RESUMO
Background: In ataxia telangiectasia (A-T), the lack of a functional ATM kinase is associated with disturbances in the processing of DNA damage and a chronic oxidative stress. These disturbances may be responsible for an increment of chromosomal damage in A-T cells. Aim: To study the in vitro effect of vitamin E (DL-a-tocopherol) on the frequency of chromosomal damage of lymphocytes from patients with A-T. Patients and methods: Seven patients with A-T and age-sex matched controls were studied. Chromosomal damage in mitosis was evaluated in lymphocytes cultures both under basal conditions and when G2 repair was prevented by 5 mM caffeine. Results: In cells from patients with A-T, vitamin E induced a 57.1 and 47.9 percent decrease in chromosomal damage under basal and inhibited G2 repair conditions, respectively. However, there was a non significant improvement in their repair activity. Vitamin E effects on chromosomal damage was not significant in control subjects. Conclusions: Vitamin E reduces chromosomal damage in lymphocytes from patients with ataxia telangiectasia