome 4. Researchers used the NGS LDT to identify sequence variants, using NxClinical software to detect copy number variants in the SMCHD1 gene to diagnose cases with FSHD2. The authors noted that, when compared to other methods, OGM has the advantage of being able to identify mosaicism and to detect repeat sizing on 4q and 10q together with haplotyping in a single run.
Compared to Southern blot, the OGM LDT was 100% accurate and precise
The OGM LDT identified 56% of cases positive for FSHD1 (308 out of 547 samples)
252/547 cases were referred for concurrent testing for FSHD1 and FSHD2
Sequencing identified FSHD2 in 3.6% of cases (9 out of 252 samples)
The OGM LDT detected mosaic alleles with at least one contracted 4qA allele in 3% of samples positive for FSHD1 (9 out of 308 samples)
The overall diagnostic yield of OGM and NGS combined was 58% (317 out of 547 samples)
“Bionano Laboratories has developed a powerful menu of OGM-based LDTs, including one LDT for FSHD1 diagnosis. We are pleased to see this prestigious group of researchers’ findings from the largest FSHD study to date utilizing OGM. Using the study’s algorithm, researchers may be able to diagnose most cases of FSHD, underscoring OGM’s potential to contribute to diagnosis of the disorder, which may lead to better disease management and outcomes,” commented Justin Leighton, vice president of laboratory business at Bionano Laboratories