Susceptibility of chromosomes from patients with Down's syndrome to 7,12-dimethylbenz(a) anthracene-induced aberrations in vitro
✍ Scribed by R. L. O'Brien; P. Poon; E. Kline; J. W. Parker
- Publisher
- John Wiley and Sons
- Year
- 1971
- Tongue
- French
- Weight
- 537 KB
- Volume
- 8
- Category
- Article
- ISSN
- 0020-7136
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✦ Synopsis
Abstract
The susceptibility of chromosomes from seven patients with Down's syndrome to damage in vitro by 7,12‐dimethylbenz (a)anthracene (DMBA) was significantly greater than that of the chromosomes from ten healthy donors. Chromatid gaps or breaks comprised the vast majority of aberrations produced in the chromosomes of both groups. Small numbers of isochromatid exchanges and dicentric chromosomes were also observed. The lymphocytes of patients with Down's syndrome were not deficient in their ability to repair DNA damage induced by ultraviolet light or 4‐nitro‐quinoline‐N‐oxide and, at the doses used to produce chromosomal aberrations, DMBA did not significantly inhibit either replicative DNA synthesis or the repair of damage induced by ultraviolet light or 4‐nitroquinoline‐N‐oxide in normal lymphocytes or in those from patients with Down's syndrome. DMBA did not stimulate unscheduled DNA synthesis in the lymphoeytes from patients with Down's syndrome or from normal controls.