Figure 1.

Renal biopsy from patient 3 with a novel FGA mutation. Striking glomerular enlargement and almost complete obliteration of the normal architecture by amyloid deposition is shown when (a) stained with Congo red and viewed using brightfield illumination, (b) stained with Congo red and viewed under crossed polarized light, and (c) immunostained with antibodies to fibrinogen A alpha chain. For comparison, a renal biopsy from a patient with kappa light-chain (AL) amyloidosis is shown; (d), (e) extensive amyloid is visible within glomeruli, (f) but there is no staining above the background of the amyloid deposits with an antibody against fibrinogen A alpha chain.