familial amyloidosis

amyloidosis /am·y·loi·do·sis/ (am″ĭ-loi-do´sis) a group of conditions characterized by the accumulation of insoluble fibrillar proteins (amyloid) in various organs and tissues such that vital function is compromised. The associated disease states may be inflammatory, hereditary, or neoplastic, and deposition can be local, generalized, or systemic. The most widely used classification is based on the chemistry of the amyloid fibrils and includes primary (AL), secondary (AA), and familial forms.

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AA amyloidosis  secondary a.

AL amyloidosis  primary a.

ATTR amyloidosis  the most common form of familial amyloidosis (q.v.), associated with mutations of the gene encoding transthyretin.

familial amyloidosis  any inherited form of amyloidosis; usually used to denote any of various systemic autosomal dominant disorders of amyloid deposition that involve the nervous system. The most common form, ATTR amyloidosis, is associated with mutations of the transthyretin protein, but rare mutations of other proteins can also be a cause. The term can also, less commonly, be said to include several types of secondary amyloidosis in which the deposition is associated with an inherited disease (e.g., familial Mediterranean fever). Subclassifications are based on clinical presentation and biochemical composition of the fibrils deposited; originally they were distinguished on the basis of kinship. See also familial amyloid polyneuropathy, under polyneuropathy.

hemodialysis-associated amyloidosis  that occurring in patients on long-term hemodialysis, caused by the deposition of beta2-microglobulin, which cannot be removed from the blood by hemodialysis, in the joints, synovial membranes, and tendon sheaths. Manifestations include carpal tunnel syndrome and arthritis.

hereditary amyloidosis  familial a.

primary amyloidosis  a systemic form in which the deposited fibrillar material is AL amyloid; it may be due to either aberrant synthesis or processing of immunoglobulin light chains. It is associated with tumors or dyscrasias of immunoglobulin-producing plasma cells and involves some combination of the skin and subcutaneous tissue, nerves, liver, spleen, heart, kidney, intestine, and tongue. Called also AL a..

reactive systemic amyloidosis  secondary a.

renal amyloidosis  amyloid deposits in the kidneys; in the primary type the fibrils are mainly AL amyloid, and in secondary types they are AA amyloid. Secondary types may accompany inflammatory disorders, chronic infectious diseases, or neoplastic diseases.

secondary amyloidosis  that in which AA amyloid is deposited, and which occurs secondary to a chronic inflammatory condition, either infectious or noninfectious. It usually involves the liver, spleen, and kidneys.

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familial amyloidosis

n.

A hereditary form of amyloidosis associated with familial Mediterranean fever, cold hypersensitivity, various patterns of neuropathy, or amyloid deposits in various organs.