Homozygosity for the E526V Mutation in Fibrinogen A Alpha-Chain Amyloidosis: The First Report

Figure 1

Homozygous E526V (p.Glu545Val) mutation in the fibrinogen alpha-chain gene (FGA) associated with fibrinogen A alpha-chain amyloidosis in a Portuguese patient. (a) shows abundant glomerular amyloid deposition with typical apple-green birefringence (Congo red staining under polarized light, ×200, left). Immunohistochemical staining was positive with polyclonal anti-fibrinogen antibodies, (×200, right). (b) shows a partial sequence chromatogram of FGA. The mutation identified in the proband, which alters codon 545 (position 526 of the mature protein) from GAG (glutamic acid) to GTG (valine), is depicted in a circle. (c) shows the pedigree of the affected kindred. The homozygous patient (proband) is indicated by the arrow. The FGA p.Glu545Val mutation was identified heterozygously in family members III7, III8, III10, IV3, IV4, IV5, and IV6 (indicated by half-solid symbols). Obligatory heterozygotes IV2 and IV7 (indicated by question marks) did not perform genotyping because the former was abroad and the latter died at young age. Those with chronic renal failure who have not undergone histologic or genetic testing are indicated by a black column inside the symbol. Familiars whose genetic tests were negative are indicated by an N inside the symbol. Blank symbols indicate that tests have not been conducted and/or information is unavailable for these individuals. Slashes denote deceased members.

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