Long-Term Clinical Course of COL4A1-Associated Nephropathy and Assessment of α1 Chain of Type IV Collagen Expression in Kidney Biopsy Specimens: A Case Report.
Ryuto Yoshida, Akinori Hashiguchi, Takashin Nakayama et al.
✦ AI-curated · Sources linked
Case in brief
A 39-year-old man with a heterozygous p.G1239R COL4A1 variant presented with persistent microscopic hematuria and a gradual decline in estimated glomerular filtration rate over 10 years. Kidney biopsy revealed focal global glomerulosclerosis and mild tubular dilatation. Immunofluorescence showed reduced α1 chain of type IV collagen expression in the tubular basement membrane, while electron microscopy indicated focal thinning and other abnormalities in the glomerular and tubular basement membranes.
What made this case unusual
The case highlights the use of correlative light and electron microscopy (CLEM) to assess COL4A1 expression, revealing significant insights into the pathology associated with COL4A1 variants.
Diagnostic / clinical pearl
Clinicians should consider COL4A1-associated nephropathy in patients with hematuria and thin glomerular basement membranes, alongside Alport syndrome, for accurate diagnosis and management.
Why it matters
This case underscores the importance of recognizing COL4A1 nephropathy for systemic risk assessment and genetic counseling, particularly in patients with atypical presentations.