From the case: Variant ataxia telangiectasia
Patient's blood was exposed to 1 Gray of gamma rays. Chromosomal radiosensitivity of the T lymphocytes was exposed. There were 26 cells with 21 bits of damage compared with 8 bits of damage in the normal control in 50 cells consistent with a moderate increase in chromosomal radiosensitivity. In classic AT, a 5-10 fold increased level of gamma ray induced chromosome damage.