The molecular biology and clinical features of amyloid neuropathy

Authors

  • Merrill D. Benson MD,

    Corresponding author
    1. Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, 635 Barnhill Drive, MS-128, Indianapolis, Indiana 46202-5126, USA
    2. Richard L. Roudebush Veterans Affairs Medical Center, Indianapolis, Indiana, USA
    • Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, 635 Barnhill Drive, MS-128, Indianapolis, Indiana 46202-5126, USA
    Search for more papers by this author
  • John C. Kincaid MD

    1. Department of Neurology, Indiana University School of Medicine, Indianapolis, Indiana, USA
    Search for more papers by this author

  • Available for Category 1 CME credit through the AANEM at www.aanem.org.

Abstract

Neuropathy is often a major manifestation of systemic amyloidosis. It is most frequently seen in patients with hereditary transthyretin (TTR) amyloidosis, but is also present in 20% of patients with systemic immunoglobulin light chain (primary) amyloidosis. Familial amyloid polyneuropathy (FAP) is the most common form of inherited amyloidotic polyneuropathy, with clinical and electrophysiologic findings similar to neuropathies with differing etiologies (e.g., diabetes mellitus). Hereditary amyloidosis is an adult-onset autosomal-dominant disease with varying degrees of penetrance. It is caused by specific gene mutations, but demonstration that a patient has one such mutation does not confirm the diagnosis of amyloidosis. Diagnosis requires tissue biopsy with demonstration of amyloid deposits either by special histochemical stains or electron microscopy. Transthyretin amyloidosis is treated by liver transplantation, which eliminates the mutated transthyretin from the blood, but for some patients continued amyloid deposition can occur from wild-type (normal) transthyretin. Presently, a study is ongoing to determine whether amyloid deposition can be inhibited by small organic molecules that are hypothesized to affect the fibril-forming ability of transthyretin. Proposed gene therapy with antisense oligonucleotides (ASOs) to suppress hepatic transthyretin synthesis is effective in a transgenic mouse model but has not yet been tested in humans. Muscle Nerve, 2007

Ancillary