Types of amyloidosis
Other types
AL, AA and ATTR are the most commonly recognised systemic forms of amyloidosis. Other forms include rare hereditary amyloidoses and localised amyloidosis. Two situations sit outside that description: inherited proteins other than transthyretin, and deposits that never leave the organ in which they formed. They have little in common — except that both are exceptions, and both hinge on a precise diagnosis.
01
The exceptions
Key idea
Both are rare, and neither can be recognised from the symptoms alone. In both, naming exactly what has been deposited — and where — is what makes treatment possible.
Beyond the common forms
AL, AA and TTR account for the great majority of amyloidoses, and each has its own page. What remains are forms so uncommon that most doctors will not see one.
That rarity is itself the difficulty. Neither of the two described here announces itself; both are usually found while looking for something else entirely.
Why they are grouped here
Not because they resemble one another — they do not. One is inherited and attacks the kidneys; the other is acquired and stays in a single organ.
They are grouped because each falls outside the ordinary description of an amyloidosis, and because in both cases the laboratory, not the bedside, has the last word.
02
Two exceptions
One is a question of which protein. The other is a question of how far it travels.
RARE HEREDITARY
Inherited proteins other than TTR
Mutations in the fibrinogen alpha chain, the apolipoproteins, lysozyme or gelsolin. All are transmitted in an autosomal dominant way, and the kidneys are the principal target.
The symptoms can be identical from one to the next while the treatments have nothing in common.
LOCALISED
Deposits confined to one organ
Usually AL amyloid — the same light chains as in the systemic disease — but produced by plasma cells sitting inside the organ itself. Nothing enters the bloodstream, so nothing is deposited elsewhere.
The airways and the bladder are the commonest sites, and the treatment is local.
In both, the biopsy is often taken to rule out something else, and the amyloid is found by surprise. What follows — typing the protein, establishing how far it has spread — is what decides the treatment.
This page is intended as general information for patients, families and healthcare professionals. It does not replace medical advice. Always discuss your situation with your own specialist team.