Polymorphic variants of B2 receptors for bradykinin (B2BKR) have been postulated to influence a clinical manifestation of hereditary angioedema. In this study, exon 1 nonanucleotide deletion polymorphism in the B2BKR gene was examined in 37 patients with hereditary angioedema. The patients were grouped according to disease severity or the age of the first clinical manifestation of disease. No significant differences in allelic frequencies were found between particular subgroups of patients. Therefore, we concluded that this polymorphism does not seem to have any significant effect on the course and severity of hereditary angioedema in Caucasians.