Familial amyloid polyneuropathy (FAP) is phenotypically and genetically heterogeneous and is caused by mutations in the genes for transthyretin (TTR), apolipoprotein A1, or gelsolin. The majority of patients with FAP have mutations in the TTR gene. Amyloid deposition may be evident in abdominal fat pad, rectal, or nerve biopsies. The clinical features, histopathology, and EDx reveal abnormalities consistent with a generalized or multifocal, predominantly axonal but occasionally demyelinating, sensorimotor polyneuropathy. Must know: Familial Mediterranean fever (FMF) is the prototype of a group of inherited diseases that are characterized by recurrent episodes of fever with serosal, synol, or cutaneous inflammation and, in some individuals, the eventual development of systemic AA amyloidosis. The innate immune system, with its myeloid effector cells and germline receptors for pathogen-associated molecular patterns and endogenous danger signals, plays a predominant role in the pathogenesis of the autoinflammatory diseases Beta 2-m Amyloidosis is a frequent complication of long-term dialysis (hemodialysis or peritoneal dialysis). In fact, Beta 2-m amyloidosis is a major cause of skeletal morbidity in dialysis-dependent patients. Prions are infectious proteins that cause degeneration of the central nervous system (CNS). Prion diseases are disorders of protein conformation, the most common of which in humans is called Creutzfeldt-Jakob disease (CJD). CJD typically presents with dementia and myoclonus, is relentlessly progressive, and generally causes death within a year of onset. Misfolded prion protein (PrPSc) is associated with amyloidosis. Ref: Mueller P.S. (2007). Chapter 56. Amyloidosis. In J.B. Imboden, D.B. Hellmann, J.H. Stone (Eds), CURRENT Rheumatology Diagnosis & Treatment, 2e; Mueller P.S. (2007). Chapter 56. Amyloidosis. In J.B. Imboden, D.B. Hellmann, J.H. Stone (Eds), CURRENT Rheumatology Diagnosis & Treatment, 2e.