When Sarah Thompson was finally told at age 42 what had been weakening her muscles since childhood, she cried—not just for herself, but for her father, who had lived 30 years without a diagnosis before passing away. Her answer came from a groundbreaking DNA test developed in Sydney, one that is solving medical mysteries once thought unsolvable. At the Garvan Institute of Medical Research, scientists have created the world’s first test capable of diagnosing inherited muscle diseases missed by standard genetic screening. For people like Sarah, who spent an average of 14 years searching for answers, the test is nothing short of life-changing.
Inherited muscle diseases, such as muscular dystrophies, affect around 6,000 Australians. These conditions slowly erode strength, often making walking, speaking, or swallowing difficult. While they can appear at any age, they share one cruel trait: the lack of a clear diagnosis. Standard tests look for one type of genetic error at a time—like searching for a typo using a magnifying glass. But these diseases can stem from many kinds of DNA changes, from tiny spelling mistakes to large missing sections or repeating sequences. Until now, no single test could catch them all.
The new method, called long-read nanopore sequencing, reads long stretches of DNA in one go. In a single experiment, it scans over 300 genes linked to muscle disease and detects every known kind of genetic flaw. In a study published in Nature Communications, researchers used it on 53 Australians with suspected inherited muscle disorders. Of the 31 who had previously received no diagnosis, more than a third—12 people—finally got answers. Some had variants never before tested for in Australian clinics. Others had been misdiagnosed for years.
"A confirmed genetic diagnosis changes the counseling we can offer families, opens access to supports such as the National Disability Insurance Scheme, prompts monitoring for complications such as heart problems, and allows people to enroll in clinical trials that require a known genetic cause," says Associate Professor Kishore Kumar, a neurologist at Concord Repatriation General Hospital and co-senior author of the study. For families, knowing the cause means understanding risks for future children, ending the cycle of uncertainty.
The impact goes beyond individual patients. By catching new and rare genetic variants, the test also helps scientists discover previously unknown causes of disease. The Garvan team is now working with NSW Health Pathology to make the test part of routine care. If successful, it could become standard across Australia—and adopted worldwide. For thousands living in diagnostic limbo, that future can’t come soon enough.