Blood test shows promise for earlier motor neurone disease diagnosis with 97% accuracy

A new blood test developed by Brain Chemistry Labs can detect motor neurone disease, also known as ALS, in its earliest stages with about 97% accuracy, including before symptoms appear, according to researchers. In a study of 788 blood samples — roughly half from people with the disease and half from those without it — scientists focused on eight microRNAs, tiny fragments of genetic material in the blood that help regulate cellular functions. The team established biomarker parameters using 449 samples and then used a laboratory technique called quantitative polymerase chain reaction, or qPCR, to rapidly analyse the remaining samples and gauge how accurately the test could diagnose the condition. The test correctly identified patients with motor neurone disease 97% of the time and correctly ruled out the illness in 93% of those without it.

Researchers say that diagnosing ALS earlier could let patients start therapies sooner and access specialist care, symptom-relief strategies and clinical trials at a point when the disease is less advanced. The test’s authors emphasize that early detection could address one of the field’s biggest obstacles: substantial delays between symptom onset and an official diagnosis. In ALS, where life expectancy after symptoms typically ranges from two to five years, even a year-long diagnostic delay can have meaningful consequences for patient care and planning.

The work was led by researchers at the non-profit Brain Chemistry Labs in the United States. They say the eight microRNAs identified appear to form a distinctive signature for motor neurone disease, offering a molecular clue that could be measured in a person's blood without invasive procedures. The next step, according to the team, is to move the test beyond the laboratory setting by partnering with a diagnostic company to bring a commercial version to market. The group notes that an approved test could allow clinicians to initiate therapy earlier in the disease course and to enroll suitable patients in clinical trials that target the underlying biology of ALS.

The findings were presented at the International Symposium on ALS/MND last week and published in Molecular Neurobiology. The researchers caution that more work is needed to validate the test across broader populations and to confirm performance in real-world clinical settings, but they say the results are encouraging for a field where diagnostic delays are common and where timely access to care can influence outcomes.

In addition to the main study, scientists have recently pursued genetic angles to understand why motor neurone disease develops. A separate study published earlier this year identified 423 ultra-rare genetic variants shared by people with ALS and another motor neuron condition, hereditary spastic paraplegia. The researchers, including statistician Gang Wu, analysed a large dataset spanning related motor neuron disorders and found that rare variants in certain genes linked to hereditary spastic paraplegia could also increase the risk for sporadic ALS. The team suggests that these overlaps may illuminate shared biological pathways and support the search for new treatments that could affect multiple motor neuron diseases.

The condition has drawn public attention as several high-profile figures have disclosed diagnoses in recent years. England rugby union former star Lewis Moody revealed he had been diagnosed with motor neurone disease at the age of 47, underscoring the impact of the disease on lives outside the clinic. The illness has also claimed the life of former rugby league player Rob Burrow, who was diagnosed in 2019 and became a prominent advocate for research funding and improved care. In entertainment and science, public notices of ALS diagnoses have helped raise awareness of the urgency of research, even as experts stress that there is currently no cure and that treatments focus on managing symptoms and slowing progression where possible.

Experts say that earlier and more accurate diagnosis could enable patients to access specialist care sooner, participate in clinical trials, and begin palliative and supportive therapies earlier, potentially improving quality of life even if the disease cannot yet be cured. ALS typically affects adults between 55 and 75, with a pattern of steadily worsening muscle weakness, speech difficulties, breathing problems and, in many cases, reduced mobility. While progression rates vary, life expectancy after diagnosis remains a critical concern for patients and families, driving continued emphasis on early identification and the development of targeted therapies.

Overall, the study highlights a growing interest in blood-based biomarkers as a practical route to earlier detection of motor neurone disease. If validated in broader populations and integrated into standard diagnostic workflows, the test could become a widely accessible tool that complements clinical assessment and imaging. Researchers also stress the importance of continued investment in both diagnostics and disease-modifying research to turn earlier identification into tangible improvements in care and outcomes for people living with ALS and related motor neuron conditions.