Radiation sensitivity of Down's syndrome fibroblasts might be due to overexpressed Cu/Zn-superoxide dismutase (EC

Eur J Cell Biol. 1989 Feb;48(1):79-87.


Trisomy 21 (Down's syndrome, DS) is the most frequent chromosomal aberration. Triplication of a small region of chromosome 21, the fragment 21q22 is sufficient to cause the DS phenotype including immunodeficiency, premature aging, neurodegenerations, mental retardation and an increased risk of leukemia. Chromosomal aberrations caused by X-ray irradiation were observed in DS lymphocytes and DS fibroblasts, but the correlation to cell death or repair deficiency was not clear. We approached this problem and report here on a profound X-ray repair deficiency of DS cells. With a colorimetric viability assay we observed an UV sensitivity of DS fibroblasts at doses beyond 14 Jm-2 but no significant X-ray sensitivity. By the nucleoid sedimentation technique, a deficient restoration of nucleoids in DS cells after X-ray irradiation was demonstrated. The same features apply for cells, which contain an overexpressed Cu/Zn-superoxide dismutase (SOD-1) gene. Radiation sensitivity of DS cells and SOD-1 overexpressing cells resemble those of ataxia telangiectasia (AT) fibroblasts. Additionally, DS and AT cells exert lack of inhibition of DNA synthesis after X-ray irradiation.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Cell Line
  • Cells, Cultured
  • Copper / metabolism
  • Down Syndrome / etiology
  • Down Syndrome / genetics
  • Down Syndrome / pathology*
  • Fibroblasts / radiation effects*
  • Gene Expression Regulation / radiation effects
  • Humans
  • Superoxide Dismutase / genetics*
  • Superoxide Dismutase / metabolism
  • Superoxide Dismutase / radiation effects
  • Transfection / radiation effects
  • Ultraviolet Rays / adverse effects
  • X-Rays / adverse effects
  • Zinc / metabolism


  • Copper
  • Superoxide Dismutase
  • Zinc