Skin biopsy test for phosphorylated alpha‑synuclein to find which essential tremor patients are at risk for Parkinson's disease

Analysis of Cutaneous Phosphorylated Alpha-Synuclein to Identify Patients at Risk of Progressing From Essential Tremor to Parkinson's Disease

Observational CND Life Sciences · NCT07428447

This uses a small skin biopsy (Syn‑One) to see if phosphorylated alpha‑synuclein can identify people aged 50–85 with essential tremor who are more likely to develop Parkinson's disease.

Quick facts

Study typeObservational
Enrollment300 (estimated)
Ages50 Years to 85 Years
SexAll
SponsorCND Life Sciences Academic / other
Locations1 site (Scottsdale, Arizona)
Trial IDNCT07428447 on ClinicalTrials.gov

What this trial studies

This observational protocol enrolls people aged 50–85 with essential tremor or ET‑Plus and collects small cutaneous biopsies to test for phosphorylated alpha‑synuclein using the Syn‑One assay. Participants receive baseline clinical characterization and longitudinal follow‑up to see which biomarker‑positive individuals later develop Parkinsonian features. The aim is to identify a subgroup of ET patients with underlying synucleinopathy and to develop predictors of phenoconversion without relying on costly or invasive imaging. The work is conducted at the CND Clinical Research Center in Scottsdale, Arizona and does not involve investigational drug treatments.

Who should consider this trial

Good fit: Adults aged 50–85 with a diagnosis of essential tremor or ET‑Plus by 2018 MDS criteria who can consent and are willing to undergo a skin biopsy and follow‑up visits are ideal candidates.

Not a fit: People under 50 or over 85, those with clear clinical parkinsonism or severe peripheral vascular disease preventing safe skin biopsy, or those unwilling to undergo biopsy or follow‑up are unlikely to benefit.

Why it matters

Potential benefit: If successful, this could allow earlier identification of ET patients at high risk of developing Parkinson's disease so they can receive closer monitoring and earlier intervention.

How similar studies have performed: Post‑mortem and small skin‑biopsy studies have detected phosphorylated alpha‑synuclein in some patients with tremor and prodromal Parkinson's, but prospective prediction of conversion is still only partially validated.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Age 50-85 years old
* Diagnosis of ET as defined by the 2018 MDS Task force paper "1) isolated tremor syndrome of bilateral upper limb action tremor 2) at least 3 years' duration 3) with or without tremor in other locations (e.g., head, voice, or lower limbs) 4) absence of other neurological signs, such as dystonia, ataxia, or parkinsonism." OR
* Diagnosis of ET-Plus as stated by the 2018 MDS Task force paper, "Tremor with the characteristics of ET and additional neurological signs of uncertain significance such as impaired tandem gait, questionable dystonic posturing, memory impairment, or other mild neurologic signs of unknown significance that do not suffice to make an additional syndrome classification or diagnosis. ET with tremor at rest should be classified here."
* Willing to participate in all study procedures
* Able and willing to provide written informed consent

Exclusion Criteria:

* Under age 50, Over age 85
* Clinical evidence of severe peripheral vascular disease
* Clinically active coronary artery or cerebrovascular disease
* Participant is currently on anticoagulant or dual anti-platelet therapy
* Alcoholism
* Allergic reaction to local anesthesia
* History of or increased risk for impaired wound healing, scarring, or keloid formation
* Diagnosis of ET or ET-Plus that is clinically determined to likely be secondary to brain injury or vascular compromise
* History of other neurodegenerative disorder or evidence of neurological co-pathology
* Abnormal DaTscan
* Participant is currently receiving treatment with carbidopa-levodopa for PD
* Isolated focal tremors (head, voice)
* Task-specific tremor (e.g., primary writing tremor)
* Position-specific tremors that does not otherwise meet clinical diagnostic criteria for ET
* Sudden onset and step-wise deterioration

Where this trial is running

Scottsdale, Arizona

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Essential Tremor, Movement DisordersEssential TremorEssential Tremor-plusskin biopsySyn-One
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.