00:01
Alport syndrome is also called hereditary nephritis,
and affects approximately 1 in 5,000-10,000 people in the United States.
00:10
It is mostly inherited in an X-linked pattern and consists of a primary basement membrane disorder
arising from mutations in genes encoding various members of the collagen type 4 protein family.
00:23
The signs and symptoms are those of a progressive glomerulonephritis,
combined with sensorineural hearing loss and visual disturbances due to abnormalities affecting the cornea, lens, and retina.
00:37
The initial kidney manifestation is usually an asymptomatic, persistent microscopic hematuria, often with red cell casts.
00:45
Alport syndrome is seen in approximately 3% of children with kidney failure and 0.2% of adults with kidney failure.
00:54
The preferred method is by Next Generation Sequencing, searching for mutations in genes that encode the collagen IV protein (e.g., COL4 gene)
Skin biopsy is also acceptable: Look for absent or mosaic basement membrane protein in X-linked cases,
immunohistochemical staining against the alpha-5 chain of type IV collagen.
01:17
If the diagnosis is not confirmed by NGS or skin biopsy, then a kidney biopsy is performed in suspected cases.
01:24
In the EM photograph, note the splitting of the of the glomerular basement membrane
(and the thickening, fraying, and laminations of the GBM; see arrows)”