[Detection of heterozygotes for ataxia telangiectasia using sensitivity to ionizing radiation]

Recent research have demonstrated that homozygotic and heterozygotic patients with ataxia telangiectasia (AT) show chromosomal rupture. Taking in consideration this characteristic, a study was designed, inducing chromosomal breaks in granulocytes from patients with AT, and heterozygotic carriers of AT compared with a group of healthy individuals. The number of chromosomic ruptures induced by 14 doses of radiation at 125 KV and 125 mA, was measured in all of them. Results suggest significant differences in the number of chromosomal structural alterations induced by radiation in granulocytes from heterozygotic carriers of AT, similar to structural alterations in lymphocytes from patients with AT. It is demonstrated that these alterations occur preferentially in one group C chromosome, both in homozygotic and heterozygotic patients with AT.