C4 Nomenclature Statement (1990)

Abstract

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.

Allotypes of the fourth component of complement in Korean

“…The results were confirmed by improved electrophoresis after desialisation of plasma (O'Neill et al, 1978;Awdeh and Alper, 1980). So far, at least 13 alleles of C4A and 16 alleles of C4B including a null allele at each locus have been identified among various populations (Mauff et al, 1990). C4A and C4B genes have been found to be duplicated and to be transmitted to offspring in several different haplotypes (Raum et al, 1984;Giles et al, 1987).…”

Associação do alótipo raro C4A6 do sistema complemento com a doença cardíaca reumática

“…A tipagem de C4A e C4B foi determinada em plasma com EDTA, tratado com neuraminidase e carboxipeptidase B (Sigma, St Louis, MO, USA). Após eletroforese de alta voltagem (HVAGE), os alótipos de C4A e C4B foram determinados por imunofixação com anti-C4 humano (Atlantic Antibodies) e teste hemolítico (17) . Para a definição de alguns alelos, foram empregados eletroforese prolongada em gel e Western blot, usando anticorpos monoclonais específicos contra alelos de C4A e C4B (17,18) .…”

“…Após eletroforese de alta voltagem (HVAGE), os alótipos de C4A e C4B foram determinados por imunofixação com anti-C4 humano (Atlantic Antibodies) e teste hemolítico (17) . Para a definição de alguns alelos, foram empregados eletroforese prolongada em gel e Western blot, usando anticorpos monoclonais específicos contra alelos de C4A e C4B (17,18) . A estimativa de alelos não expressos de C4A e C4B foi feita por avaliação semiquantitativa das placas de eletroforese e pelo método MASC (qui-quadrado mínimo) (19,20) .…”

Molecular Genetics of the Human MHC Complement Gene Cluster

“…C4 is complex both at the protein and the genomic levels (table 3). There are two isotypes of C4, C4A (acidic) and C4B (basic) with more than 34 allotypes altogether [19][20][21]. The C4A and C4B proteins are markedly different in electrophoretic mobilities, hemolytic activities, and chemical reactivities [22][23][24].…”