Congenital and infantile nephrotic syndromes are those that manifest during the first year of life. They include diffuse mesangial sclerosis and Finnish-type nephrotic syndrome.
(See also Overview of Nephrotic Syndrome.)
dialysis or kidney transplantation, may be necessary to stop the proteinuria.
Diffuse mesangial sclerosis
This nephrotic syndrome is rare. Inheritance is variable. It is caused by a mutation in the PLCE1 gene, which codes for phospholipase C epsilon. Progression to end-stage kidney disease occurs by age 2 or 3 years.
Patients with severe proteinuria may require bilateral nephrectomy because of severe hypoalbuminemia; dialysis should be initiated early to ameliorate nutritional deficits and mitigate failure to thrive. The disorder usually recurs in a renal graft.
Finnish-type nephrotic syndrome
This syndrome is an autosomal recessive disorder that affects 1/8200 Finnish neonates and is caused by a mutation in the NPHS1 gene, which codes for a podocytic slit-diaphragm protein (nephrin).
Finnish-type nephrotic syndrome is rapidly progressive and usually necessitates dialysis within 1 year. Most patients die within 1 year, but a few have been supported nutritionally until renal failure occurs and then managed with dialysis or transplantation. However, the disorder may recur in a renal graft.
Other congenital nephrotic syndromes
Several other rare congenital nephrotic syndromes are now genetically characterized. These disorders include
Corticosteroid-resistant nephrotic syndrome (defective NPHS2 gene coding for podocin)
Familial focal segmental glomerulosclerosis (defective ACTN 4 gene coding for alpha-actin 4)
Denys-Drash syndrome, which is characterized by diffuse mesangial sclerosis, male pseudohermaphroditism, and Wilms tumor (defective WT1 gene)
