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Currently filtering by tag: COL4A4

Diagnose This (August 31 ,2020)

Alport Syndrome, COL4A5, COL4A3, COL4A4, Alport, X-linked, Hearing loss, GBM multilamellation
Q: What is your diagnosis based on this IF staining pattern in a patient with hematuria and proteinuria?   The immunofluorescence image is that of an Alport panel. The red staining highlights the alpha 2 subunit of collagen type IV while the green staining is that of the alpha 5 subunit of collagen type IV. The image shows segmental loss of the alpha 5 staining of type IV collagen along the glomerular basement membranes compatible with Alport syndrome. Alport syndrome is an inherited disease secondary to mutations in the alpha 3, 4, and 5 subunits of type IV collagen. The...

Alport Syndrome

This biopsy from a 22-year-old Hispanic male with a history of hematuria, subnephrotic proteinuria, and chronic kidney disease shows essentially unremarkable glomeruli (Fig 1) with moderate interstitial fibrosis and tubular atrophy, and frequent interstitial foam cells (Fig 2).  Furthermore, electron microscopy shows irregular glomerular basement membranes (GBM) that vary between thick and thin, along with segmental lamellation and diffuse epithelial foot process effacement (Fig 3).  These findings, along with the clinical history are consistent with Alport syndrome. Alport syndrome is a spectrum of diseases affecting the synthesis of type IV collagen, which is the main component of the glomerular basement...

Alport Skin

The most common form of Alport syndrome shows an X-linked dominant inheritance pattern and is caused by mutations in the COL4A5 gene located in the Xq22 region that encodes for the alpha5 chain of type IV collagen. The glomerular basement membrane consists of alpha1, alpha2, alpha3, alpha4 and alpha5 chains, whereas no alpha6 chains are present.  Within the glomerular basement membranes, the alpha3, alpha4, and alpha5 form a network of collagen. Abnormalities, even in one of the chains, can alter this network formation. However, there will be persistence of the alpha1 and alpha2 chains. As a result, diagnosis of Alport is...

Thin GBM Disease

This 41-year-old female presents with microscopy hematuria and subnephrotic proteinuria. The clinical workup is negative for urinary tract infection, nephrolithiasis or other lower urinary tract diseases. A renal biopsy shows essentially unremarkable glomeruli by light microscopy (Fig 1), with scattered red blood cells within the tubular lumens and marked, uniform thinning of the glomerular basement membranes by electron microscopy (Fig 2). These findings are consistent with thin basement membrane disease (TBMD). TBMD affects approximately 1 to 5% of the general population. Mutations in the COL4A3 and COL4A4 genes are identified in up to 40% of affected patients.  Furthermore, TBMD may...