Deletion of the steroid 21-hydroxylase and complement C4 genes in congenital adrenal hyperplasia

J Med Genet. 1986 Jun;23(3):204-9. doi: 10.1136/jmg.23.3.204.


DNA was analysed from 20 patients with congenital adrenal hyperplasia due to cytochrome P-450 steroid 21-hydroxylase deficiency. Using probes recognising sequences in both the 21-hydroxylase gene and the adjacent fourth component of complement (C4), one patient was found to have a homozygous deletion of DNA which encompassed the C4B and 21-hydroxylase B genes. Evidence is presented for this deletion arising by recombination between homologous regions of 21-hydroxylase A and B. Seven patients appeared to be heterozygous for the same deletion, but no detectable alteration in the 21-hydroxylase gene could be demonstrated in others.

MeSH terms

  • Adrenal Hyperplasia, Congenital* / genetics*
  • Chromosome Deletion*
  • Chromosomes, Human, 6-12 and X*
  • Complement C4 / deficiency*
  • Complement C4 / genetics
  • DNA / genetics*
  • Heterozygote
  • Homozygote
  • Humans
  • Infant, Newborn
  • Phenotype
  • Polymorphism, Genetic
  • Recombination, Genetic
  • Steroid 21-Hydroxylase / genetics
  • Steroid Hydroxylases / deficiency*


  • Complement C4
  • DNA
  • Steroid Hydroxylases
  • Steroid 21-Hydroxylase