Bleomycin-induced chromosomal damage in tuberous sclerosis.

To investigate the possible involvement of mutagen-induced chromosomal instability in tuberous sclerosis the blood lymphocytes obtained from eleven patients with this disease and eleven healthy controls of comparable age and sex were exposed to bleomycin in vitro during the late S and G2 phases of the cell cycle. Neither the spontaneous aberration yields nor the bleomycin-induced chromosomal sensitivity differed between the two groups. The chromosomal distribution of 578 and 478 induced breaks in patients and controls, respectively, was similar. Thus, bleomycin-induced G2 chromosomal hypersensitivity in lymphocytes of patients with tuberous sclerosis is not an intrinsic feature of this hereditary disease.