Maternal-fetal alloimmunisation with antenatal glomerulopathies (FMAIG) is a recently described allo-immune disorder that results from the production of maternal antibodies which cross the placenta, bind to fetal glomerular podocytes and thereby cause renal dysfunction. The pathogenic antibodies are directed against CD10/neutral endopeptidase (NEP). The infant's mother is apparently healthy but is genetically NEP-deficient, and thus becomes immunized against CD10/NEP expressed by placental cells during her first pregnancy. This disease, that we have now diagnosed in five families, is the first described organ-specific disorder due to maternal-fetal allo-immunisation. Because future pregnancies in CD10/NEP-immunized mothers are at high risk for the fetus, antigen-driven therapies aimed at eliminating pathogenic antibodies are urgently needed. This will require identification of the pathogenic epitopes born by the antigen.