Minimal change nephropathy (MCN) is an important cause of nephrotic syndrome, especially in children, that is strongly associated with atopy and IgE production. The immunogenetics of MCN are poorly understood. Interleukin-4 (IL-4) is the critical cytokine involved in the development of atopy. Polymorphic regions in the genes encoding IL-4 itself and the IL-4 receptor have been demonstrated that may predispose to increased activity. We have analysed these polymorphisms in 149 patients with MCN and 73 controls to test the hypothesis that these loci are involved in genetic predisposition to MCN. In our populations there were no polymorphisms in the IL-4 promoter. We did confirm allelic variation in a dinucleotide repeat in the second intron of the IL-4 gene, but there was no significant difference between allele distributions in MCN and controls. Similarly, allele frequencies for the IL-4 receptor alpha chain polymorphism were similar in patients and controls. Genetic loci which are believed to influence IL-4 responsiveness and to predispose to atopy do not appear to be associated with susceptibility to MCN.