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.
Description: Rate of amyloidogenic TTR mutation in progressive idiopathic polyneuropathy
Measure: Rate of amyloidogenic TTR mutation Time: 1 dayDescription: Rate of amyloidogenic TTR mutation in different subgroups of patients with neuropathy : disabling neuropathy (including ataxic).
Measure: To identify the rate of amyloidogenic TTR mutation in different subgroups of patients with neuropathy Time: 1 dayDescription: Rate of amyloidogenic TTR mutation in different subgroups of patients with neuropathy :variant Chronic Inflammatory Demyelinating Polyneuropathy (CIDP)
Measure: To identify the rate of amyloidogenic TTR mutation in different subgroups of patients with neuropathy :variant Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) Time: 1 dayDescription: Rate of amyloidogenic TTR mutation in different subgroups of patients with neuropathy : upper limb onset neuropathy.
Measure: To identify the rate of amyloidogenic TTR mutation in different subgroups of patients with neuropathy : upper limb onset neuropathy. Time: 1 dayCohort
There is one SNP
Conversely to endemic areas, look for V30M mutation is not enough to exclude TTR-FAP, TTR gene sequencing is required. --- V30M ---