The fetal differentiation and glomerulogenesis is strictly regulated process and many genes are involved in this regulation (1, 2). There is increasing evidence for genetic background of several clinical types of nephrotic syndrome, presented by pediatric, adolescent and adult patients. The major distinctive pattern between specific subgroups of nephrotic syndrome is “syndromic” vs “isolated” type. In “syndromic” pattern renal disease is combined with several extrarenal symptoms, including different types of congenital malformations or malfunctions, present e.g. in Denys-Drash, Frasier’s and nail- patella syndromes or Schimke’s immunoosseous dystrophy. So-called syndromic nephrosis is mainly presented by infants with other co-morbidities, however it should be stressed, that it may be diagnosed also in adolescent or adult patients, as it is in Charcot-Marie-Tooth disease, where there is a link between INF2 gene mutation, formin protein, podocytes and Schwann-cell function (the last causing severe neuropathy) (3). There are no extrarenal symptoms in isolated forms of genetic nephrotic syndrome and clinical symptoms are mainly related to severity of proteinuria.

In some cases there is an evidence for link between type of specific gene mutation and severity of relevant nephrotic syndrome. In congenital nephrotic syndrome of Finnish type, so called Fin-major mutation of NPHS1 causes limitation of number of aminoacids in nephrin molecule from 1241 to 90, while in Fin-minor mutation reduces this number from 1241 to 1108. The clinical expression of those two types is significantly different and in Fin-major related cases the child is delivered being critically ill, with huge general oedema, severe dysproteinemia and renal injury. Those patients do not respond to any antiproteinuric treatment and after short time of vigorous supplementation of protein and albumin – bound vital substances, most of the patients must finally undergo bilateral nephrectomy, to avoid life-threatening complications of massive, untreatable urinary loss of protein. Then the patients are dialyzed until successful renal transplantation, which however may be complicated by “recurrence” of the disease due to anti-nephrin antibodies. Patient with Fin-minor mutation present much more mild clinical course and some of them respond to antiproteinuric treatment with ACEi (captopril) and/or indomethacine. Effect of these drugs is limited to lower proteinuria, while on treatment (4, 5).