Simple Skin Biopsy Shows Promise for Detecting Parkinson’s Disease

Skin test accurately identifies Parkinson’s biomarker, according to new research.

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A simple skin biopsy may hold the key to detecting Parkinson’s disease, according to a new study.

The research has unveiled a minimally invasive test that can identify an abnormal form of the alpha-synuclein protein—the hallmark of Parkinson’s—with remarkable accuracy.

Published in the Journal of the American Medical Association, these findings could revolutionize the diagnosis of a condition that afflicts as many as a million Americans and is expected to affect 1.2 million by 2030.

The Procedure May Be Paving Way for Early Detection

Parkinson’s disease is the second most common neurodegenerative disorder, after Alzheimer’s.

About 200,000 people in the United States face a diagnosis of Parkinson’s, dementia with Lewy bodies, or other related disorders annually, the trial’s lead author, Dr. Christopher Gibbons, a neurologist and a professor of neurology at Harvard Medical School, said in a statement.

Diagnosing Parkinson’s has traditionally been a lengthy process, involving a thorough review of the patient’s history, symptoms, and physical examination. Crucially, there has been no standard lab or imaging test available, forcing doctors to rely on MRI brain scans, dopamine transporter scans, and blood tests.

“Too often, patients experience delays in diagnosis or are misdiagnosed due to the complexity of these diseases,” Dr. Gibbons said. “With a simple, minimally invasive skin biopsy test, this blinded multicenter study demonstrated how we can more objectively identify the underlying pathology of synucleinopathies and offer better diagnostic answers and care for patients.”

The new skin biopsy test could be a game-changer for Parkinson’s and similar neurodegenerative diseases. The four degenerative conditions tested share overlapping features such as tremors and cognitive changes, but Parkinson’s is further characterized by mild memory issues, sleep disturbances, slowness of movement, and pain.

“These are systemic disorders that affect the peripheral and central nervous systems in profound ways,” Dr. Roy Freeman, senior author of the study and professor of neurology at Harvard Medical School, said. “While we have been aware of the presence of alpha-synuclein in cutaneous nerves for many years, we were thrilled with the accuracy of this diagnostic test.”

Skin Biopsy More Than 90 Percent Accurate

The clinical trial involved 428 participants aged 40 to 99 years, each diagnosed with one of four neurodegenerative diseases: Parkinson’s disease, dementia with Lewy bodies, multiple system atrophy, or pure autonomic failure. All participants underwent three 3-millimeter skin punch biopsies taken from the neck, knee, and ankle.

Among those clinically diagnosed with Parkinson’s, 93 percent tested positive for phosphorylated alpha-synuclein, an abnormal protein associated with the condition. The positive rates were even higher for the other disorders: 96 percent for dementia with Lewy bodies, 98 percent for multiple system atrophy, and 100 percent for pure autonomic failure.

“Parkinson’s disease and its subgroup of progressive neurodegenerative diseases show gradual progression, but alpha-synuclein is present in the skin even at the earliest stages,” Dr. Freeman said.

Although encouraged by these findings, the research team acknowledged the need for further work to establish the skin biopsy test’s efficacy. In particular, they suggested testing individuals without clinically diagnosed Parkinson’s or other related conditions. This additional validation would fully confirm the test’s accuracy.