A variable number of tandem repeat (VNTR) and a dinucleotide repeat polymorphism in IL-4 gene were examined in Swedish myasthenia gravis (MG) patients and ethnically matched healthy individuals. There were no associations between these polymorphisms and MG patients as a whole group or stratified by clinical and pathological parameters and genetic markers in MHC gene (TNF-alpha NcoI allele 2) and IL-l gene (IL-1 beta TaqI allele 2). This lack of association between the IL-4 gene and disease contrasts to our previous results showing that MG is associated with higher secretor phenotypes of two prototype proinflammatory cytokine (TNF-alpha and IL-1) genes. (C) 1998 Elsevier Science B.V. All rights reserved.