Differential bleomycin susceptibility in cultured lymphocytes of fragile X patients and normal individuals.

The frequency of bleomycin-induced chromatid breaks was studied in cultured lymphocytes from ten fragile X patients and ten healthy controls. The results showed that the frequency of chromatid breaks was significantly higher among fragile X patients than among normal individuals. We suggest that the fragile X patients may be more susceptible to mutagens and carcinogens and, therefore, more prepotent to neoplastic induction.