The repair of DNA single strand breaks in human cells with genetical disorders.

The aim of this work was to make a preliminary examination of 
some hereditary diseases, related to precocious aging in order to determine 
whether the defects involved resulted from an impairment of the DNA 
repair capacity. To test for an impairment in DNA single strand 
capacity, in cells from patients with different diseases, we have followed 
the rate of the DNA after X-irradiation by sedimentation on alkaline 
sucrose gradients. It was found that all cells observed from Lesh 
Nyhan, cystic fibrosis, trisomy 15 et 21, retinoblastoma, were able to 
repair the single strand breaks in their DNA to the same 
extent and at the same initial rate. 