Early Diagnosis of TTR Amyloidosis by Use of Molecular Biology

The initial criteria before amendment Inclusion Criteria: * A. Adult (\>50 years old) * Chronic Peripheral neuropathies (progressing since 12 months), * Peripheral neuropathies documentated by ENMG. 1. Chronic polyneuropathy with dysautonomia (orthostatic hypotension) without diabetes 2. Atypical CIDP (situations C, D (even with high protid content on CSF) \& E as defined by the French group for study of CIDP). 3. Disabling neuropathy (gait or balance disorder) 4. Neuropathies with upper limb onset who underwent previously CTS surgery without success. 5. SLA-like syndrome : areflexia with sensory alterations on ENMG. 6: Deterioration of SNAPs' amplitudes on NCS \> 30% in less than6 months by the same NCS laboratory Mandatory : A+B+C one of 1 to 6 Exclusion criteria : * Amyloid deposit characterized on biopsy * Causes of chronic polyneuropathy : Diabetes mellitus, Chronic alcoholic intoxication * CIDP responding to IVIg or corticosteroids (improvement by 1 point of ONLS). * Neuropathy associated with monoclonal gammapathy and i) anti-MAG activity or ii) POEMS syndrome or) CANOMAD syndrome. * Ataxic Neuropathy due to vitamine B12 deficiency * Ataxic Neuropathy due to IgM anti-MAG, * CANOMAD syndrome, * Ganglionopathy by Sjögren's syndrome, or paraneoplastic syndrome with Anti- Hu Antibodies, chemotherapy induced (cis-platine, oxaliplatine). * Positive family history of FAP or FAC * Proven AL amyloidosis The new criteria after amendment New eligibility criteria from the 351st patient: * A. Adults \> 50 years old B1. Progressive axonal polyneuropathy 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) 1. with pure sensitive 2. pure motor 3. . Asymmetrical sensorimotor impairment predominantly in the upper limbs 4. Situations C, D, E -even at high protein content on CSF- and as defined by the French group for the study of CIDP C. Peripheral neuropathy evolving for ≥ 12 months and \< 10 years. D. Peripheral neuropathy documented by abnormal ENMG (Electroneuromyography). And At least one of the following criteria: 1. Chronic polyneuropathy with dysautonomia (orthostatic hypotension) 2. Disabling neuropathy (walking or balance disorders, functional impairment of the hands) 3. Unintentional weight loss of \> 5 kg in the last 5 years 4. History of operated carpal tunnel syndrome 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 * with Ac anti-MAG, * POEMS, CANOMAD, * Ganglionopathy linked to Gougerot Sjögren's syndrome, to a paraneoplastic syndrome with Anti-Hu antibodies), F. Family history of FAP or FAC (familial amyloid neuropathy or cardiomyopathy) G. AL Amyloidosis