Three siblings with steroid-resistant nephrotic syndrome: new NPHS2 mutations in a Turkish family.

Steroid-resistant nephrotic syndromes often are resistant to additional immunosuppressive agents and tend to progress to end-stage renal disease. Genetic studies in children with familial nephrotic syndrome have identified mutations in genes that encode important podocyte proteins. NPHS2 mutations are responsible for autosomal recessive familial focal segmental glomerulosclerosis (FSGS), and these mutations were detected in both familial and sporadic forms of FSGS. Interethnic differences were suggested to play a role in the incidence of these mutations. In this report, the cases of 3 siblings with steroid-resistant nephrotic syndrome who carry NPHS2 mutations (R238S and P118L) are presented.