Blood test may detect motor neurone disease up to a decade before symptoms, study suggests

Researchers at the Johns Hopkins University School of Medicine say a simple blood test can identify patients who will develop motor neurone disease years before symptoms appear, a finding that could change how the condition is detected and studied.

The team reported that specific proteins in blood samples distinguished people who later developed amyotrophic lateral sclerosis, the most common form of motor neurone disease, up to about a decade before clinical symptoms were evident. "We had always assumed that ALS was a rapid disease that starts 12 to 18 months before symptom onset," said Professor Alexander Pantelyat, an investigator on the study. "But when we look at our findings, we see this has been a process that goes on for a decade or so before the patient ever steps into the doctor's office or clinic." Motor neurone disease is rare and incurable; it affects the brain and nerves, progressively robbing patients of the ability to move, eat and eventually breathe.

The investigators said the protein signatures they measured could form the basis of a readily available blood test. "We see the light at the end of the tunnel here, and that target is an approved and available blood test for ALS," Pantelyat said. The researchers and outside specialists said earlier detection could permit clinical trials and interventions to begin before the disease becomes severely debilitating, potentially improving the chances of meaningful benefit from treatments developed in the future.

The findings alter a prevailing view of the disease's timeline. Historically, ALS and related motor neurone diseases have been seen as conditions with rapid clinical onset, with symptoms appearing and progressing over months to a few years. The Johns Hopkins team's results suggest a longer, preclinical phase during which biological changes accumulate and might be detectable by blood-based biomarkers.

Study authors cautioned that additional research is required before any test based on these markers could be used widely in clinical practice. Larger and more diverse cohorts will be needed to validate the protein signatures, determine how early they can reliably predict disease, and assess how test results should inform patient care and trial enrollment. The investigators also noted that ethical, logistical and medical considerations would have to be addressed before routine screening could be recommended.

Neurology specialists said the research is important because a validated blood test would provide a practical tool for enrolling people at the earliest stages into prevention and treatment studies, rather than waiting for symptom onset. That shift could accelerate understanding of disease mechanisms and the development of therapies.

While the prospect of a predictive blood test has drawn cautious optimism, clinicians emphasized that ALS remains a life-threatening condition with no cure. The Johns Hopkins findings represent a potential advance in early detection and research strategy, but further validation and regulatory review will be necessary before the test can be adopted in routine clinical care.