The usual age of onset of these two types is 55 to 60 years old. Without treatment, life expectancy is between six months and four years. In the developed world about 1 per 1,000 people die annually from systemic amyloidosis. Amyloidosis has been described since at least 1639. Signs and symptoms
The presentation of amyloidosis is broad and depends on the site of amyloid accumulation. The kidney and heart are the most common organs involved. Kidneys
Amyloid deposition in the kidney often involve the glomerular capillaries and mesangial regions, affecting the organs ability to filter and excrete waste and retain plasma protein. This can lead to high levels of protein in the urine (proteinuria) and nephrotic syndrome. Several types of amyloidosis, including the AL and AA types, are associated with nephrotic syndrome. Approximately 20% and 40-60% of people with AL and AA amyloidosis respectively progress to end-stage kidney disease requiring dialysis. Heart
Amyloid deposition in the heart can cause both diastolic and systolic heart failure. EKG changes may be present, showing low voltage and conduction abnormalities like atrioventricular block or sinus node dysfunction. On echocardiography, the heart shows a restrictive filling pattern, with normal to mildly reduced systolic function. AA amyloidosis usually spares the heart. Cardiac amyloidosis can present with symptoms of heart failure including shortness of breath, fatigue, and edema.
Many amyloidoses are inherited, due to mutations in the precursor protein.Other forms are due to different diseases causing overabundant or abnormal protein production – such as with overproduction of immunoglobulin light chains (termed AL amyloidosis), or with continuous overproduction of acute phase proteins in chronic inflammation (which can lead to AA amyloidosis).About 60 amyloid proteins have been identified so far. Of those, at least 36 have been associated with a human disease.All amyloid fibril proteins start with the letter "A" followed by the protein suffix (and any applicable specification). See below for a list of amyloid fibril proteins which have been found in humans:

Alternative
An older clinical method of classification refers to amyloidoses as systemic or localised:

Systemic amyloidoses affect more than one body organ or system. Examples are AL, AA and Aβ2m. Localised amyloidoses affect only one body organ or tissue type. Examples are Aβ, IAPP, Atrial natriuretic factor (in isolated atrial amyloidosis), and Calcitonin (in medullary carcinoma of the thyroid)Another classification is primary or secondary. Primary amyloidoses arise from a disease with disordered immune cell function, such as multiple myeloma or other immunocyte dyscrasias. Secondary (reactive) amyloidoses occur as a complication of some other chronic inflammatory or tissue-destroying disease. Examples are reactive systemic amyloidosis and secondary cutaneous amyloidosis.Additionally, based on the tissues in which it is deposited, it is divided into mesenchymal (organs derived from mesoderm) or parenchymal (organs derived from ectoderm or endoderm). Treatment
Treatment depends on the type of amyloidosis that is present.