, Volume 25, Issue 5, pp 299–304

Heterogeneity of human C4 gene size

A large intron (6.5 kb) is present in all C4A genes and some C4B genes
  • A. Palsdottir
  • R. Fossdal
  • A. Arnason
  • J. H. Edwards
  • O. Jensson

DOI: 10.1007/BF00404422

Cite this article as:
Palsdottir, A., Fossdal, R., Arnason, A. et al. Immunogenetics (1987) 25: 299. doi:10.1007/BF00404422


In this article we present a study showing that the human C4 genes differ in length because of the presence or absence of a 6.5 kb intron near the 5′ end of the gene. DNA from individuals of known HLA, factor B, and C4 haplotypes was analyzed for restriction fragment length polymorphism (RFLP) by Southern blot analysis with C4-specific cDNA probes. The RFLP patterns obtained showed that the C4 genes are either 22.5 kb or 16 kb in length. They are referred to as long and short C4 genes, respectively. A population study was carried out to examine the distribution of the gene size according to C4 allotypes and haplotypes. Long C4 genes included all C4A genes studied and also some C4B allotypes, e. g., B1 on most C4 A3B1 haplotypes. Similarly, C4B null genes were found to be of the long form. Other C4B allotypes tested were found to be coded for by short C4 genes, including B2, B1 in C4 A6B1 and C4 AQOB1 (with a single C4B gene haplotype).

Abbreviations used in this paper


fourth component of complement


second component of complement


factor B


major histocompatibility complex


restriction fragment length polymorphism


ethylenediaminetetraacetic acid


lauryl sulfate, sodium salt

Copyright information

© Springer-Verlag 1987

Authors and Affiliations

  • A. Palsdottir
    • 1
  • R. Fossdal
    • 2
  • A. Arnason
    • 2
  • J. H. Edwards
    • 3
  • O. Jensson
    • 2
  1. 1.MRC Immunochemistry Unit, Department of BiochemistryUniversity of OxfordOxfordEngland
  2. 2.Genetics DivisionThe Blood BankReykjavikIceland
  3. 3.Genetics Laboratory, Department of BiochemistryUniversity of OxfordOxfordEngland