Down's syndrome with a recombinant tandem duplication of chromosome 21 derived from a maternal ring

J Med Genet. 1984 Aug;21(4):310-4. doi: 10.1136/jmg.21.4.310.

Abstract

An account is given of the cytogenetic investigations of a girl with Down's syndrome found to have a dicentric duplication of chromosome 21. This tandem type of rearrangement was interpreted as a recombinant derived from a single meiotic crossover between a maternal ring 21 and its normal homologue. A population of cells was also found in which breakage of the dicentric resulted in a chromosome 21 with a small terminal deletion. The mother and the proband's younger brother, who was also a ring 21 heterozygote, were both clinically normal.

Publication types

  • Case Reports

MeSH terms

  • Adult
  • Amniocentesis
  • Chromosome Aberrations*
  • Chromosome Banding
  • Chromosomes, Human, 21-22 and Y*
  • Down Syndrome / genetics*
  • Female
  • Humans
  • Infant, Newborn
  • Karyotyping
  • Male
  • Meiosis
  • Pregnancy
  • Recombination, Genetic
  • Ring Chromosomes*