Screening for the Transthyretin-Related Familial Amyloidotic Polyneuropathy (TTR FAP)

Study Overview
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Brief Summary
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An International, multicenter, epidemiological observational study investigating the prevalence of Transthyretin-Related Familial Amyloidotic Polyneuropathy (TTR-FAP) in participants with small fiber polyneuropathy of no obvious etiology.

Detailed Description
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Transthyretin-related Familial Amyloid Polyneuropathy (TTR-FAP) is an autosomal dominant, progressive neurodegenerative disease, with fatal outcome occurring within ten years after onset. Familial amyloid polyneuropathy (FAP) associated with mutations in the transthyretin (TTR) gene is the most common form of genetic amyloidosis. It accounts several thousand cases worldwide, with Val30Met mutation identified in most patients and with endemic foci in Portugal, Sweden and Japan. TTR FAP is caused by the systemic deposition of amyloidogenic variants of the transthyretin protein ((Ttr) in the extra-cellular space of tissues and result in disruption of organ function.The typical presentation of TTR-FAP is a progressive sensory-motor polyneuropathy, which usually begins with loss of thermal and pain sensation in the feet, slowly ascends up the limbs and is associated with variable autonomic disturbances and extra-neurological manifestations (especially a cardiomyopathy). The goal of the TRAP2.1 Study is to investigate the prevalence of Transthyretin-Related Familial Amyloidotic Polyneuropathy (TTR-FAP) in a cohort of 500 subjects with small fiber polyneuropathy of no obvious etiology, based on the subject's clinical presentation.

Official Title
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Screening for the Transthyretin-Related Familial Amyloidotic Polyneuropathy (TTR-FAP): An International, Multicenter, Epidemiological Protocol

Conditions
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Polyneuropathy, Amyloid, Neuropathic Pain, Cardiac Failure, Orthostatic Hypotension, Gastrointestinal Disorders

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Informed consent is obtained from the participant The participant is aged between 18 and 85 years of age The participant is diagnosed with small fiber polyneuropathy of no obvious etiology The participant has no diagnosis of alcoholism, according to International Guidelines The participant has not undergone chemotherapy for carcinoma Exclusion Criteria: Inability to provide informed consent The participant is younger than 18 years or older than 85 years of age The etiology of the small fiber polyneuropathy is clearly determined The participant has a diagnosis of alcoholism, according to International Guidelines The participant has undergone chemotherapy for carcinoma

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 85 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Participants diagnosed with small fiber polyneuropathy no obvious etiology<br>Participants aged between 18 and 85 years, diagnosed with small fiber polyneuropathy of no obvious etiology, without diagnosis of alcoholism and not undergoing chemotherapy for cancer | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Epidemiological analysis of prevalence of the TTR FAP in participants with small fiber polyneuropathy of no obvious etiology. | Dry Blood Spot (DBS) samples will be genetically validated via combination of Next-Generation Sequencing (the mutation will be confirmed by Sanger sequencing) and the Multiplex ligation-dependent probe amplification (MLPA) of TTR gene | 3 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Establishment of a biomarker in TTR-positive cohort | Samples carrying a mutation in the TTR gene will be biochemically analyzed via liquid chromatography multiple reaction monitoring MS and compared with a merged control cohort, in order to establish TTR mutation-specific biomarker/s. | 3 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Transthyretin-Related (ATTR) Familial Amyloid Polyneuropathy, TTR FAP, Biomarker