We want to test the hypothesises that patients with nephrotic syndrome have a higher excretion of AQP2 in the urine,that they have a higher concentration of AVP,and a lower C-H2O.Everything will normalize, when the syndrome is in remission.Furthermore we want to test the hypothesis that the expression of mutations in the NPHS2-gene,that codes for podocin,will cause a lack off or a poorer response in the treatment of nephrotic syndrome