Figure 1.

Mutation in the ATM gene in the pathogenesis of A-T. The defective ATM gene results in the disruption of DNA repair mechanisms that are critical for maintaining the integrity of genomic DNA and subsequent accumulation of unregulated DNA damage. An absence or deficiency of ATM protein contributes to the impairment of mitochondria, leading to excessive production of ROS. Dysregulated ROS signaling further accelerates DNA damage. ATM, ataxia-telangiectasia mutated; ATP, adenosine triphosphate; DNA, deoxyribonucleic acid; MMP, mitochondrial membrane potential; ROS, reactive oxygen species.