[Demonstration of a "new" BF-variant (BF S Berlin) using isoelectric focusing].

Using the islelectrofucising in polyacrylamide gel for BF typing in the population from Berlin (GDR) a "new" variant was found. This variant is situated cathodically of the BF S line, but it is not detectable by means of agarose gel electrophoresis. Therefore the common BF nomenclature is not applicable. The designation "S Berlin" is proposed. Typing the family of the proposita the same phenotype (S Svar .) was found in the serum of her daughter. This result confirms a codominant inheritance of the new allele. The observed allele frequency is 0.0017.