Familial Renal Amyloidosis: FGA Sequencing

Diagnostic Use

Familial renal amyloidosis (FRA) is a distinct form of amyloidosis that is hereditary (autosomal dominant) and predominantly affects the kidneys. Most cases of systemic amyloidosis (with renal involvement) are acquired and caused by deposition of immunoglobulin chains (primary amyloidosis, AL) or serum amyloid protein (secondary amyloidosis, AA). In the remaining cases, the disease is hereditary and of these cases, 80% will be caused by the Glu526Val mutation in exon 5 of the Fibrinogen Aα gene. Less frequently other fibrinogen Aα gene mutations (within exon 5) are involved or mutations in other genes: ApoAl; ApoAll; Lysozyme; and Cystatin C.

FRA typically manifests in mid to late adult life. The age at presentation, like other clinical features varies among mutations and even within individual kindreds. Most patients diagnosed with Fibrinogen Aα Glu526Val present in late to middle-age with proteinuria or hypertension and progress to end-stage renal failure over 5-10 years. Penetrance and clinical features can be highly variable between different families with the same mutation or even within individual kindreds.

Indications: Family history of FRA ± symptoms of renal dysfunction including proteinuria, hypotension, biopsy immunohistochemistry staining of amyloid fibrils positive with antibody against fibrinogen Aα chain or staining negative for SAA, lambda Ig chains and APOAI.

Department

Genetics - Molecular Pathology

Delphic Registration Code

MOLP

Constituent Tests

Synonyms

FRA

Turnaround Time

4 weeks

Test Code

7312