The Natural History of TRPV4 Neuropathy
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- This is an observational study: the protocol does not assign a study treatment.
- Who it may be relevant to
- Registry conditions: TRPV4 Gene Mutation. Basic parameters: 3 years — 80 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- United States
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Overview
The goal of this research is to document the natural history of neuropathy in patients with a confirmed genetic mutation in the TRPV4 gene. The investigators are searching for patients willing to participate in a 6-year long study to document the symptoms of TRPV4-associated disease and their progression over time. Participation requires annual study visits at Johns Hopkins for adult and juvenile participants.
Detailed description
Genetic variants in the transient receptor potential cation channel subfamily V member 4 (TRPV4) gene are known to cause different forms of inherited neuropathy that can manifest with muscle weakness, sensory loss, and problems with the vocal cords. These different conditions can be referred to as Charcot-Marie-Tooth disease 2C, scapuloperoneal spinal muscular atrophy, or congenital distal spinal muscular atrophy. For unclear reasons, the symptoms vary significantly among the patients, from mild to severe impact and from early childhood onset to adult onset. Research has shown that disease-causing changes in the TRPV4 gene cause overactivation of TRPV4, which could theoretically be treated with a TRPV4 blocking drug.
There have been many case reports about patients with TRPV4-associated disease, but never has there been a large cohort evaluation to study the natural history of the disease to document the frequency and severity of symptoms and how they change over time. Understanding the different sub-types of disease and how they progress over time is essential knowledge to design clinical trials to evaluate the effectiveness of potential treatments.
The investigators are therefore seeking patients with a confirmed mutation in the TRPV4-gene to participate in this research project. It requires annual study visits at Johns Hopkins (Baltimore, Maryland) for adults and pediatric participants. The study is designed to follow patients for six years and testing is scheduled to occur over two days for each visit. Participants will be reimbursed for travel expenses and hotel accommodations, and all tests will be performed free of charge.
Planned testing includes thorough neurological exams, nerve conduction studies, standardized questionnaires, brain MRIs, skeletal X-rays and bone density scans (DEXA), vocal cord and voice assessments, retinal (eye) scans, and a series of tests to evaluate the ability to perform tasks of daily living such as getting up from a chair or walking for six minutes. The investigators will also collect blood samples from each participant to be used for laboratory research.
Primary outcome measures
- Tracking the severity of overall neuropathy symptoms [Time frame: Annually for 6 years]
- Tracking the progression of the disease using functional measures [Time frame: Annually for 6 years]
- Tracking the severity of limitations caused by neuropathy [Time frame: Annually for 6 years]
- Tracking the severity of disease in pediatric patients [Time frame: Annually for 6 years]
Eligibility criteria
Inclusion criteria
- Patient is aged 3-80 years with a documented mutation in the TRPV4 gene and a clinical phenotype consistent with TRPV4-associated disease (as determined by the investigator) OR
- The patient has a first-degree relative (parent, child, sibling, half-sibling, aunt, uncle, grandparent, or grandchild) with a documented disease-causing mutation AND a clear link between that family member and the affected patient AND a clinical phenotype consistent with TRPV4-associated disease.
- Patients with a variant of unknown significance in TRPV4 and a clinical phenotype possibly consistent with TRPV4-associated disease will be eligible for initial enrolment, but continued eligibility will be determined based on whether the observed clinical phenotype is consistent with TRPV4-associated disease (as determined by the investigator).
- Participant or legal guardian for patients under 18 years of age is capable of giving signed informed consent.
Exclusion criteria
- Medical history of other concomitant neurological disease or clinically significant physical exam/laboratory result that, in the opinion of the investigator, would render the patient being unsuitable for the study.
- Patients with a TRPV4 variant of unknown significance who are initially enrolled but then deemed to be unlikely to have a phenotype consistent with TRPV4-associated disease will no longer be eligible and their clinical data will be deleted.
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: No
Study design
- Observational model
- Cohort
Study locations
United States · 1 center
- Johns Hopkins — Baltimore
Identifiers
NCT: NCT05600764 · IRB00341314