Major primary glomerular diseases in children and adolescents are nephrotic syndrome and IgA nephropathy. Genetic background of nephrotic syndrome has been extensively investigated in recent decade. Several mutations related to glomerular microstructure defects have been identified. This allowed to diagnose the mechanism of first year of life related diseases and also to explain resistance the therapy seen in some older patients. In selected cases these investigations allowed to identify the patients, who gained clinical benefit from pharmacotherapy, nevertheless the genetic background of the disease. Alternative therapy was introduced in specific cases, based on monoclonal antibody – rituximab. The new pathological scoring system of disease severity and outcome, named Oxford cassification, was introduced in cases of IgA nephropathy