Isoelectrofocusing in the Study of the Bf System: Existence of Two Common Subtypes of the Bf^F Allele

Abstract

The inherited polymorphism of the properdin factor B (Bf system) was studied by isoelectrofocusing in polyacrylamide gel (PAGIF, pH range 5.0-8.0), followed by immunofixation. Using the described technique, two different subtypes of F bands are visible (designated as F' and F"). Studies of 13 families and 48 mother-child pairs are not in contradiction to the assumption of a codominant inheritance by two alleles (Bf^F' and Bf^F") at a single locus.

A History of Complement Genetics

“…Moreover, the Ba fragments of BF F1 and BF S1 carry the same Ba as BF S, suggesting that the mutations producing BF*F1 and BF*S1 occurred in a BF*S gene [39]. A major addition to the BF polymorphism was the recognition by two groups independently [41,42] of the division by isoelectric focussing of BF*F into BF*FA and BF*FB. The BF FA/FB distinction was shown by Siemens et al [43] to be in the Ba fragment.…”

Factor B Reference Typing Report

“…With all applied methods the reference typing revealed both subtypes (FA and FB) to be identical in the samples of all groups. There were only differences in no-+ menclature: the BF Fb subtype according to 2 Abbai et al [7] was characterized by an anodal position of electrophoretic bands in the three applied subtyping methods and there fore corresponds to the FA subtype accord-type alleles ing to the nomenclature proposed by Geserick et al [5], correspondingly Fa was typed as FB.…”

“…Standard variant determination of relative migration (RM) was done according to the BF Nomenclature Statement [4], BF subtypes were seen in native BF by polyacrylamide gel isoelectric focus ing according to Geserick et al [5,6], by AG-IEF according to Abbai et al [7], and after treatment with 0.5 units neuraminidase type VI (or VII) from Clos tridium perfringens (NANA'se) per 80 pi serum sam ple over 16 h at room temperature [Siemens et al, in preparation], and in the Ba and Bb fragments by AG-IEF as described by Siemens et al [8]. For the RFLP determination with Taq I the method as described by Fathallah et al [9] was applied; for Msp I we used the For the group of common BF subtypes samples were obtained from 5 laboratories with complete family data (ABB, GES, LOK, MAU, ARN).…”

“…The discovery of BF F subtypes by Geserick et al [11] and Teng and Tan [12] was followed by several descriptions of subtypes and variants of the F and S allele through use of different methods and designations. Sev enty-three BF pretyped serum or plasma samples from 11 laboratories were investi gated, most of them by six different methods for their subtype classification.…”

A BF subtype “Fb1” is a marker gene of some mongoloid populations

“…Four sets of subtype have been recognized for each of the two common alleles, BF*F and BF*S, as follows: FA(=F', Fb) and FB(-----F", Fa) (Teng and Tan, 1982;Geserick et al, 1983;Abbal et al, 1985;Nagai et al, 1986;Segurado and Arnaiz-Villena, 1989), SA and SB (David et al, 1983), Sb (Weidinger et al, 1984), and Fbl (Nakamura et al, 1987;Suzuki et al, 1987a, b;FB in Nishimukai et al, 1988). It is reported that the SA-SB subtype set may be misinterpretation resulting from ambiguous banding patterns due to spontaneous BF conversion during sample collection and/or sample storage (Segurado and Arnaiz-Villena, 1989).…”