Summary
Genetic polymorphism of the second component of human complement (C2) was investigated in 521 unrelated healthy adult Japanese using isoelectric focusing in polyacrylamide gel followed by a specific hemolytic overlay method. Besides the phenotypes reported previously (C, AC and BC), a relatively infrequent double-banded phenotype (tentatively named A'C) was observed. Moreover, a homozygous variant (A) and a heterozygous “double” variant (AB) were observed. The estimated frequencies for the common allele. C2 2(=C2 1), and the variant alleles, C2 A, C2 B(=C2 2) and C2 A′were 0.939, 0.034, 0.022, and 0.006, respectively.
The results of further typing for HLA-A,-B,-C specificities indicated the presence of significant associations of C2 A with HLA-B15 and with A26, and of C2 B with HLA-Bw61. These findings support our previous observation that in Japanese there are allelic combinations showing linkage disequilibrium between C2 and HLA loci which are different from those in Caucasians, and that the C2 structural locus is more closely linked to HLA-B than to HLA-A.
C2 hemolytic activities of each phenotypes were assayed. The mean activity of type AC sera was significantly higher than that of type C or type BC, while there were no differences in the activities among the types C, BC or A'C.
Also presented are two pedigrees demonstrating the segregation of C2 with HLA alleles in which a homozygous C2A or C2B individual was observed.
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References
Alper CA (1976) Inherited sutructural polymorphism in human C2: Evidence for genetic linkage between C2 and Bf. J Exp Med 144: 1111–1115
Borsos T, Rapp HJ, Mayer MM (1961) Studies on the second component of complement I. The reaction between EAC'1,4 and C'2: Evidence on the single site mechanism of immune hemolysis and determination of C'2 on a molecular basis. J Immunol 87:310–325
Dewald G, Rittner C (1979) Polymorphism of the second component of human complement (C2). Vox Sang 37:47–54
Gorman JC, Jackson R, Desantola JR, Schreffler D, Atkinson JP (1980) Development of a hemolytic assay for mouse C2 and determination of its genetic control. J Immunol 125:344–351
Hobart MJ, Lachmann PJ (1976) Allotypes of complement components in man. Transplant Rev 32:26–42
Meo T, Atkinson J, Bernoco M, Bernoco D, Ceppellini R (1976) Mapping of the HLA locus controlling C2 structural variants and linkage disequilibrium between alleles C22 and Bw115. Eur J Immunol 6:916–919
Meo T, Atkinson JP, Bernoco M, Bernoco D, Ceppellini R (1977) Structural heterogeneity of C2 complement protein and its genetic variats in man: A new polymorphism of the HLA region. Proc Natl Acad Sci USA 74:1672–1675
Nagaki K, Iida K, Inai S (1974) A new method for the preparation of EAC14 cell with human or guinea-pig serum. J Immunol Method 5:307–317
Olaisen B, Teisberg P, Gedde-Dahl T Jr, Thorsby E (1978) Genetic polymorphism of the second component of human complement (C2). Hum Genet 42:301–305
Pariser KM, Raum D, Berkman EM, Alper CA, Agnello V (1978) Evidence for a silent or null gene in hereditary C2 deficiency. J Immunol 121:2580–2581
Raum D, Glass D, Carpenter CB, Schur PH, Alper CA (1979) Mapping of the structural gene for the second component of complement with respect to the human major histocompatibility complex. Am J Hum Genet 31:35–41
Tokunaga K, Omoto K, Araki C, Juji T (1980) Genetic polymorphism of the second component of human complement (C2) in Japanese. Jpn J Hum Genet 25:287–293
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Tokunaga, K., Araki, C., Juji, T. et al. Genetic polymorphism of the complement C2 in Japanese. Hum Genet 58, 213–216 (1981). https://doi.org/10.1007/BF00278714
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DOI: https://doi.org/10.1007/BF00278714