Amyloid neuropathy is a symptom of amyloidosis, or the deposition of amyloid in tissues, explains Johns Hopkins Medicine. It specifically indicates the damage that amyloid does to peripheral nerves and the resulting outcomes of this dysfunction.
Amyloid refers to any protein fragments the body synthesizes from amyloid precursor protein, which is present throughout the body. Amyloid is a building block of cell membranes and is essential to neural growth and repair, states the Research Collaboratory for Structural Bioinformatics.
The body does not use all the amyloid it produces, and it normally breaks unused protein fragments down, explains the Bright Focus Foundation. Occasionally, these fragments remain in the tissues and organs, where they harden and damage nerves.
In some instances, the body may produce faulty proteins whose fragments do not break down. With transthyretin familial amyloid polyneuropathy, a genetic mutation causes the body to manufacture an abnormal variant of TTR protein, a protein present in cerebrospinal fluid, states WebMD. Consequently, doctors occasionally run genetic tests in the blood if they suspect TTR-FAP, according to Johns Hopkins Medicine.
Similar to neuropathy associated with diabetes or vitamin deficiency, symptoms of amyloid neuropathy may include numbness, difficulty balancing, painful sensations, nausea and diarrhea. Treatment may include chemotherapy, stem-cell transplant or an organ transplant, depending on the type of amyloidosis.