Revolutionary Parkinson's Blood Test Detects Disease Before Tremors

Long before Parkinson’s disease shows itself in the form of horrific symptoms, quiet biological changes may already be visible in the blood, opening a narrow window for earlier action. New research suggests a low-cost blood test can identify the disease with notable accuracy even before classic symptoms begin to surface. Early Parkinson’s clues in blood The approach centers on measuring specific RNA patterns in blood samples, which researchers found differed consistently between people with early Parkinson’s changes and those without the disease. Scientists at the Hebrew University of Jerusalem (HUJI) built the blood test by seeking changes that appear before a doctor sees Parkinson’s signs. The work was led by Professor Hermona Soreq at HUJI in Jerusalem, where her team studies early disease signals. Her laboratory studies how gene activity and molecular signals shape brain function, including changes that build across aging and disease. That focus matters because early biological changes can outpace what a short office exam can capture during routine visits. The years before tremors Parkinson’s can start with sleep problems, constipation, or smell loss, long before a tremor becomes hard to ignore. Cells in the substantia nigra, a midbrain region that makes dopamine, slowly fail, which weakens movement control. Doctors look for tremor, slowness, and stiffness, yet these signs can overlap with medication effects or other disorders. Earlier detection could help people plan and join trials, but it also raises hard choices about testing when treatments remain limited. Genetic Parkinson’s clues in blood Researchers looked for a biomarker, a measurable body signal linked to disease, that stays stable across many people. They settled on transfer RNA fragments, or tRFs, which are short RNA pieces cut from transfer RNA and show repeatable patterns across samples. “By focusing on tRFs, we’ve opened a new window into the molecular changes that occur in the earliest stages of the disease,” said Soreq. Comparing two fragment families in a ratio can reduce noise from sample concentration and highlight a disease-linked pattern across samples. How the lab reads genetic signals Technicians extract RNA from whole blood, then target the chosen fragments for amplification during testing. The process uses polymerase chain reaction, a method that copies selected genetic sequences many times, until detectors can measure them. By running two reactions side by side, the blood test outputs a single ratio that reflects both rising and falling signals. Labs already use this approach for many infections, but Parkinson’s screening would still demand strict controls and careful interpretation. Putting performance to the test To judge whether the ratio works before diagnosis, the team compared blood results from at-risk volunteers and matched controls. Symptom-based scoring reached 0.73 on the same one-point scale, and the blood test performed better in that comparison. In one dataset, the researchers trained a computer model on 60 people in an early-risk group and 60 controls. Those numbers show promise, yet a few unusual subgroups in the data did not separate cleanly, and that limits confidence. Why fragments might matter Beyond diagnosis, the same RNA fragments could also hint at what changes inside cells as Parkinson’s progresses. Lab tests suggest some tRFs may disrupt translation, the cell step that turns RNA instructions into protein, by binding protein-making machinery. The team found signs that the Parkinson’s-linked motif sticks tightly to key RNA components, which could slow protein production under stress. Researchers still need to prove this mechanism in human brain tissue, so the blood test should not be treated as a direct explanation. Signals respond to stimulation Some participants had already received deep brain stimulation. This surgically implanted system delivers electrical pulses to calm hard-to-control tremor. After treatment, researchers saw lower levels of the repeating-sequence tRF family in blood than in similar patients without implants. Cell experiments that mimicked electrical depolarization also reduced how much of that tRF family stayed attached to protein-making machinery. The link suggests the marker tracks biology that responds to stimulation, yet the study did not show whether changing it improves disease. Why screening is difficult Before any screening reaches clinics, researchers must test the blood ratio in much larger groups and in everyday settings. True validation means tracking the same people over time, then checking whether those with high scores later develop clear Parkinson’s. Clinicians also need proof that the marker stays specific when early symptoms come from other movement or sleep disorders. Without that work, a positive result could trigger anxiety and extra tests, while a negative result could provide false reassurance. Future of Parkinson’s blood tests In the United Kingdom alone, around 166,000 people live with Parkinson’s and numbers keep climbing as the population ages. A reliable blood test could route high-risk people to specialist visits and research trials earlier, when symptoms still barely interfere. Researchers developing disease-slowing therapies often struggle to enroll patients soon enough, so early identification could speed better testing. Health systems would also need clear rules for counseling, follow-up, and privacy, since a blood score can change how insurers view risk. The new research links a simple ratio of RNA fragments to early Parkinson’s biology and measurable changes in blood. Large, diverse validation studies will decide whether the blood test becomes a routine screen or remains a research-only signal. The study is published in Nature Aging. —– Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates. Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com. —–