Human BF*F-subtypes: segregation analysis with inclusion of MHC haplotypes

Geserick, G.; Mauff, G.; Siemens, I.; Waltz, H.; Mayer, Antonia; Bender, Klaus; Rose, M; Goldmann, S. F.; Brenden, Martina; Schröder, Helga

doi:10.1007/bf00285166

Cited by 2 publications

(2 citation statements)

References 27 publications

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“…At present, the reliable distinction of all BF F subtype phenotypes is only possible with AGIEF methods [34,37]. This highlights the special advantages of agarose as the gel medium in demonstrating this polymorphism.…”

Section: Comparison Of Ief Methodsmentioning

confidence: 85%

Improvement of BF typing and of BF F subtyping after neuraminidase treatment in the unconverted and converted factor B

et al. 1992

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When neuraminidase-treated sera are analyzed by agarose gel isoelectric focusing, the factor B (BF) banding pattern is reduced to predominantly one major band without cathodically positioned bands. This not only makes unequivocal typing of BF allotypes possible but also the reliable distinction of all BF F subtype phenotypes with delimitation of "BF F subtype variants". With this new method, serum aging affects the BF determination to a lesser extent than when applying methods that separate native sera. We show that sialylation is not responsible for the BF F subtype polymorphism. All of the investigated BF allotype bands, including those characteristic of the subtypes, show functional hemolytic activity. The banding pattern after removal of neuraminic acid residues ranges from pH 6.8 to 7.3 for factor B, from pH 5.3 to 5.9 for the Ba fragment, and from pH 8.2 to 8.7 for the Bb fragment. The protein structure of factor B is also discussed. Eliminating the superimposition of bands in different BF allotypes, as demonstrated by these methods, proved to be necessary for the detection of hypomorphic BF gene products (BF QL), which are expressed by assumed BF*Q0 alleles in heterozygous genotypes. This allows investigation of BF*Q0 alleles on a protein level, which complements molecular genetic approaches.

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Section: Comparison Of Ief Methodsmentioning

confidence: 85%

Improvement of BF typing and of BF F subtyping after neuraminidase treatment in the unconverted and converted factor B

et al. 1992

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“…The two subtypes of BF F show different association patterns with HLA markers. BF FB seemed to be linked to HLA-B35 while BF FA showed a strong linkage with all the alleles of the following haplotype: HLA-A29, Cw-, B44, C4A3B I , DR7; (Abbal et al, 1985;Geserick et al, 1989;Thomas & Darke, 1992). The use of DNA techniques as illustrated here would allow BF polymorphism to be applied to further genetic analysis.…”

Section: Discussionmentioning

confidence: 99%

Genomic Analysis of the F Subtypes of Human Complement Factor B

Jahn¹,

Mejéa²,

Thomas

et al. 1994

Int J Immunogenetics

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Factor B of human complement is encoded within the Major Histocompatibility Complex (MHC) and is polymorphic, with up to 30 alleles defined by electrophoretic mobility. One of the most common alleles, BF*F, is subdivided into the FA and FB subtypes, which differ at the gene level by non-synonymous base substitutions in the seventh codon. We have found at this position a new restriction site polymorphism, as a Bsl I site absent from the FB allele. Using this restriction polymorphism, we have developed a method for BF F subtype determination, based on amplification by polymerase chain reaction of the 5' end of the BF gene, and digestion with Bsl I. This new method has been applied to a panel of 29 selected BF F individuals. A single strand DNA conformation analysis of the same region of the gene allowed us to confirm the above DNA-based BF F subtyping. During this study, two BF*F1 alleles showed discrepancies between protein and DNA typing, which were confirmed by our sequencing data. These were identical, in the 5' region, to BF*S and BF*FB genes, respectively. In a comparison with two protein subtyping methods, identical results were found for only one third of the selected samples. The conflicting results may arise, in part, from previously undescribed molecular heterogeneity within BF F subtypes, or from the presence of a null allele. Our new method allows BF*F subtyping to be used with confidence in the definition of disease-associated MHC haplotypes.

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Human BF*F-subtypes: segregation analysis with inclusion of MHC haplotypes

Cited by 2 publications

References 27 publications

Improvement of BF typing and of BF F subtyping after neuraminidase treatment in the unconverted and converted factor B

Improvement of BF typing and of BF F subtyping after neuraminidase treatment in the unconverted and converted factor B

Genomic Analysis of the F Subtypes of Human Complement Factor B

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