Parkinson DiseaseNCT04553185
Aquaporin-4 Single Nucleotide Polymorphisms in Patients With Idiopathic and Familial Parkinson's Disease
An observational study of Parkinson Disease, run by University of Exeter at 4 sites in United Kingdom.
Trial summary
The purpose of this study is to understand the relationship between problems in sleep, genetic variations in the Aquaporin-4 gene (AQP4), and the development of Parkinson's Disease. Read more about this study
- Who is it for?
- Ages 18 to 85 years
- Conditions the study is for
- Parkinson Disease
- What is being tested?
- Study procedure
- How many people
- 733 participants
- Where
- 4 sitesUnited Kingdom
- Study dates
- 28 Nov 2018to 30 Apr 2026
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 85 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Patients with a diagnosis of Parkinson's disease according to Published Criteria.
Who may be able to join
- 18-85 years of age
- Able to give informed consent
- Able to perform online neuropsychological examinations
- Diagnosis of PD according to Brain Bank Criteria
- No presence or personal or family history of other neurological or psychiatric disorders
Who cannot join
- Presence of other neurological disorders and known intracranial co-morbidities such as stroke, haemorrhage, space-occupying lesions
- Inability to perform online neuropsychological assessment
- Inability to have access to informatics technology to perform the online assessment tests
- Inability to travel for the assessments
- Native language different from English
Trial locations and contacts
4 sites in 1 country.
United Kingdom4 sites
East Kent University Hospitals NHS Foundation Trust
Ashford
University of Exeter
Exeter, SE16 7RJ
Prince Phillip Hospital
Llanelli
Lewisham and Greenwich NHS Foundation Trust
London
About this study
Official title: Study on the Effects of Single Nucleotide Polymorphisms in Aquaporin-4 (AQP4) Gene on the Clinical Phenotype in Patients With Idiopathic and Familial Parkinson's Disease.
The purpose of this study is to understand the relationship between problems in sleep, genetic variations in the Aquaporin-4 gene (AQP4), and the development of Parkinson's Disease.
Read the detailed description
Parkinson's Disease (PD) is a progressive neurodegenerative disease characterized by the abnormal deposition in the brain of aggregates called Lewy Bodies, packed with a protein called α-synuclein. The mechanisms why this protein accumulates in the brain of patients with PD, as well as its relationship with clinical symptoms, is unknown.
Recently, an internal mechanism of drainage of waste proteins called glymphatic system has been identified and characterized. This system is silent during wakefulness and works during sleep. When it is active, a virtual space between the blood capillaries and cells of the brain called astrocytes opens and lets out waste products from the brain. This process is mediated by a protein of the astrocytes called Aquaporin-4 (AQP4). Preclinical studies have shown that the function of this system could be critical for the clearance of β-amyloid, a protein linked with the development of Alzheimer's Disease. Studies in humans have shown that genetic variations some parts of the AQP4 gene, defined as single nucleotide polymorphisms, may increase the likelihood to develop an aggressive form of Alzheimer's Disease. However, no studies in humans have ever been performed in Parkinson's disease and α-synuclein.
In this study, the investigators aim to elucidate whether genetic variations in the AQP4 gene contribute to variations in the clinical presentation and progression of sporadic and genetic forms of Parkinson's disease. To do so, the genetic profile of patients will be determined through a small venous blood sample collection. This will be coupled with clinical and sleep assessment.
- Conditions
- Parkinson Disease
- Being tested
- Study procedure
- Keywords
- Parkinson's disease, AQP4, Glymphatic System, Genetics
- Medical subject headings
- Parkinson Disease
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Study procedureOther
All participants will undergo a collection of demographic data, personal and family history for PD, a neurological examination and administration of clinical scales. All participants will undergo a collection of venous blood sample. At the end of the visit they will receive a wristwatch to monitor their sleep at home (Actigraph) and a sleep diary, together with a prepaid envelope to post the watch and the diary back to the investigators. They will also receive a link for a series of online tests for non-motor symptoms related to Parkinson's disease that they can complete remotely at home.
| Study group | Role | What they receive |
|---|---|---|
| Parkinson's disease patients | Patients with idiopathic or familial Parkinson's disease Receives: Other: Study procedure |
What is being measured
The primary outcome is the main question the study is designed to answer.
Association between genetic variations in the AQP4 gene and worse motor symptoms in PD patients
The presence of genetic variations in the AQP4 gene, measured with single nucleotide polymorphisms will be correlated, in idiopathic and familial PD patients, with higher (worse) scores on the Hoehn \& Yahr scales
Measured: Up to 36 months
Association between genetic variations in the AQP4 gene and worse cognitive symptoms in PD patients
The presence of genetic variations in the AQP4 gene, measured with single nucleotide polymorphisms will be correlated, in idiopathic and familial PD patients, with lower (worse) scores on Montreal Cognitive Assessment (MoCA) scale
Measured: Up to 36 months
Association between genetic variations in the AQP4 gene and worse sleep symptoms in PD patients
The presence of genetic variations in the AQP4 gene, measured with single nucleotide polymorphisms will be correlated, in idiopathic and familial PD patients, with worse sleep performances as assessed with sleep scales and Actigraph
Measured: Up to 36 months
Association between genetic variations in the AQP4 gene and worse non-motor symptoms in PD patients
The presence of genetic variations in the AQP4 gene, measured with single nucleotide polymorphisms will be correlated, in idiopathic and familial PD patients, with higher (worse) scores on scales for non-motor symptoms.
Measured: Up to 36 months
Secondary outcomes (3)
Association between genetic variations in the AQP4 gene and altered levels of glymphatic system markers in PD patients
The presence of genetic variations in the AQP4 gene, measured with single nucleotide polymorphisms will be correlated, in idiopathic and familial PD patients, with increased levels of blood concentration of LRP-1, ABCB1 and AQP4
Measured: Up to completion of study
Association between genetic variations in the AQP4 gene and altered levels of astrocytic
The presence of genetic variations in the AQP4 gene, measured with single nucleotide polymorphisms will be correlated, in idiopathic and familial PD patients, with increased levels of blood concentration of S100β
Measured: Up to completion of study
Association between genetic variations in the AQP4 gene and altered levels of protein aggregation markers in PD patients
The presence of genetic variations in the AQP4 gene, measured with single nucleotide polymorphisms will be correlated, in idiopathic and familial PD patients, with increased levels of blood concentration of α-synuclein
Measured: Up to completion of study
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted17 Sep 2020
- Study start28 Nov 2018
- Primary completion30 Apr 2026
- Study completion30 Apr 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Parkinson DiseaseStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Cross-sectional
- Enrolment
- 733 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Exeter
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Marios Politis, MD MSc PhD, Study chair, University of Exeter
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04553185
- Sponsor's protocol ID
- 2020 21/02
- Status last verified
- Oct 2025
- First submitted
- 26 Aug 2020
- Last updated
- 18 May 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: There is no plan to share IPD with other researchers.
Study at a glance
From the registry record, last updated by the sponsor on 18 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Study on the Effects of Single Nucleotide Polymorphisms in Aquaporin-4 (AQP4) Gene on the Clinical Phenotype in Patients With Idiopathic and Familial Parkinson's Disease.
- ClinicalTrials.gov ID
- NCT04553185
- Acronym / sponsor ID
- 2020 21/02
- Conditions
- Parkinson Disease
- Keywords
- Parkinson's disease, AQP4, Glymphatic System, Genetics
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 733 participants (actual)
- Lead sponsor
- University of ExeterUniversity, hospital or other
- Study start
- 28 Nov 2018 (actual)
- Primary completion
- 30 Apr 2026 (actual)
- Study completion
- 30 Apr 2026 (actual)
- First posted
- 17 Sep 2020 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of this study is to understand the relationship between problems in sleep, genetic variations in the Aquaporin-4 gene (AQP4), and the development of Parkinson's Disease.
Detailed description
Parkinson's Disease (PD) is a progressive neurodegenerative disease characterized by the abnormal deposition in the brain of aggregates called Lewy Bodies, packed with a protein called α-synuclein. The mechanisms why this protein accumulates in the brain of patients with PD, as well as its relationship with clinical symptoms, is unknown.
Recently, an internal mechanism of drainage of waste proteins called glymphatic system has been identified and characterized. This system is silent during wakefulness and works during sleep. When it is active, a virtual space between the blood capillaries and cells of the brain called astrocytes opens and lets out waste products from the brain. This process is mediated by a protein of the astrocytes called Aquaporin-4 (AQP4). Preclinical studies have shown that the function of this system could be critical for the clearance of β-amyloid, a protein linked with the development of Alzheimer's Disease. Studies in humans have shown that genetic variations some parts of the AQP4 gene, defined as single nucleotide polymorphisms, may increase the likelihood to develop an aggressive form of Alzheimer's Disease. However, no studies in humans have ever been performed in Parkinson's disease and α-synuclein.
In this study, the investigators aim to elucidate whether genetic variations in the AQP4 gene contribute to variations in the clinical presentation and progression of sporadic and genetic forms of Parkinson's disease. To do so, the genetic profile of patients will be determined through a small venous blood sample collection. This will be coupled with clinical and sleep assessment.
Study design
- Observational model
- Cohort
- Time perspective
- Cross-sectional
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Parkinson's disease patients | – | Other: Study procedurePatients with idiopathic or familial Parkinson's disease |
Who may qualify
- Ages
- 18 to 85 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Patients with a diagnosis of Parkinson's disease according to Published Criteria.
Key inclusion criteria (5 listed)
- 18-85 years of age
- Able to give informed consent
- Able to perform online neuropsychological examinations
- Diagnosis of PD according to Brain Bank Criteria
- No presence or personal or family history of other neurological or psychiatric disorders
Key exclusion criteria (5 listed)
- Presence of other neurological disorders and known intracranial co-morbidities such as stroke, haemorrhage, space-occupying lesions
- Inability to perform online neuropsychological assessment
- Inability to have access to informatics technology to perform the online assessment tests
- Inability to travel for the assessments
- Native language different from English
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Study procedureAll participants will undergo a collection of demographic data, personal and family history for PD, a neurological examination and administration of clinical scales. All participants will undergo a collection of venous blood sample. At the end of the visit they will receive a wristwatch to monitor their sleep at home (Actigraph) and a sleep diary, together with a prepaid envelope to post the watch and the diary back to the investigators. They will also receive a link for a series of online tests for non-motor symptoms related to Parkinson's disease that they can complete remotely at home. | Other | Parkinson's disease patients |
Primary outcome
Association between genetic variations in the AQP4 gene and worse motor symptoms in PD patients
Time frame: Up to 36 months
The presence of genetic variations in the AQP4 gene, measured with single nucleotide polymorphisms will be correlated, in idiopathic and familial PD patients, with higher (worse) scores on the Hoehn \& Yahr scales
Association between genetic variations in the AQP4 gene and worse cognitive symptoms in PD patients
Time frame: Up to 36 months
The presence of genetic variations in the AQP4 gene, measured with single nucleotide polymorphisms will be correlated, in idiopathic and familial PD patients, with lower (worse) scores on Montreal Cognitive Assessment (MoCA) scale
Association between genetic variations in the AQP4 gene and worse sleep symptoms in PD patients
Time frame: Up to 36 months
The presence of genetic variations in the AQP4 gene, measured with single nucleotide polymorphisms will be correlated, in idiopathic and familial PD patients, with worse sleep performances as assessed with sleep scales and Actigraph
Association between genetic variations in the AQP4 gene and worse non-motor symptoms in PD patients
Time frame: Up to 36 months
The presence of genetic variations in the AQP4 gene, measured with single nucleotide polymorphisms will be correlated, in idiopathic and familial PD patients, with higher (worse) scores on scales for non-motor symptoms.
3 secondary outcomes
Association between genetic variations in the AQP4 gene and altered levels of glymphatic system markers in PD patients
Time frame: Up to completion of study
Association between genetic variations in the AQP4 gene and altered levels of astrocytic
Time frame: Up to completion of study
Association between genetic variations in the AQP4 gene and altered levels of protein aggregation markers in PD patients
Time frame: Up to completion of study
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 18 May 2026.
- Individual participant dataSharing planned: No. There is no plan to share IPD with other researchers.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Marios Politis, MD MSc PhD study chair
University of Exeter
4 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Parkinson Disease, run by University of Exeter at 4 sites in United Kingdom.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 18 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 4 sites in United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Association between genetic variations in the AQP4 gene and worse motor symptoms in PD patients (time frame: Up to 36 months). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 18 May 2026.