Amyloid peripheral neuropathy

As a basis of various pathologic conditions, about 40 or more different proteins each can self-aggregate to form the "primary protein" of an amyloid. For example, in amyloid peripheral neuropathies the deposited extracellular amyloid often contains (a) the variable portion of immunoglobulin light chain in some B-lymphocyte dyscrasias, or (b) mutant transthyretin in some autosomal dominant hereditary amyloid neuropathies. 

One type of familial amyloidosis first identified in the Finnish population is caused by deposition of gelsolin (Maury et al., 2000 Maury et al., 2001). This Finnish type familial amyloidosis (FAF) is a hereditable autosomal dominant amyloid polyneuropathy, characterized by corneal lattice dystrophy, progressive cranial and peripheral neuropathy as well as skin changes (Chen et al., 2001 Maury et al., 2001). 

Transthyretin amyloidosis (also called familial amyloid polyneuropathy) is an autosomal dominant syndrome characterized by peripheral neuropathy. This disease results from one of five mutations identified thus far in the gene for transthyretin. Transthyretin is also called prealbumin (although it has no structural relationship to albumin) because it migrates ahead of albumin in standard electrophoresis at pH 8.6. Transthyretin is synthesized in the liver and is a normal plasma protein with a concentration of 20-40 mg/dL. It transports thyroxine and retinol binding protein (Chapter 38). The concentration of transthyretin is significantly decreased in malnutrition and plasma levels are diagnostic of disorders of malnutrition (Chapter 17). 

Occasionally the nervous system becomes involved in myelomatosis, and a number of cases have been reported. The lesions in these patients include compression of neural structures by myeloma tissue or collapsed vertebra, herpes zoster, and amyloid infiltration of the peripheral nervous system. Although uncommon, a peripheral neuromyopathy in which there is no direct involvement of nerves or nerve roots has been reported, but the association of multiple myeloma with neuropathy and osteosclerotic lesion is rarer and even more unusual. Osuntokun et al. (05) has reported such a patient in Africa whose outstanding clinical features were widespread neuromyopathy associated with multiple myeloma, and general-... 

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