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Completed

NCT Number: NCT04553185

Aquaporin-4 Single Nucleotide Polymorphisms 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.

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Key information

Age range

18 year–85 year

Sex eligibility

All sexes

Study type

Observational

Primary location

East Kent University Hospitals NHS Foundation Trust, Ashford, United Kingdom

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About this study

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.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • 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

Exclusion criteria

  • 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

Treatment and study plan

Study procedure

Other

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.

Primary outcomes

  1. 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

  2. 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

  3. 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

  4. 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.

Secondary outcomes

  1. 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

    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

  2. Association between genetic variations in the AQP4 gene and altered levels of astrocytic

    Time frame: Up to completion of study

    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

  3. 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

    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

Sponsors and collaborators

Lead sponsor

University of Exeter

Other

Registry information

Official study 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.

Important dates

Study start
2018
Primary completion
2026
Study completion
2026
First posted
Sep 17, 2020
Registry last updated
May 18, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

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This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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