Nijmegen Breakage SyndromeMicrocephalyChromosome BreakageAtaxia TelangiectasiaSyndromeCell Cycle ProteinsNuclear ProteinsDNA Repair EnzymesChromosome DisordersAtaxia Telangiectasia Mutated ProteinsAbnormalities, MultipleImmunologic Deficiency SyndromesRadiation, IonizingDNA DamageChromosomes, Human, Pair 8Chromosomal InstabilityGenes, RecessiveDNA RepairRadiation ToleranceDNA-Binding ProteinsTumor Suppressor ProteinsExodeoxyribonucleasesEndodeoxyribonucleasesProtein-Serine-Threonine KinasesDNA Breaks, Double-StrandedFibroblastsCheckpoint Kinase 2Chromosome AberrationsMutationDNA Repair-Deficiency DisordersPhosphorylationCell CycleCells, CulturedCell Line