A high frequency of inherited deficiency of complement component C4 in Darwin Aborigines

Aust N Z J Med. 1987 Aug;17(4):420-3. doi: 10.1111/j.1445-5994.1987.tb00079.x.


A high frequency of serum complement component C4A deficiency may explain the higher prevalence and greater severity of systemic lupus erythematosus reported in Australian Aborigines. Inherited deficiencies of serum complement components C4A, C4B, and C2 were examined in two Australian Aboriginal populations from Darwin and Alice Springs and compared with the prevalence of complement deficiencies in white Australian blood donors. The frequency of C4A deficiency alleles was 29% in Darwin Aborigines compared with 12% in Alice Springs and 17% in Canberra blood donors. Partial C4B deficiency was also higher in Darwin Aborigines than in the other populations. Inherited deficiency of serum complement component C2 was not observed.

MeSH terms

  • Alleles
  • Chromosome Mapping
  • Chromosomes, Human, Pair 6
  • Complement C2 / deficiency
  • Complement C4 / deficiency*
  • Complement C4a
  • Complement C4b
  • Gene Frequency
  • HLA Antigens / genetics*
  • Humans
  • Oceanic Ancestry Group*
  • Phenotype


  • Complement C2
  • Complement C4
  • HLA Antigens
  • Complement C4a
  • Complement C4b