Details
67-year old male with microscopic haematuria not yet diagnosed. Otherwise healthy, but with strong family history of renal failure.
Alport syndrome is a hereditary disorder of type IV collagen, with about 85% of the cases being X-linked, with mutations in COL4A5. The collagen abnormalities result in hematuria with chronic renal failure, accompanied by abnormal formation of structures in the eye (lens, cochlea), and deafness.
These electron microscopic (EM) pictures show abnormalities in the glomerular basement membrane (GBM) that are characteristic of Alport disease. These include thick and split GBM, but the GBM can be thin, as in this case. In fact, thin basement membrane disease (TBMD) would have been in the differential diagnosis, and TBMD is another relatively common cause of asymptomatic haematuria. Other notable features include multi-lamellation of GBM lamina densa (resulting in “basket-weave” appearance) and podocyte foot process effacement.
Light microscopy (not shown) features are generally not as helpful. Mild wrinkling of the GBM was seen, with some peri-glomerular fibrosis. Tubular atrophy and interstitial fibrosis can be seen in late course of Alport disease in more prominent cases. Focal segmental glomerulosclerosis can result in more severe cases.
Details
67-year old male with microscopic haematuria not yet diagnosed. Otherwise healthy, but with strong family history of renal failure.
Alport syndrome is a hereditary disorder of type IV collagen, with about 85% of the cases being X-linked, with mutations in COL4A5. The collagen abnormalities result in hematuria with chronic renal failure, accompanied by abnormal formation of structures in the eye (lens, cochlea), and deafness.
These electron microscopic (EM) pictures show abnormalities in the glomerular basement membrane (GBM) that are characteristic of Alport disease. These include thick and split GBM, but the GBM can be thin, as in this case. In fact, thin basement membrane disease (TBMD) would have been in the differential diagnosis, and TBMD is another relatively common cause of asymptomatic haematuria. Other notable features include multi-lamellation of GBM lamina densa (resulting in “basket-weave” appearance) and podocyte foot process effacement.
Light microscopy (not shown) features are generally not as helpful. Mild wrinkling of the GBM was seen, with some peri-glomerular fibrosis. Tubular atrophy and interstitial fibrosis can be seen in late course of Alport disease in more prominent cases. Focal segmental glomerulosclerosis can result in more severe cases.