An observational study in Polyneuropathy, Diagnosis and Idiopathic Progressive Neuropathy, sponsored by Assistance Publique - Hôpitaux de Paris. Completed at 10 sites in France. Open to participants aged 51 Years and older. Per ClinicalTrials.gov, last updated 2022-12-08.
Sponsored by Assistance Publique - Hôpitaux de Paris · Observational
Peripheral neuropathies are diseases that affect the nervous system outside the brain and spinal cord, their prevalence is 1% in the general population, the causes are extremely varied with more than 200 identified causes; the main ones are diabetes, excessive alcohol consumption and chemotherapy. They may be sometimes disabling but generally preserve autonomy.
Transthyretin amyloidosis is a rare multisystematic hereditary disease with autosomal dominant transmission. They present usually as a peripheral neuropathies (FAP). They are due to a point mutation of the transthyretin gene (chr 18q). FAP is secondary to endoneurial amyloid deposits and are characterized by a slowly progressive sensory, motor and autonomic. FAP is the most severe hereditary polyneuropathy of the adult are irreversible and fatal within 5 to 12 years from onset.
Most frequent mutation of TTR gene is located on the second exon; but more than 100 mutations have been reported.
Prevalence of FAP is 1 per 1 million inhabitants. They have been reported until 1990s' in four endemic areas North of Portugal, Sweden, Japan and Majorca. In these areas, diagnosis is facilitated because of the stereotypical presentation : a length-dependent polyneuropathy with predominant involvement of thermal and pain sensations and autonomic dysfunction, early onset in the third decade and a predominant Met30 TTR mutation. Positive family history is frequent 85% (one of the parents is affected). Diagnosis requires detection of TTR mutation by molecular biology (blood sample) and characterization of amyloid deposit on labial salivary gland biopsy.
Study of the TTR gene by complete sequencing; search for amyloidogenic mutations of the TTR gene (according to the site http: // amyloidosismutations.com / mut-attr.php) in the laboratory of molecular biology of the CHU BICÊTRE (APHP) managed by Pr Anne Mantel.
Preselection of the cases to be tested among the cases of peripheral neuropathies of indetermined cause referred via the network Cornamyl of which the reference centers of the neuromuscular diseases are belonging .
Currently, FAP is a worldwide disease. Diagnosis of TTR-FAP is extremely difficult and usually delayed by 4 years in non endemic areas for many reasons :
Conversely to endemic areas, look for V30M mutation is not enough to exclude TTR-FAP, TTR gene sequencing is required.
With the help of the french network for FAP (Cornamyl), cases have been identified in 81/100 geographical departments, with a wide genetic heterogeneity (41 mutations reported) ; age of onset is late: 75% after 50 yo.
133 studies on the registry are indexed under Polyneuropathies; 33 are open to participants now.
This study's enrollment of 560 is above the median of 100 across 53 observational studies indexed under Polyneuropathies.
Browse Polyneuropathies studies →Assistance Publique - Hôpitaux de Paris is the lead sponsor of 3,592 studies on the registry; 1,033 are open to participants now.
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Multicentric prospective population in tertiary referal center for neuromuscular diseases
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
The initial criteria before amendment
Inclusion Criteria:
Peripheral neuropathies documentated by ENMG.
Exclusion criteria :
The new criteria after amendment New eligibility criteria from the 351st patient:
Has:
Deterioration of EMG sensory potentials >30% in less than 6 months by the same electrophysiology team Where -. Clinical worsening over 6 months, i.e. + 1 ONLS point, or extension of sensory disorders (subjective, objective), or reduction in walking distance, or JAMAR -10% OR B2. Atypical chronic polyradiculoneuritis (CIDP)
And
At least one of the following criteria:
Exclusion criteria A. Amyloid deposit characterized by biopsy B. Causes of chronic polyneuropathy: sensory neuropathy typical of diabetes mellitus, chronic alcohol intoxication (women: >14 drinks/week; men >21 drinks/week), vitamin B12 deficiency, chemotherapy (cis-Platin, oxaliplatin) C. CIDP responding to IVIG or corticosteroids (1 point improvement in ONLS) D. Peripheral neuropathy evolving for >10 years E. Dysimmune neuropathy defined by
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Biopsy and archival tissue
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Rate of amyloidogenic TTR mutation
Rate of amyloidogenic TTR mutation in progressive idiopathic polyneuropathy
Time frame: 1 day
To identify the rate of amyloidogenic TTR mutation in different subgroups of patients with neuropathy
Rate of amyloidogenic TTR mutation in different subgroups of patients with neuropathy : disabling neuropathy (including ataxic).
Time frame: 1 day
To identify the rate of amyloidogenic TTR mutation in different subgroups of patients with neuropathy :variant Chronic Inflammatory Demyelinating Polyneuropathy (CIDP)
Rate of amyloidogenic TTR mutation in different subgroups of patients with neuropathy :variant Chronic Inflammatory Demyelinating Polyneuropathy (CIDP)
Time frame: 1 day
To identify the rate of amyloidogenic TTR mutation in different subgroups of patients with neuropathy : upper limb onset neuropathy.
Rate of amyloidogenic TTR mutation in different subgroups of patients with neuropathy : upper limb onset neuropathy.
Time frame: 1 day
Ran from Mar 2017 to primary completion in Sep 2021, 54 months.
Of 26 observational studies under Polyneuropathies, half reached primary completion within 54 months of starting (the median), counting those still running; a quarter within 26 and three quarters within 93. This study's 54 months is close to that.
How these figures are worked out, and which studies are left out of them.
This study is completed, as verified in Nov 2022. You cannot join it, but the record below documents what was studied.
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