DNA polymorphism of human HLA-linked complement C4 allotypes, including C4 null alleles, in the Finnish population.
Human HLA-linked complement C4 gene products, C4A and C4B, show extensive genetic polymorphism. In both loci, an allele without a gene product, C4 null, is also observed. We have performed a restriction enzyme analysis of genomic DNA samples from individuals having all common (frequency over 1%) C4 protein allotypes observed in the Finnish population. Only one allotype-specific RFLP marker was observed. With some enzymes a DNA polymorphism was observed, which was not detectable by C4 protein typing. Analysis of 10 different C4B null haplotypes and 4 C4A null haplotypes suggested that only one haplotype, HLA-B8 C4A0 B1, carried a C4A gene deletion. This was observed in all 4 unrelated individuals homozygous for this haplotype.
D000483:Alleles; D002872:Chromosome Deletion; D003181:Complement C4 / Q000235:genetics*; D015934:Complement C4a; D015935:Complement C4b; D004247:DNA / Q000235:genetics; D005387:Finland; D008040:Genetic Linkage; D006680:HLA Antigens / Q000235:genetics*; D006239:Haplotypes; D006801:Humans; D012150:Polymorphism, Restriction Fragment Length
D003181:Complement C4; D006680:HLA Antigens; D015934:Complement C4a; D015935:Complement C4b; D004247:DNA