April 12, 2025 – (The Times) – A simple £80 blood test could detect Parkinson’s disease before full-blown symptoms emerge, a study suggests.
The hope is that earlier diagnoses will allow for better treatment of the degenerative condition, which affects about 153,000 people in the UK.
Parkinson’s is caused by a loss of nerve cells in a part of the brain called the substantia nigra. This leads to a reduction in dopamine, a chemical that plays an important part in controlling movement.
Patients can be treated with dopamine replacement therapies but only after the onset of symptoms, which can include tremors, rigidity, slowness of movement and mood and memory problems.
Scientists believe that spotting the disease at a much earlier stage could allow for the administration of drugs that protect the dopamine-producing brain cells, thereby slowing or even potentially preventing the disease.
The new test looks for small pieces of genetic material known as transfer RNA fragments (tRFs) in the blood, focusing on a repetitive sequence that accumulates in Parkinson’s patients. It also looks for a decline in RNA from mitochondria, which exist inside cells and generate energy.
By measuring the ratio between the two, the test was able to distinguish between samples taken from healthy individuals and Parkinson’s patients who had only very subtle symptoms, such as mood issues, which often go unnoticed.
On a scale where a score of 1 would indicate a perfect test and 0.5 would show that a test is no better than tossing a coin, it scored 0.86. That was better than the best clinical tests used at present on patients showing early signs of the disease, which scored 0.73, according to a study published in the journal Nature Aging.
The new test uses the same polymerase chain reaction (PCR) technology that laboratories used during the pandemic to confirm Covid cases. It works by amplifying the specific genetic material being targeted, allowing it to be detected.
The study also found that the levels of the transfer RNA fragments targeted by the test decreased following deep brain stimulation, a treatment used to alleviate the symptoms of Parkinson’s.
“This discovery represents a major advancement in our understanding of Parkinson’s disease and offers a simple, minimally invasive blood test as a tool for early diagnosis,” said Professor Hermona Soreq of the Hebrew University of Jerusalem, who oversaw the research.
“By focusing on tRFs, we’ve opened a new window into the molecular changes that occur in the earliest stages of the disease.”