The FOrMe Registry (The German Focal Segmental Glomerulosclerosis and Minimal Change Disease Registry)

Idiopathic Nephrotic Syndrome is characterized by proteinuria, volume retention, hyperlipidemia, hypoalbuminemia. As Minimal Change Disease (MCD) represents by far the most prevalent underlying diagnosis in children older than 1 year, a kidney biopsy is usually deferred in these cases. In adolescence and adults, a kidney biopsy is crucial for the diagnosis because MCD and FSGS account for only 10-15 and 12-35 percent of all cases of nephrotic syndrome respectively. Pathomechanisms as well as optimal treatment remain elusive as systematic trials are scarce and hampered by low incidence and heterogenicity of the clinical presentation. To bridge this informational gap, the investigators identified the need for a German registry of pediatric and adult patients with idiopathic nephrotic syndrome (in children) and biopsy-proven MCD/FSGS (in adults). The registry will record clinical data of participants regarding basic demographics, initial presentation, hereditary traits, disease course and treatment modalities as well as quality of life, concomitant diseases, and comedication. During the initial visit and to a lesser intent on follow-up visits, biomaterials (blood, urine, DNA, feces, tissue) will be collected and stored in a state-of-the art biobank. This material will be available to collaborators to support research on idiopathic nephrotic syndrome and MCD/FSGS. By the time of completion, the registry will provide data on clinical courses and outcome of approximately 500 patients that can easily be correlated with biomaterials giving insight into risk factors, prognostic parameters, and association with comorbidities. Tissue sections of all patients that undergo kidney biopsy (all adult and some pediatric patients) will be digitalized, annotated, and analyzed by a panel of nephropathologists. Histopathologic features will be individually assessed and scored according to a set of descriptors that was developed and is used by the American NEPTUNE (Nephrotic Syndrome Study Network).