Renal Bx - congenital NS of the Finnish type

Renal biopsy from an infant with congenital nephrotic syndrome (NS) of the Finnish type due to mutations in the NPHS1 gene that encodes nephrin, a transmembrane protein located at the slit diaphragm of the glomerular podocytes. Histologic changes include the characteristic findings of mild mesangial hypercellularity and increased mesangial matrix in the glomeruli, and irregular microcystic dilatation of proximal tubules.