Fibroblasts of P2 were irradiated with 5Gy and γH2AX foci were counted in at least 50 cells using a Fluoview FV 1000 confocal microscope (Olympus) with an UplanApo 60x/1.2na water lens (Olympus) at given time points after IR. Numbers of γH2AX foci/cell are compared to the established LIG4-deficient cell line 411BR [11] and a healthy control (a). PBMCs from patients P1-P3 and two controls C1-C2 (healthy siblings III.2 and III.3) were irradiated with 10Gy, and γH2AX was assessed by flow-cytometry. The γH2AX fold induction was calculated by dividing the mean fluorescence intensities (MFI) of unirradiated cells by the MFI of irradiated cells of each time point (* p≤0.05) (b).
Telomere length in lymphocytes (c) and granulocytes (d) is expressed relative to healthy age-matched controls. The colored lines represent percentile thresholds. In two controls, granulocyte event numbers were too low to measure the telomere length with confidence.