The cell cycle of lymphocytes in Fanconi anemia.

BrdU-incorporation techniques were used to study the cell cycle in 18 cases of Fanconi's anemia (FA). By comparison with controls, a significant slowing of the cell cycle of lymphocytes in vitro was observed in all FA patients, and possibly in FA heterozygotes, although to a lesser degree. It is probable that the demonstration of the slowing is dependent on the culture conditions. No slowing was observed in other patients affected by at least one of the symptoms of FA. The slow cell cycle of FA cells is mostly due to a very long G2-phase. A relationship between slow cell cycle and chromatid anomalies exists, the slower cells being significantly more frequently carriers of radial figures than the faster cells, in the same patient.