Complotyping and Subtyping of MHC Class I Gene Products in Haplotype Determination for Bone Marrow Transplantation

Brenden²,

Braun-Stilwell³

et al. 1990

Human C4 is most polymorphic at the protein level, distinction between allotypes of the C4A and C4B proteins resting on electrophoretic migration patterns and difference in hemolytic activity. The aim of the C4 reference typing has been the definition of reference variants, the assignment of rare variants, and the investigation of duplicated, deleted, or non-expressed and hybrid genes. Samples from 136 individuals, predominantly with known segregation, from 16 laboratories were investigated by standard electrophoretic techniques, for their relative hemolytic activity, reactivity with monoclonal antibodies and Rg/Ch reagents, a-, and ß-chain types, relative electrophoretic migration distance, as well as the C4/21-OH-TaqI RFLPs. The results were evaluated in three groups; they consisted in the definition of the eight most common C4 alleles, and the ten Rg/Ch standard phenotypes in group I. In group II twelve C4A and fourteen C4B duplications among 96 complotypes, as well as eighteen deleted/non-expressed C4A and twenty-two C4B alleles, and hybrid alleles were seen by correlation of lytic activity, electrophoretic mobility, and monoclonal and/or Rg/Ch reactivity. Group III consisted of the newly defined allotypes A 8, A 7, A 58, A 55, A 45, B 45, B 35, and B 22, furthermore of alleles subdividing the A 1/A 91, and the B 13/ B 12/B 11 regions. The reference typing has allowed reclassification of the majority of described C4 allotypes and resulted in a revision of the C4 nomenclature.

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

C4 Reference Typing Report

Brenden²,

Braun-Stilwell³

et al. 1990

“…ment, with the exception that before neur aminidase (NANA'se), treatment with CARB-B [ 19] should be used if the number of expressed alleles and the relative migra tion distance are to be determined. Additional techniques may be necessary or helpful to define or subtype allotypes and haplotypes, such as Western blots with poly clonal or monoclonal antibodies after pro longed agarose-gel electrophoresis, Rodgers/ Chido typing, C4 a-and ß-chain typing [9,[20][21][22], or DNA TaqI RFLP for the recogni tion of gene size and duplications [6].…”

Section: General Rules For C4 Nomenclature and Technology Of C4 Typingmentioning

confidence: 99%

C4 Nomenclature Statement (1990)

Ca²,

Dawkins³

et al. 1990

A common and revised nomenclature of the allotypes of the fourth component (C4) of human complement has been proposed. It is based on the results of the C4 Reference Typing of the Vlth Complement Genetics Workshop and Conference, Mainz, FRG, 1989, the previous C4 nomenclature and the guidelines for human gene nomenclature (ISGN). The designation of allotypes derives from their relative electrophoretic mobility, the distinction between C4A and C4B proteins from their relative hemolytic activity. Common alleles retain their single digit numeric designation, intermediate variants their two- or three-digit designations; newly discovered alleles should not interfere with already described variants. At least 13 C4A alleles, 16 C4B alleles as well as non-expressed genes at each C4 locus are presently known. There are also duplicated loci of each C4 gene; they should be designated by repetition of the locus symbol at the haplotype or genotype level. As a phenotype they will be placed in parenthesis without repetition of the locus symbol. Aberrant allotypes or hybrid genes should be explained by a special suffix. No special nomenclature is recommended for restriction fragment length polymorphisms. Their designation should follow the general rules of the ISGN.

“…phoresis (Pr-AGE) (LKB Multiphor II) on GelBond membranes for 4 h and subsequent immunofixation with polyclonal anti-C4 (Atlantic Antibodies and Behringwerke) were essentially applied as described [2,12] (see also fig. 1).…”

Section: Introductionmentioning

confidence: 99%

Relative Electrophoretic Migration Distances for the Classification of C4 Allotypes

Brenden²,

Braun-Stilwell³

1990

For the definition of common C4 allotypes relative electrophoretic migration (RM) values were determined. A set of standard C4 variants were investigated by prolonged agarose gel electrophoresis and subsequent immunofixation with specific antiserum. RM distances were measured by laser densitometry. Using an arbitrary standard of 100 units for the migration distance between the C4B 1 and C4A 3 bands a total deviation of ± 6.45% in more than 108 single determinations was found. The common C4 alleles used for standardization were C4A*6, C4A*4, C4A*3, C4A*2, C4B*5, C4B*3, C4B*2, C4B*1. In addition, side by side comparison and admixture of known variants will be necessary for the differentiation of some of the closely migrating allotypes. RM values are now available for eight alleles frequently found in all populations for future comparison and designation of newly discovered C4 allotypes.