A new long-read DNA test developed by researchers at the Garvan Institute of Medical Research has successfully diagnosed inherited muscle diseases in over a third of patients who spent years or decades without answers after standard testing. Published in Nature Communications, the study applied nanopore sequencing to 53 Australian participants with known or suspected conditions, including 31 whose previous genetic testing had failed to identify a cause.
How Long-Read Nanopore Sequencing Diagnoses Muscle Disease
Standard diagnostic tests for inherited muscle diseases evaluate a single type of DNA change at a time, creating significant blind spots for conditions driven by complex genetic variations. These diseases can stem from single-letter code errors, large missing or duplicated sections, unstable expansions of repeated sequences, or epigenetic chemical marks that alter gene activity. The new approach uses long-read nanopore sequencing to read extended stretches of DNA, screening more than 300 genes associated with inherited muscle disorders in a single experiment. Dr. Ira Deveson, lab head at the Garvan Institute and co-senior author of the study, noted that many muscle diseases lack available genetic tests, while others require separate tests for each individual gene involved. Testing all candidate genes simultaneously eliminates years of sequential, inconclusive procedures for patients.
Practical Consequences of a Confirmed Genetic Diagnosis
Participants in the study had lived without answers for an average of 14 years, enduring blood tests, magnetic resonance imaging scans, neurophysiologic studies, and muscle biopsies. Associate Professor Kishore Kumar, a group leader at Garvan and neurologist at Concord Repatriation General Hospital who co-authored the study, explained that securing a genetic diagnosis alters family counseling options, grants access to support programs like the National Disability Insurance Scheme, initiates monitoring for cardiac complications, and enables enrollment in clinical trials requiring a confirmed genetic cause. Dr. Dennis Yeow, a neurologist and PhD candidate at the University of Sydney who co-led the study, emphasized that providing a definitive name for these conditions carries profound significance for affected individuals and their families.
Timeline for Routine Clinical Implementation
The research team is collaborating with NSW Health Pathology’s Molecular Medicine Laboratory at Concord Hospital to transition the test into routine clinical care. Investigators estimate the diagnostic tool could see deployment across Australia within approximately two years. Dr. Andre Reis, senior research officer and lead bioinformatician at Garvan, built the analytical framework required to convert complex long-read sequencing data into clear, actionable findings for diagnostic laboratories. Looking ahead, the research team aims to adapt this disease-agnostic long-read technology to address other rare inherited conditions that currently leave patients without answers.