Researchers led by a team from Duke Health have developed a blood test to detect Parkinson’s disease, which afflicts 10 million people globally and is the second most common neurodegenerative disorder. The illness causes unintended or uncontrollable movements, such as shaking, stiffness and difficulty with balance and coordination. Symptoms start slowly and worsen over time.

Until now, diagnosing Parkinson’s relied on a person’s medical history, a neurological examination and observable symptoms. An accurate diagnosis is critical because there are other disorders with Parkinson’s-like symptoms that require different treatments.

The Duke Health blood test focuses on DNA damage in mitochondria, the energy-converting factories within cells. Patients with Parkinson’s had higher levels of mitochondrial DNA damage in blood cells, as compared to patients without the disease. The test also detects specific genetic mutations that are associated with an increased risk of the disease, which may be able to help doctors predetermine whether certain therapies would be effective on their patients. Researchers hope the new blood test will not only diagnose Parkinson’s disease, but also identify drugs that reverse or halt mitochondrial DNA damage and the disease process.