Fibronectin glomerulopathy: an unusual cause of adult-onset nephrotic syndrome.
We report the case of a 50-year-old woman with nephrotic-range proteinuria and lobular glomerulopathy on kidney biopsy. Homogenous glomerular deposits were non-immune reactive, but immunofluorescence microscopy for fibronectin was strongly positive. Ultrastructurally, the deposits were granular with focal fibril formation, leading to a diagnosis of fibronectin glomerulopathy. Mutational analysis revealed a heterozygous missense mutation in fibronectin (leading to the tyrosine at amino acid 973 being replaced by cysteine [Y973C]), confirming the diagnosis. This mutation affects Hep-III, one of the heparin-binding domains of fibronectin, and results in functional abnormalities.
Department of Pathology, Stanford University, Stanford, CA 94305, USA.
Mridula
M
Nadamuni
Rossella
R
Piras
Sami
S
Mazbar
John P
JP
Higgins
Neeraja
N
Kambham
D017668:Age of Onset; D005260:Female; D015432:Glomerulonephritis, Membranoproliferative / Q000150:complications*; D006801:Humans; D008875:Middle Aged; D009404:Nephrotic Syndrome / Q000209:etiology*