December 2, 2019
Diagnose This (December 2, 2019)
- Published: December 2, 2019
- By: L. Nich Cossey, MD
What is your diagnosis?
The photomicrograph shows a high power electron microscopy image of a peripheral capillary loop with irregular subendothelial and subepithelial aspects of the glomerular basement membrane. Additionally, within the glomerular basement membrane, vague splitting can be identified. These findings typically seen in the setting of Alport syndrome, however, they are not definitive (resolving immune complex-mediated glomerulonephritis can show similar findings).
In this case, additional immunofluorescence staining for the alpha 5 subunit of collage Type IV was performed and showed global loss of staining confirming the diagnosis. It is important to note that genetic testing is the definitive testing modality in Alport syndrome and hundreds of mutations have been reported in many different inheritance patterns, not just the traditional X-linked. Because of this a renal biopsy is often very specific but can be relatively insensitive in detecting this disease, especially in female patients and those with familial inheritance patterns of renal disease other than X-linked.