Congenital nephrosis was the first monogenic entity found to be enriched in the Finnish population. This nephrotic syndrome of newborns is due to a deficiency of nephrine, a transmembrane podocyte adhesion molecule at the glomerular slit diaphragm. The disease is detected soon after delivery of a baby with a large placenta. Proteinuria, ascites, edema, and hypoproteinemia are the main findings; causing to failure to thrive and susceptibility to infections. The nephrotic manifestations are resistant to conventional drug therapy and without renal transplantation the patients succumb during the first two years of life.