Xeroderma pigmentosum (XP) and Cockayne syndrome (CS) are diseases provoked by mutations in multifunctional proteins that are involved in DNA repair. DNA-repair deficiency explains the high cancer incidence of XP, whereas cancer-free CS, characterized by growth retardation, neurological degeneration, and premature aging does not present as a classical DNA-repair deficiency disorder. Here, we compared a severe combined XP/CS ca...