Figure 3.

Cell-cycle analysis after ³H-thymidine-pulse-labeling of logarithmically growing lymphoblast cell lines from both siblings. The cells were treated for 10 min with 1 μCi/ml ³H-thymidine (104, 7 Ci/mmol; specific activity: 104 Ci/mM) and were harvested for chromosome preparation at 1-h intervals. The numbers of labeled and unlabeled pro- and metaphase cells was determined after autoradiography for patient 1 (triangle), patient 2 (square), and a control (circle). Gray symbols give the percentage determined in an independent second experiment 2 h after pulse labeling.