Patient fibroblasts display replication-associated DNA damage. A Representative images from imaging flow cytometry analysis of γH2AX staining in healthy control and patient fibroblasts. DRAQ5 dye was used to stain the nucleus. Original magnification × 40. B Quantification of γH2AX foci per cell. 252, 244, 287 cells were counted respectively for healthy control 1, healthy control 2, and the patient. Image analyses were performed using CellProfiler, v2.0. Results represent median + min to max.****p < 0.0001, Mann–Whitney test